This month’s open thread on climate topics as 2025 wraps up. Please be courteous to each other. Tis the season!
Reader Interactions
252 Responses to "Unforced Variations: Dec 2025"
Mal Adaptedsays
I call RC readers’ attention to Zeke Hausfather’s blog post last week: https://www.theclimatebrink.com/p/consensus-machines. He offers a brief but helpful tutorial on how generative AIs arrive at their results, But first he says:
Zeke: there is a case to be made that the transition toward using LLMs as sources of knowledge might end up inadvertently recentering scientific expertise and creating a more unified information landscape for society.
If his explanation is accurate, I can see how that might work. But you should argue with him, not me, as my ignorance of the technology is still encyclopedic.
Two categorical aspects to current A.I. — (1) the use of LLMs to pattern match how humans convey (writing, visuals) or process information (software development) and (2) the use of NNs and related tools to train on data as a way to make predictions or solve problems.
The latter can be used in climate science, but it’s not clear what breakthrough it will discover. And if it does discover something, reverse engineering it will still be a pain. Yet, there is still work to be done hammering away via human ingenuity, such as this for modeling fluid dynamics => https://geoenergymath.com/2025/12/02/hidden-latent-manifolds-in-fluid-dynamics/
I also missed he paper in the link below when it first came out, but in it Pierrehumbert describes how and why climate scientists were awarded the Nobel Prize in Physics: Fluid Mechanics: the quintessential complex system
How things can change in a few years.
zebrasays
Thanks for the Pierrehumbert reference… should be required reading before commenting here.
The ERA5 global SAT anomaly for November averages out at +0.65°C, down on October’s +0.70°C and a sliver below September’s +0.66°C.
The last three months sit above the summer months which averaged +0.47°C.
But November was different from Sept/Oct. The ERA5 numbers at the Uni of Main’s Climate Re-analyser site show November was warmer due to a warm northern hemisphere, (this due to the now-normal warmer NH Autumns that result from AGW. This NH Autumn wobble is usually smaller during La Niñas and the ENSO watchers are showing we have weak La Niña conditions.)
Unlike November, in Sept/Oct the higher SAT anomalies were due to a warmer southern hemisphere and in particular due to unusual Antarctic temperatures which experienced a big warm wobble.
A more reliable (less wobbly) measure of global temperature, the ERA5 60N-60S SST anomaly dropped to an average of +0.29°C for November, this now down below (just) levels projected prior to the “bananas!!” temperatures of 2023/24, the first time since Feb 2023.
(See graphics various at the Banana!! Watch page.)
Ok, since I can not post a chart here, let me give you the data. Left column are the surface temperatures in the tropics (30°N-30°S) as taken from Ramanathan 2005. In the right column are the average lower troposphere temperatures also within the tropics (30°N-30°S) from the UAH data set.
Max – Min equals 1.17K for Ts and 0.47K for Tlt. The variation of Tlt thus is 60% smaller than that of Ts. Ramanathan argued there was a very strong greenhouse effect in the tropics, and even “super GHE” in the inner tropics. That is because tropical dOLR/dTs is almost zero and partially below zero in the inner tropics. As the surface warms in the annual cycle, there is barely an increase in outgoing longwave radiation, ie the system can not cool itself.
The implicit assumption is that the increase in WV with warming would almost perfectly negate the otherwise to be expected Planck Response. So if you assume a tropical Planck Respone of say 3.5W/m2, while you observe dOLR/dTs ≈ 0, that would indicate the presence of a total of 3.5W/m2 positive feedbacks. Depending on whether you sample for skies only or not, that could also include a cloud feedback component. And most notably, the lapse rate feedback component is assumed to be negative.
WVF + CF + LRF = 3.5
For example you could solve this restriction then like WVF = 4, CF = 0.5, LRF = -1. A strong positive WVF and some neg. LRF. By sampling for clear skies one can try to eliminate the CF variable.
Anyway, the problem is documented in the data above. With Tlt being so sluggish relative to Ts, there is no negative LRF component, but instead it must be a huge positive LRF compoent, like 2.1W/m2, if we assume Tlt as a proxy for Tz. Of course there is no actual positive “lapse rate feedback” in this instance, it is just, let us call it, tropospheric temperature autonomy.
It then follows there is just a small WVF (+CF) residual of only 1.4W/m2. That is a very moderate WVF (+CF), easily to be dominated by a much larger negativ LRF with long term warming. And of course that is no “super GHE”..
Barry E Finchsays
I’ve not time to study E. Schaffer comment but anybody who has I suggest you look at what must be about 27 million clear-sky “greenhouse effect (GHE)” measurements for 1998-2014 for 63,000 equal area locations around Earth (grid pixels) at 2:27 at https://www.youtube.com/watch?v=NNgMyDRWWrA This of course is because LWIR-active GHG molecules “absorb” & “manufacture” photons and do not “absorb photons and re-emit 50% back down again”, especially not “to the surface”.
Then there’s fluid dynamics, an entirely-different and vastly-important aspect of Earth’s climate with it’s 2 big fluids “water” and “air”, about which I know bits and bobs but not much. I know they shift energy around Earth at like ~6,000 terawatts and from ocean to land at like ~2,200 terawatts.
MA Rodgersays
Barry E Finch,
Myself, I would hope nobody wastes their time with the E. Schaffer comment above. There’s a lot of strange stuff that doesn’t add up and if you visit the weblink provided by E. Schaffer to find some clarity, you arrive at what he styles “The Greenhouse Defect – Saving the planet …from idiocy – The most disruptive site on climate science.”
An exemplar of the strange stuff in his comment is the insistence that “you observe dOLR/dTs ≈ 0” when, he suggests, the expectation would be something of the order of 3.5Wm^-2/deg C. CERES data shows a healthy annual OLR cycle averaging 3.4Wm^-2 peak-to-peak, not a double-peaked cycle as seen in Tropical SAT but big enough to show dOLR/dTs ≠ 0.
Your confused presentation does not entice me into trying to understand properly what you are about but I would suggest your seeming mission to find fundamental flaws in the science supporting AGW by identifying some “unthinkable … blunder (that) went unnoticed for decades”: this mission is likely a fools errand.
Concerning specifically the tropical “super GHE” which you seem to want to paint as some figment of errant modelling, a quick look at the CERES data (Clear sky OLR 30N-30S) alongside ERA5 SAT (30N-30S) might just give a measure of your “WVF + LRF” w.r.t. SAT. With that thought in mind, see the graphic here – POSTED 6th December 2025.
Barry E Finchsays
MAR, actually the dOLR/dTs < 0 is a reality, as a best-fit trend, from CERES analysis. It's at https://www.youtube.com/watch?v=NNgMyDRWWrA at 2:27 with surface temperature increasing from ~299.5K to ~302.2K the OLR goes down from ~289 w/m**2 to 286 w/m**2, an apparent Super GHE, then rapidly returning, to the linear trend from ~302.2K to ~302.7K. However, it's a best-fit trend from a huge hash of measurements with wide range and seems likely to me that it's to do with some regional variability thing so, sort of, if there's 299.5K in some specific place and 302.2K in some other specific place then for these specific places there's clear-sky OLR of 289 w/m**2 at that specific 299.5K place and of 286 w/m**2 at that specific 302.2K place.
I greatly doubt that the trend through the vast hash plot means that when that 299.5K place warms to 302.2K its OLR goes down. I think its OLR goes up and what's being shown is comparing differing regions with something different between them that causes them not to respond identically. Tropical ocean SST typical is in that range but I don't know the relevance.
One needs to be careful about what perspective is in play. In this video, as far as I have seen it, they exclusive talk about the regional proxy. It is no secret this proxy does not work and is obsolete. Let me quote Dessler et al 2008:
“This is a quantitative estimate of the effect of the changing lapse rate on dOLR/dTs, and it shows that it is negative for almost all values of Ts. In other words, as Ts increases, so does the lapse rate, and the general effect of this is to reduce dOLR/dTs, and therefore OLR, below what they would be if the atmosphere maintained a constant lapse rate.
In most climate-change scenarios, the upper troposphere is expected to warm more than the surface, and the additional radiation from a warmer upper troposphere will act as a negative feedback on the warming.
This result demonstrates the unsuitability of using variations in different regions in our present climate as a proxy for climate change.”
The reason why there is such a reversal of the trend is with the inner tropics. There you have strong convective clouds, optically thick, reaching up to high altitudes and low temperatures. This of course reduces OLR.
Ramanathan however deals with the seasonal proxy and derives the “super GHE” from that perspective.
Barry E Finchsays
E. Schaffer says 8 Dec 2025 (with no “Reply” button on my screen, some weird hosting site thing I suppose) “The reason why there is such a reversal of the trend is with the inner tropics. There you have strong convective clouds, optically thick, reaching up to high altitudes and low temperatures. This of course reduces OLR. The CERES plot that I referenced is stated as being measurements for cloud-free skies only.
Then thinking about it, it is somewhat odd. Is says “nighttime, clear-sky measurements of OLR” – I mean where are nightime temperatures reaching 310K and more?! Maybe right after sunset, idk. Anyway..
If it is a straight line with nightime temperatures, but features are “bulge” during day time (or all time), that would suggest it is mainly due to the size of the atmospheric window. From previous analyses I tend to believe the clear sky window is about twice (if not more) the size in the outer- and in the inner tropics.
With otherwise identical Ts it might mean a difference of 40-50W/m2 in the share of surface emissions in OLR. OLR itself will then be way more sensitive day time heat in the outer tropics. Would explain why it is straight line for nighttime OLR..
Barton Paul Levensonsays
BEF: LWIR-active GHG molecules “absorb” & “manufacture” photons and do not “absorb photons and re-emit 50% back down again”, especially not “to the surface”.
BPL: Not sure what you’re saying here. There is definitely atmospheric back-radiation; we can measure it with instruments.
zebrasays
BPL, he’s trying to be precise about the language.
Photons are converted to energy within the molecule; the energy may be re-emitted or transferred to other molecules through physical interaction. (I believe the latter is the primary mechanism.)
And if the energy is re-emitted downward as a “new photon”, that photon isn’t likely to make it to the surface before being absorbed.
Barry E Finchsays
Zebra yep, not at all just a matter of phrasing as bods kept telling me on various Social Media (because everybody assigns their time and interests and they got involved without being interested). There’s an obvious fundamental difference regarding a popular type of Fossil memes, some variants of them, the last couple decades. Isn’t there? As I first posted on RC UV as a Trial Balloon years back to judge interest but was censored, then tried again 6 months later with something obtuse to check the censorship. You & MAR exchanged briefly and MAR noted that I’m crazy, which of course is correct but not relevant to radiative physics, which couldn’t care less about humans.
Barry E Finchsays
Barton. I’m not sure why you’re not sure. Looks crystal clear to me and it’s correct in overall essence per orbiting measurement since 1964 IRIS-A on Nimbus 1.
“atmospheric back-radiation; we can measure it with instruments”. Yep the down-welling radiation is measured at land surfaces and I think on Research Vessels. Please indicate how the pyrgeometers identify that these photons entering the sensor were absorbed from below by H2O gas, CO2, CH4, O3, N2O, CFCs molecules (the GHGMs) and then re-emitted back down again as you strongly claim, rather than being photons that were manufactured by the GHGMs as I strongly claim since July 2018 and you strongly refute (Me: when GHGMs collide they sometimes, not often, vibrate, maybe rotate I’ll call it all “oscillate”, as a result and then they sometimes, not often, emit a photon as a result of oscillating. BPL: Nope, they can’t do that, GHGMs are third-rate, defective molecules). On terminology I greatly prefer “down-welling radiation”, because its clear because all understand what “down” means, to “back-radiation” which is meaningless.
Certain molecules and atoms in solids, liquids and gases at certain temperatures are manufacturing photons all the way from the centre of Earth’s core to the top of Earth’s atmosphere. Right? This manufacture doesn’t stop at what we call “the surface”, does it?, it tapers off as gas concentration increases with altitude.
If the ocean somewhere geographically is divided into 27,500,000 layers each 200 microns thick then the H2O molecules in each layer are manufacturing photons and when not manufacturing photons they are either oscillating because they absorbed a photon or doing no manufacturing or absorbing, just “jiggling” with the energy that doesn’t involve photons. Each layer 200 microns thick emits ~460 w/m**2 of photons from its upper and its lower surface when it’s at 27 degrees, ~390 w/m**2 from its upper and its lower surface when it’s at 15 degrees and ~315 w/m**2 of photons from its upper and its lower surface when it’s at 0 degrees. Obviously, the molecules in each layer absorb photons entering from above and below and absorb some portion of their own photons. The ~315 w/m**2 of photons manufactured in the lowest layer 200 microns thick goes from its lower surface into the sea bed and the ~390 w/m**2 of photons (varying ~305 w/m**2 to ~460 w/m**2) manufactured in the highest layer 200 microns thick goes from its upper surface into the atmosphere.
The molecules and atoms from Earth’s core to its surface must be doing the same as the ocean, with the photon fluxes being much vaster.
The N2, O2, Ar molecules don’t manufacture non-negligible amounts but the GHGMs manufacture large photon quantities but not like the solids and liquids quantities because gas density is far lower. Take radiation of 4.5 – 100 microns wavelength except exclude 8.0-9.0 & 10.0-13.0 microns. Suppose the GHGMs in the lowest 200 m of atmosphere absorb all photons going in from above and below. The GHGMs in such a tall layer will also absorb most of the photons they manufacture but there will be leakage from its upper and its lower surface, which are 200 m apart. The leakage from its lower surface is what you (and presumably physicists) are calling “back-radiation” for no meaningful reason because that radiation isn’t going back anywhere. I call it “down-welling radiation” (except when the Gang Du Jour is using “back-radiation” and I don’t want to detract with wordiness from whatever the main point, such as “it’s 0.04%!!” or whatever).
The leakage from its upper surface enters the 200 m of atmosphere above. And so on. Obviously, this is simplified and physicists calculating quantities must determine the photon fluxes up & down from each layer (I know that William & Will Happer used 100 m layers, I don’t know whether that’s typical) and include the portion that can go through the layer. Obviously, the layers would need to get increasingly tall with altitude if one wanted to guarantee that each layer was 100% opaque to photons passing entirely through it, but I’m inferring that physicists don’t do it that way. I’m rather sure that that’s the correct physics as close as matters though and I’m not sure what you’re not sure about with that simple-enough thing. If there are 2 suitably-sized parcels of matter with a common boundary they exchange radiation with the warmer radiating more into the cooler than the cooler radiates into the warmer. Applies to solids, liquids and GHGMs.
On some Social Media places like GoogleysTubes I’d sometimes offer anybody interested to ask me why that isn’t just semantics and then I’d be willing to consume time (for no income) explaining why but I never found interest, just some stupid, ignorant replies such as “@mrunning10 Reported again. Because you’re insane” from the Trolls who are probably the grandsons of the Trolls around here. That’s Life.
Neurodivergentsays
Barry E Finch says
On some Social Media places like GoogleysTubes I’d sometimes offer anybody interested to ask me why that isn’t just semantics and then I’d be willing to consume time (for no income) explaining why but I never found interest, just some stupid, ignorant replies such as “@mrunning10 Reported again. Because you’re insane” from the Trolls who are probably the grandsons of the Trolls around here. That’s Life.
Neurodivergent responds; nah couldn’t be you who’s the mad hatter incoherent mad troll. nah, never. It’s everyone else who oppressing’ ya freedumbs dude.
jeez get lost, seriously. or get some therapy.
Barton Paul Levensonsays
BEF: On terminology I greatly prefer “down-welling radiation”, because its clear because all understand what “down” means, to “back-radiation” which is meaningless.
BPL: It’s the accepted term. Like “greenhouse effect,” it may not be strictly accurate, but it’s too late to change the usage.
mass absorption coefficient k_a for the air
= absorption cross-sectional area per unit mass of air [m²/kg]
= Σ_i ( n_i · σ_{a,i} ) ÷ ρ_{air} )
At any given POV, there is some (spectral) radiance ((spectral) brightness) L_ν you see coming from the direction (θ,ϕ); move backward a tiny (infinitesimal/differential) distance ds along the LOS to put additional material in front of you, with optical thickness dτ; because of the tiny amount of this added τ, we can proceed assuming none of its absorption cross sections σ_a overlap. Thus, the fraction of L_ν (seen looking from POV) which is blocked and replaced by the glow B_ ν of that added dτ is that dτ. Ie. The change in L_ν over ds is:
Then integrate over s or τ or z or mp ( |d(mp)|= | ρ_{air} · dz | )…
Exact analytic solutions can be found for some cases eg.
where τ is measured along LOS, in the direction the light is going (you’re looking toward smaller τ in this context), from a point where L_ν = L_{ν,0} & B_ν = B_{ν,0} .
Constant B_ν :
L_ν = B_ν + ( L_{ν,0} − B_{ν,0} ) · exp(−τ)
asymptote: radiance lags behind by 1 unit of τ , ie.
L_{ν,asymp} = B_ν
Linear B_ν = B_{ν,0} + a·τ :
L_ν = B_ν ( τ ) – a + ( L_{ν,0} − B_{ν,0} ) · exp(−τ)
asymptote: radiance lags behind by 1 unit of τ , ie.
L_{ν,asymp} = B_ν ( τ − 1 ) = B_ν ( τ ) – a
More generally, the solution is an asymptote L_{ν,asymp} ( τ ) for a particular function of B_ν ( τ ), plus an exponentially decaying term that is
L_ν − L_{ν,asymp}
at any given τ
(which may be nonzero because that particular function of B_ν ( τ ) may only apply over a limited domain of τ; the decaying perturbation is coming from the L_ν entering that domain).
Φ (radiant) flux: rate of energy flow, ie. power: [J/s = W]
flux density: flux per unit area (through an area): [W/m²]
I intensity: flux per unit solid angle, in a direction: [W/sr], eg. through an area of some orientation
(note the word “intensity” is often used for other things, though)
L radiance: flux density per unit solid angle, in a direction, through an area facing that direction: [W/(m²·sr)] If you focus at ∞ (infinite distance), then, with some caveats***, radiance corresponds to the brightness you see at a point in your visual field.
spectral ___ ≡ amount of ___ per unit of the spectrum (at a given point in the spectrum).
Eg., over ν: [W/THz] , [W/m²·THz] , … , [W/(m²·sr·THz)] ,
over \tilde{\nu} : [W/(m²·sr·cm‾¹)],
over λ : [W/(m²·sr·µm)]
over E : [W/(m²·sr·eV)]
Now just multiply by the |cos(θ)| (or cos(θ)) & integrate over solid ange Ω to get spectral flux density Fd_ν (The standard symbol is E_ν or E if not spectral, but that could be confusing…
upward and downward flux densities: Fd↑ , Fd↓
net upward flux density: Fd↑net
net downward flux density: = − Fd↑net )
d [ Fd(↑,↓)_ν ] = L_ν(↑,↓) · |cos(θ)| · dΩ
(you can think of radiance L as the intensity I per unit area facing the direction of L ( ie, (θ,ϕ)); multiplying by the |cosine of θ| gives the intensity per unit horizontal area. PS I’m skipping over some fine points on my L_ν(↑,↓) & θ notation…)
dΩ = sin(θ) dϕ dθ
but for PPIA we can just use dΩ = 2π sin(θ) dθ
and then *(if I remember right)* we get asymptotic values for the linear case:
Fd↑_ν = π (B_ν + ⅔·Γ_{Bτ})
Fd↓_ν = π (B_ν − ⅔· Γ_{Bτ})
Fd↑net = ⁴/₃· Γ_{Bτ}
L_{ν,asymp} = B_ν − Γ_{Bτ} · cos(θ)
where Γ_{Bτ} = ∂(B_ν) / ∂(τ_{vc}) (ie the lapse rate in terms of (based on) the Planck function and vertical optical depth)
The decay of Fd toward its asymptote is more complex than a simple exp(−∆τ_{vc}), and depends on the directional distribution of L. Interesting case: if you have an inversion layer above a(n isothermal) cloud layer, for some levels of opacity, you can get net radiant heating in the uppermost part of the cloud and net net radiant cooling deeper in the layer, both due to the radiances from above. If the overlying atmosphere is not too opaque, but opaque enough, L↓ from near vertical can be dimmer (colder) than B of the cloud, while L↓ from closer to horizontal can be brighter (hotter) than the cloud’s B. The L closer to vertical penetrates deeper into the cloud; L farther from vertical is absorbed over a shallower layer. Compare to https://scienceopinionsfunandotherthings.wordpress.com/2024/12/10/directionally-averaged-radiance-and-the-semi-gray-skin-temperature-wip-awaiting-final-proofread-double-check-diagrams-pending/ (see last part: *†* …”Meanwhile, the anomalously brighter radiance near vertical penetrates deeper below TOA than the anomalously darker radiance near horizontal “…)
****(please post this in place of last submitted comment)****
complete correction, skipping the ν subscript: τ increasing in the direction the light L is going (you’re looking toward smaller τ in this context), from a point where L = L_0 , B = B_0 . Constant B :
L = B + ( L_0 − B_0 ) · exp(−τ)
L’_0 = ( L_0 − B_0 )
L_{asymp} = B
—-
Linear B = B(τ) = B_ 0 + a·τ :
L = ( B – a ) + [ L_0 − ( B_0 − a ) ] · exp(−τ)
= L_{asymp} + [ L_0 − L_{asymp,0} ] · exp(−τ)
= L_{asymp} + L’_0 · exp(−τ)
= L_{asymp} + L’
asymptote: radiance lags behind by 1 unit of τ , ie.
L_{asymp} = L_{asymp}(τ) = B(τ−1) = B(τ) – a = B – a
…
d [ Fd(↑,↓) ] = L(↑,↓) · |cos(θ)| · dΩ
… for PPIA we can use dΩ = 2π sin(θ) dθ
“and then *(if I remember right)* we get asymptotic values for the linear case:”
L_{asymp} = B − ΓBτ · cos(θ) for θ = 0° to 180° , (L coming from zenith angle θ)
ie.:
L↑_{asymp} = B + ΓBτ · cos(θ) for θ = 0° to 90° (L going toward zenith angle θ)
L↓_{asymp} = B − ΓBτ · cos(θ) for θ = 0° to 90° (L coming from zenith angle θ)
Fd↑_{asymp} = π ( B + ⅔·ΓBτ )
Fd↓_{asymp} = π (B − ⅔·ΓBτ )
Fd↑net_{asymp} = π · 4/3 · ΓBτ
where ΓBτ = ∂B / ∂(τ_{vc}) (ie the lapse rate in terms of (based on) the Planck function and vertical optical depth)
mp = vertical mass path (measured downward from TOA) [kg/m²], and
k_a = mass absorption coefficient : [m²/kg]
τ_{vc} = vertical optical depth (measured downward from TOA) : [m²/m²]
—-
Generally, you’d want to do a numerical (approximating) integration – over a vertical coordinate (eg. z, p, p/p_{sfc}, mp, τ_{vc}, …
dp = −g · ρ · dz = −g · d(mp)
d(τ_{vc}) = k_a · d(mp) = μ_a · dz
β_a ≡ μ_a = Σ_i ( n_i · σ_{a,i} )
**(isotropic absorption σ_{a,i})**
…),
over solid ange Ω, and over the spectrum.
over a vertical coordinate: an obvious choice is to just directly use dL = ( B − L ) · dτ , ie. approximate the local atmospheric column as a set of thin-enough isothermal layers from i=0 to … (from TOA) (PS index i refers to the layer and to it’s upper boundary (lower boundary of the i−1 layer), ie. TOA is i=0. L↑(TOA) = L↑[i=0]… ; ∆mp[i] = mp[i+1] – mp[i] , …)
But a step up in sophistication would use an approximation of the profile as a set of linear segments, so the decay to a linear asymptote can be used, ie. (PPIA … TBC…) – another step up could use parabolic segments, etc… TBC… You could even use a set of B = linear superposition of sinusoidal terms; the L and Fd values for each term would sum (for each ν – ∆τ[i] for each ∆mp[i] will vary over ν, as will the shape of B(mp) ). But you might want to have values calculated for some vertical resolution, such that there might not be much more to gain from such levels of sophistication…
PS note – if you actually have a B profile with linear segments with sharp features, using the
(spectral) net radiant cooling, per unit mass (of air):
NCm_ν = 4π sr · ( B_ν – L_{ν,4π} ) · k_{a,air}
formula at mp[i] works; but for a good sense of how NCm_ν varies spatially, you’ll want higher vertical resolution getting closer to the sharp turns in ∂B/∂( τ_{vc}) (lapse rate discontinuities) and discontinuities in B(τ_{vc}) (eg. TOA). And/but If you are approximating a smooth curve with a series/set of linear segments, this formula will work ≈ okay (AFAIK) if the ∆τ_{vc}[i] = k_a[i] * ∆mp[i] are small enough, but as they get large, the you’ll get spurious nonzero NCm_ν results, due to the lapse rate discontinuities; the NCm_ν values between the discontinuities will go to 0 as they should, but you’re not calculating those values, and so a graph will only show the erroneous remnant nonzero NCm_ν results. So it’s better to calculate & graph
discontinuity in B(τ_{vc}): use a ∆τ_{vc}[i] = 0 so that you can calculate two NCm_ν values at same τ_{vc}.
——- —
“parabolic segments”: behold the mighty quadratic asymptote:
B = a·τ² + b·τ + c
L_{asymp} = a·τ² + (b−2·a)·τ + [c−(b−2·a)]
Proof: show ∂L_{asymp}/∂τ = B − L_{asymp}
————– —
integration: over a vertical coordinate, over solid ange Ω, a over the spectrum: I’m guessing that last part may be the hardest. I don’t know how they handle these things in climate models, but I’d guess they use simplifying approximations, eg. – shuffling small bandwidths around by tiny amounts to make the spectra smoother – I read something like that. I imagine parameterizations for some non-PPIA situations (horizontally-patchy, vertically-thick clouds like towering cumulus/cumulonimbus would destroy the PP part)…
Barry E Finchsays
Barton, It turns out some other physicist right here on RC UV also has your bemusement or disagreement re “Not sure what you’re saying here. There is definitely atmospheric back-radiation; we can measure it with instruments”. It’s just down below for you to ponder its physics, asserting “On some …. (physics stuff) some therapy” to sharpen and show your science chops. Alternatively BPL you might prefer not to waste a bit of your life.
Barry E Finchsays
PO27 (No Reply button) I’ve only time to state I didn’t exactly ignore yours of a couple years back but that doesn’t mean that I’ll ever actually find time to study it, or this bit. Still it’s always there (I mean unless the State deletes it all and increases the chocolate ration from 27 milligrammes to 18 milligrammes).
Piotrsays
Barry: “ I mean unless the State deletes it all and increases the chocolate ration from 27 mg to 18 mg.”
I see you are an optimist, Barry. I lived in the State that didn’t see the need to delete it -they would not allow you to post it in the first place. And it increased the chocolate ration, for adults like you, not to 18 mg, but to 0mg/month. So if you really yearned for the taste of chocolate, you would have to trade in your vodka ration for somebody’s kid chocolate ration.
patrick o twentysevensays
Re Barry E Finch – no problem; I wrote for anyone who might be interested. I’ll just emphasize one point: computational costs/resource constraints aside, (I expect) higher resolution (vertical (optically thinner layers), angular (directional), etc.) is generally better.
PS I try not to take it for granted that I am able to often enjoy ~ 300 – 1000 times that amount of chocolate daily.
Nigeljsays
patrick o twentyseven says
“PS I try not to take it for granted that I am able to often enjoy ~ 300 – 1000 times that amount of chocolate daily.”
Yep I would average about that most days. When I gave up smoking chocolate was the substitute strategy. I’m probably a bit addicted to chocolate but its less of a problem than tobacco plus I love the stuff.
Lucky to have the money be able to freely indulge. One should definitely not take these things for granted.
UAH TLT has been posted for November with a global anomaly of +0.43°C, down on Sept & Oct (+0.53°C) and pretty-much back down to the anomalies of the summer. (JJA averaged +0.41°C.)
This drop from October was all southern hemisphere (down to +0.27°C from +0.55°C) with the NH showing an increase (up to +0.59°C from +0.52°C.)
The TLT anomalies have been carving a different path from the SAT through the “bananas!!” period.
Smoothed-out, the global TLT anomalies peaked in March 2024 and have been dropping pretty consistently ever since. The NH ‘plateaued’ rather than peaked and began to drop quite strongly from September 2024 while the SH peaked in March 2024 dropping until Jan 2025 since when it has remained essentially flat. (See this graphed out in the yellow graphics at the foot of the The Banana!!! Watch page
Barry E Finchsays
Surface sends net radiation, sensible & water evaporation-condensing into troposphere. When it’s warmer it sends more of those and I just calculated the increase in water evaporation-condensing equals 0.7 degrees of warmer air if it really has been 9% more H2O gas for the +1.3 degrees and if the energy was used for thermal capacity, warming air, instead of being latent. I’ve no time to ponder whether or not that means anything about the TLT change vs surface temperature change (the surface is solid or liquid but the measurement is made nominally 2m above the surface so perhaps I’ve noted nothing of interest).
One Anonymous Blokesays
Been a long time since I commented here. Thanks for the continued efforts you all put in. I can’t find the answer to a question that occurred to me lately and I’d be very grateful if someone could point me in the right direction:
If Hansen is right and climate sensitivity is higher than IPCC puts it, leading to the acceleration he posits, does that mean that reductions in atmospheric GHGs would reduce temperature faster than current modelling?
Thanks in advance if anyone cares to help me out.
zebrasays
Good question. It depends on how complicated an answer you want.
A few comments back, Paul P posted this reference, which I found very useful:
So one could answer you by saying “you gotta do the math”.
But I think you have to be clear about your question. Do you mean reducing CO2 after it is already added, or reducing the future value by reducing emissions now?
For example, if you have already melted all the ice on the planet and then you figure out a magic way to draw down CO2, you would have to create completely new models.
One Anonymous Blokesays
“Do you mean reducing CO2 after it is already added, or reducing the future value by reducing emissions now?”
Thanks for responding. I mean “reducing CO2 after it is already added”, although obviously the latter scenario would be preferable..
Tomáš Kaliszsays
in Re to One Anonymous Bloke, 6 Dec 2025 at 11:36 AM,
In the following discussion, he explained that these publications bring evidence that while global mean surface temperature (GMST) rise will likely stop a few decades after the “net zero” in emissions of non-condensing greenhouse gases (GHG) is reached, the Earth energy imbalance (EEI) will stay positive and the sea level rise (SLR) will continue for millennia.
A closer look suggests that there is a spread across climate models tested – some may show a longer continuing temperature rise after the “net zero”, some an almost instant temperature decline.
It is likely a result of different rates of two counteracting processes that decide about the outcome in each individual model – the natural CO2 drawdown from the atmosphere (that decides about the decline of Earth energy imbalance (EEI)) on one hand, and proportionality of the GMST change to the EEI (which may be, in my understanding, closely related to the climate sensitivity) on the other hand.
If so, I think that it may be well possible that if the “hot” models indeed apply for the present Earth climate, the “zero emission commitment” (ZEC) can be higher than that should be expected in case that the climate sensitivity is moderate.
As a layman, I will, however, definitely appreciate a comment (and, possibly, a correction) from someone more skilled in the art of climate science.
Best regards
Tomáš
One Anonymous Blokesays
Thanks for that reply Tomáš.
My question is more about any removal of CO2 (in the event that a mechanism could be invented to do this) than ‘net zero’, and the difference (if any) between what the IPCC might predict vs. Hansen’s higher climate sensitivity.
Does a higher climate sensitivity imply that changes resulting from a (purely theoretical) reduction in CO2 would happen faster?
I just found this link from 2008, wherein Hansen et al mention “a possibility of seeding irreversible catastrophic effects.” So perhaps the answer to my question is “probably not”.
I see these categories under “Our Work”
-Climate Research
-Climate Data
-Public Awareness & Policy Solutions
–Our Children’s Trust
–Citizen’s Climate Lobby
–350.org
One Anonymous Blokesays
Thanks very much for that, Neurodivergent, I’ve subscribed to JH’s substack.
zebrasays
OAB,
Yes. And it doesn’t really have to be a “catastrophic” change like my example of all the ice melting; it’s a matter of the system becoming “different enough” from what we are working with now.
That’s the real question with the whole “acceleration” discussion. The temperature (GMST) is one of many characteristic of the system that respond to the increase in total system energy caused by CO2.
But the current models may not be able to predict a future GMST if, for example, the AMOC slows down to some arbitrary level. That’s the nature of complex systems as discussed in the reference I gave. They are complex; you have to do the math.
One Anonymous Blokesays
Thanks Zebra. “The temperature (GMST) is one of many characteristic of the system”
An insight I hadn’t considered let alone appreciated.
Barry E Finchsays
I’ll point out 1 quick thing for now which is “Pattern Effect”. If it’s real then it’s unstoppable because it’s a Done Deal. Assessed at =0.8 degrees over a few hundred years it requires no Forcing because it’s only that the ocean redistributes heat already in it and asserted it’ll reduce low cloud cover (over eastern tropical Pacific I think I recall but check that yourself). At https://www.youtube.com/watch?v=jlolDdnSHCE
Piotrsays
Re: One Anonymous Bloke
In a vague, i.e. inconsequential sense – probably yes, but the real question whether it will be significant/comparable to the Hansen acceleration.
Your question seems to anticipate symmetry – but there is no reason to expect one – Hansen’s higher sensitivity requires strong positive feedbacks and/or crossing tippings points. And different feedback have different mechanism and thus different strengths and inertias. For example, you can start reducing CO2 conc., but the ice would be still melting with lower albedo countering the cooling expected from dropping CO2.
And to see why we should not expect symmetry – see the glacial-interglacial sequences:
they are triggered by the orbital cycles, but they cause negligible differences in the avg. solar radiation Earth’s receives (its all about heating in Arctic in summer, even if it’s globally balanced by cooling elsewhere or winter), so the massive difference in GMST between Ice max and T max – is almost exclusively thanks to the four positive feedbacks: ice albedo-T, water cycle-T, CO2-T and CH4-T, each different in strengths, geographic patterns, inertia etc.) and likely different responses on the way up as on the way down. Not surprisingly deglaciation phase is MANY times shorter than the glaciation phase.
So if even a symmetrical signal (orbital cycles) is not a guarantee of a symmetrical outcome (glacial-interglacial sequences), then what expect when even the signal (here: atm. Co2 changes) is not likely to be symmetrical?
So the only way to evaluate is to run the models. With the “current-modelling” from what I heard on RC (M.Mann?) – the net-zero human emissions CO2 – by allowing natural sinks to REDUCE atm. CO2 –
could ~ STABILIZE GMST. So obviously no symmetry there.
And the “IPCC” models are not as dependent on the positive feedbacks as is Hansen – so asymmetry in Hansen would likely be more pronounced.
And that’s not even talking about tipping points, which importance is tied SOLELY to their asymmetry
(if they were symmetrical, thus easily reversible – they wouldn’t be tipping points).
So the answer to your question is either trivial (“probably yes”), or non-answer (“we don’t know whether it will be significant or not”).
Given that, a more interesting question is – why do you ask? ;-)
One Anonymous Blokesays
Thanks for that detailed response Piotr. Your remarks about asymmetry are especially helpful. As to why I asked the question, it’s partly curiosity and partly to avoid a mistaken sense of optimism.
Susan Andersonsays
This is an interesting review of what’s wrong with AI ‘science” and how publication and peer review are being corrupted: Artificial intelligence research has a slop problem, academics say: ‘It’s a mess’. AI research in question as author claims to have written over 100 papers on AI that one expert calls a ‘disaster’ – https://www.theguardian.com/technology/2025/dec/06/ai-research-papers [I’m going to try to use blockquote for the following but if it doesn’t work, please know that the following is all quote:}
similar cases among AI researchers, who said their newly popular discipline faces a deluge of low-quality research papers, fueled by academic pressures and, in some cases, AI tools.
…. “team endeavors” run by his company, Algoverse. The company charges $3,325 to high-school students and undergraduates for a selective 12-week online mentoring experience – which involves help submitting work to conferences.
….
Meanwhile, students and academics are facing mounting pressure to rack up publications and keep up with their peers. It is uncommon to produce a double-digit number – much less triple – of high quality academic computer science papers in a year, academics said. Farid says that at times, his students have “vibe coded” papers to up their publication counts. | “So many young people want to get into AI. There’s a frenzy right now,” …. “It’s just a mess. You can’t keep up, you can’t publish, you can’t do good work, you can’t be thoughtful,” he said.
…. “You have no chance, no chance as an average reader to try to understand what is going on in the scientific literature. Your signal-to-noise ratio is basically one. I can barely go to these conferences and figure out what the hell is going on.” | “What I tell students is that, if what you’re trying to optimize publishing papers, you know, it’s actually honestly not that hard to do. Just do really crappy low-quality work and bomb conferences with it. But if you want to do really thoughtful, careful work, you’re at a disadvantage because you’re effectively unilaterally disarmed,” he said.
“average reader to try to understand what is going on in the scientific literature”
I think many researchers are sensitive to this situation. The year 2020 marked early usage of LLM and by 2o21 there was more widespread adoption. My own research findings, which I assune can be misconstrued as LLM-assisted, all happened prior to 2019 and I haven’t published anything since. Not that I did this intentionally, but as time goes by, I’d like to maintain the focus on the original published work to avoid the appearance of it being tainted by LLM vibe content.
Perhaps there will be a demarcation of B.C. – “Before ChatGPT”, and A.D. – “Anno Discursio” to indicate when a work was formulated or published.
Susan Andersonsays
Oops: after saying I’d try blockquote I failed to do so. It’s still all quote, fwiw. A valuable article on the problem with publishing and peer review today. The lies have it!
Susan Andersonsays
Just Have a Think (Dave Borlace) is turning the heat up a notch (as the actual heat continues to increase): New analysis. How corporate overlords are unlawfully ignoring future climate impacts. – https://www.youtube.com/watch?v=YtS0j4hXCAs
“Fiduciary Duty is a phrase often touted by corporate CEOs and Wall Street types to justify their dodgy deals and questionable board level decisions. But Fiduciary Duty also involves safeguarding the LONG-TERM security of shareholders investments. Now a group of expert lawyers has published a report outlining how Exec Boards and Fund Managers are acting unlawfully if they do not fully factor in the impacts of the climate emergency. And the findings are quite challenging.”
Davidsays
Susan, good stuff, thanks. Unfortunately, with Pres. Trump’s plans for the next SEC head and his upcoming pick for Federal Reserve head to replace Powell next year beginning to leak, it looks pretty clear that climate change and corporate governance policies are going bye-bye until the Democratic Party can retake the White House.
C.C. Side Topic — A bright sign I think I can see is with the U.S. Supreme’s having repeatedly expanded the reach of the Executive Branch, there is going to be an opportunity for the D’s to do some real things, that if done right, could create positive changes (including on AGW) for the swathes of America being stepped on now in Gilded Age II.
I watched the following YouTube yesterday that (conveniently) does a reasonable job of outlining my philosophy on the subject. It’s an conversation with Marc Dunkelman hosted by John Avalon (39min). If you Susan, or anyone, does have time to watch it one of these days, weeks or months ahead, I’d love to hear it:
David, why would climate change and corporate governance policies go bye-bye when we have many Democrat-run states?
Interesting video. They point out over and over that the reason Dems never get anything done on environmental or other “progressive” projects is too much government red tape, over-regulation, threat of lawsuits, excessive permit requirements, and all the things that Dems love and that Republicans have said for decades need to be reduced. They even say that Reagan’s ideas would benefit us – get government out of the way. They said that every time an environmental or progressive project comes up, out come the “progressive” NIMBYs to stop it.
After pointing out for a half hour all of the Democrat policies that prevent environmental and/or “progressive” projects to be built, they trot out their possible DEMOCRAT presidential candidates! So, they think the same group causing total dysfunction in government is going to somehow, magically, all of the sudden become competent and start successfully building things. Hilarious.
Then they insult Trump (the guy with bad hair in the WH) – the man who, more than any other in government, has a proven track record of successfully building large projects, and in the past 10 months working tirelessly to Make America Great Again.. He’s famous for fixing in 4 months what Democrats in NYC government couldn’t fix in many years:
Then, to top it all off, at 36:48, the 2 Democrats say they want to Make America Great Again. BWAHAHAHA!
Every day in the newspapers of blue holes across the nation, are articles about how the Democrats running the blue holes are going to fix public schools so the kids can read and write, make housing affordable, fix the homeless problem, fix traffic congestion, reduce crime, and on and on. Every year, in the same newspapers it is reported how all of the above and more are WORSE than the year before and they print the promises of the Democrat mayor, governor and city council members to make the problems better in the new year. It never happens – it just gets worse. -year after year for DECADES. Every election, all the voters in the blue holes STAMP THE DONKEY, and wonder why their blue hole continues to decline. You know the old saying about doing the same thing over and over and expecting different results……
Neurodivergentsays
The place is a joke. Neither side of US politics offers anything tangible rational or sane. Trump is a 21st century Mussolini fascist – and idiot in power with bullying thugs lording it over the rest
James Carvill throws his imprimatur into the ring. Comment by Peter Turchin
More recently, his tone has changed. In the latest essay, Out With Woke. In With Rage (Nov. 24, 2025), he has started to formulate a positive program for the Democrats:
JC (by nature?)
” I am now an 81-year-old man and I know that in the minds of many, I carry the torch from a so-called centrist political era. Yet it is abundantly clear even to me that the Democratic Party must now run on the most populist economic platform since the Great Depression.”
This is a big shift and it reflects the revolutionary times we live in. As I wrote in End Times, the Democratic Party did a great job suppressing its populist wing. This contributed to the defeat of its presidential candidates in both 2016 and 2024. What Carville calls “centrist,” actually, means “conducting policies for and by the ruling class.” Now that it has been overthrown, the
Democratic Party is ripe for the takeover by the left-wing populists (just like the Republican Part may be in the process of being taken over by the right-wing populists). And that’s what Carville essentially proposes.
Carville’s piece reads a lot like my posts in the series A Chronicle of Revolution. I doubt he read it; most likely, it’s starting to dawn on the former ruling party that “centrism” is dead. A few quotes:
“The people are revolting, and they have been for some time.”
“the rigged, screwed-up, morally bankrupt system”
“If you’re a student of history, the French Revolution is in the American wind.”
Harvard tracks the youth voice
the mainstream media and political parties are viewed more as threats than assets.
many indicators pointing to widespread financial, emotional, and social strain.
expecting fewer opportunities, greater threats to job security, and diminished meaning in their careers.
Social trust is unraveling, as many young Americans avoid political conversations, fear judgment for sharing their views, and doubt that people with opposing perspectives want what’s best for the country.
reveals a generation under profound strain, as young Americans report deep economic insecurity, eroding trust in democratic institutions, and growing social fragmentation. https://iop.harvard.edu/youth-poll/51st-edition-fall-2025
Pathological Self-Interest and Greed Rules America – a republic in name only
Thomas W Fullersays
Mr. Know it All, I’m curious–do you actually believe what you wrote in this comment?
Mr. Know It Allsays
Thomas,
Yes, my comment is factual, much of it just repeating what the 2 guys in David’s video said about why Dems can’t get anything done. BPL below said that Dems were able to get things done in 1948. Probably true – the party hadn’t gone totally off the deep end at that time. They at least knew the difference between a male and female – that’s a low bar, but today they fail even that basic test, and that is a sad commentary. The consequences of such incompetence are catastrophic and we’re seeing them every single day and it will likely get worse before it gets better.
Was there something in particular that you thought I might not actually believe?
On Neurodivergent’s comment about young American’s economic insecurity, I wonder how much their poor education today in public schools (and in college) is contributing to that? If they’ve gone into debt to get useless degrees in various “studies”, and been indoctrinated into nonsense, can’t do the math to make change at a cash register, have mental breakdowns whenever someone expresses a viewpoint they don’t like, and basically learned little to nothing of value in public schools or in college, then I’d expect them to have a hard time economically.
Neurodivergent says they are also experiencing “eroding trust in democratic institutions”. I’d expect that when the Democrat party will not allow basic election security measures to be put in place. It isn’t just young folks who don’t trust our elections – most don’t – and it could be fixed, but just as with “progressive environmental projects”, Democrats will not allow it to be fixed. We know why.
Barton Paul Levensonsays
KIA: BPL below said that Dems were able to get things done in 1948.
BPL: I don’t remember saying that. I think that was someone else.
Barton Paul Levensonsays
KIA: They at least knew the difference between a male and female – that’s a low bar, but today they fail even that basic test, and that is a sad commentary.
BPL: What do you guys have against transsexuals? Do you know any? I do. I have a good friend who is trans (male=>female). She’s a nice, clever, friendly person and I value her friendship. She isn’t a threat to anybody.
Lay off the hate. It’s very off-putting.
Barton Paul Levensonsays
KIA: the reason Dems never get anything done on environmental or other “progressive” projects is too much government red tape, over-regulation, threat of lawsuits, excessive permit requirements, and all the things that Dems love and that Republicans have said for decades need to be reduced.
BPL: We got a lot done. We no longer have pollution emergencies like Donora, PA in 1948. Rivers no longer catch on fire. We got lead out of gasoline. My home town of Pittsburgh no longer has a coating of soot all over the buildings and cars each morning. So your starting point is counterfactual.
Tomáš Kaliszsays
In Re to Barton Paul Levenson, 14 Dec 2025 at 9:21 AM,
Copernicus has posted ERA5 SAT for November confirming the Nov anomaly at +0.65°C. This continues the marked increase in anomaly through Sept-Nov averaging +0.67°C. The unusually warm SH seen in both Sept & Oct (driven by particularly unusual Antractic anomalies) faded through Nov with the NH showing some of its normal Autumn upward wobble. (By way of comparison. through the Summer, Jun-Aug globally averaged +0.47°C.)
With that Sep-Nov upward wobble, the 2025 Jan-Nov average is now effectively identical to the 2023 Jan-Dec annual average. Which year has the edge depends on which anomaly base you choose. (Using 1850-1900, 2023=+1.481°C, 2025-to-date=+1.477°C, using 1991-2020, 2023=+0.6008°C, 2025-to-date=+0.6013°C.) So a December average of more than +0.60°C would put 2025 as the 2nd warmest year on record. The first seven days of December are showing an average of +0.54°C. But it’s early days.
Neurodivergentsays
Contrary to what you were intimating in late 2024 and early mid 2025, is this a quite understated acknowledgment that your expectations were completely wrong?
I hope so.
Also I can safely conclude now that it’s is also an additional acknowledgement that you’re seeing Jim Hansen as being correct in his expectations what would support (or not support) his general theory culminating in his last 3 published papers ….. about the 2023-2024 massive spike in global temperatures.
quoting
The Acid Test: Global Temperature in 2025
James Hansen and Pushker Kharecha 20 February 2025
The unprecedented leap of global temperature in 2023 and early 2024 exceeded 0.4°C (Fig. 1). We
and coauthors2 interpret that uniquely large warming as being due about equally to a moderate El
Nino and reduction of ship aerosols, with a smaller contribution from the present solar maximum
(our entire paper, including Abstract & Supplementary Material is available in a single compressed
PDF here). An “acid” test of our interpretation will be provided by the 2025 global temperature:
unlike the 1997-98 and 2015-16 El Ninos, which were followed by global cooling of more than
0.3°C and 0.2°C, respectively, we expect global temperature in 2025 to remain near or above the
1.5°C level. Indeed, the 2025 might even set a new record despite the present weak La Nina. There
are two independent reasons. First, the “new” climate forcing due to reduction of sulfate aerosols
over the ocean remains in place, and, second, high climate sensitivity (~4.5°C for doubled CO2)
implies that the warming from recently added forcings is still growing significantly. https://www.columbia.edu/~jeh1/mailings/2025/Acid.Test.20Feb2025.pdf
And this one here too
2025 Global Temperature
James Hansen and Pushker Kharecha 15 April 2025
Abstract.
Global temperature for 2025 should decline little, if at all, from the record 2024 level.
Absence of a large temperature decline after the huge El Nino-spurred temperature increase in
2023-24 will provide further confirmation that IPCC’s best estimates for climate sensitivity and
aerosol climate forcing were both underestimates. Specifically, 2025 global temperature should
remain near or above +1.5C relative to 1880-1920, and, if the tropics remain ENSO-neutral,
there is good chance that 2025 may even exceed the 2024 record high global temperature https://www.columbia.edu/~jeh1/mailings/2025/2025GlobalTemperature.15April2025.pdf
Barry E Finch, Piotr and Atomsk’s Sanakan must be feeling gutted and embarrassed about their anti-Hansen anti-peer reviewed science trolling all over again.
MA Rodgersays
Neurodivergent (or whoever you are),
I don’t know what it is you think was “intimating in late 2024 and early mid 2025,” but I am not aware of any volte-face in my understanding of the cause of the 2023-24 “bananas!!” temperatures.
Hansen acolytes such as yourself should consider the dropping temperature anomalies through 2025 and see that they do not suggest the “bananas!!” resulted from positive forcings resulting from the 2020 marine pollution regs. And I was always of the opinion that such forcings could not be made to fit the evidential basis of the “bananas!!”
Hansen did hedge his bets in a paper this year insisting the “bananas!!” (or perhaps it was the post-2010 acceleration generally) could be due to reducing aerosols but could also be due to the appearance of cloud feedbacks. He argued that both would have the same implications for ECS. Feedbacks can disappear when the initiating forcing or temperature wobble is remove so cloud feedbacks remain on the table. But the aerosol forcing idea is dead.
As for Hansen’s “acid test”, my reading has always been that when Hansen & Kharecha said “we expect global temperature in 2025 to remain near or above the 1.5°C level.” this concerned monthly anomalies. If it did not, their follow-on statement “Indeed, the 2025 might even set a new record despite the present weak La Nina” doesn’t make a lot of sense.
2025 monthly temperatures didn’t remain near to +1.5ºC (dropping to +1.25ºC for July) and the 2025 annual anomaly has never looked like threatening to best 2024’s +1.6ºC.
All we have is 2023 with a “bananas!!” end to the year and 2025 with a “bananas!!” beginning vying for the 2nd place. Likely they will be =2nd.
Re: “Barry E Finch, Piotr and Atomsk’s Sanakan must be feeling gutted and embarrassed about their anti-Hansen anti-peer reviewed science trolling all over again.“
That’s nice, Mo Yunus, a.k.a. several other sockpuppet accounts. You’ve implicitly confirmed I was right about you. Regardless of how many sockpuppet accounts you use, you revert to your usual tactics, like idolizing Dr. James Hansen to the point that you angrily misrepresent even mildcriticism of what he says.
Let me know when you can cogently address the actual criticisms of what Hansen said. I won’t hold my breath, though, since that would require you replacing your idol worship with the integrity and intellect needed to grasp topics like statistical tests for acceleration, selection bias, etc. You’ve never managed that across your several accounts.
Re: “[“]An “acid” test of our interpretation will be provided by the 2025 global temperature: unlike the 1997-98 and 2015-16 El Ninos, which were followed by global cooling of more than 0.3°C and 0.2°C, respectively, we expect global temperature in 2025 to remain near or above the 1.5°C level. Indeed, the 2025 might even set a new record despite the present weak La Nina.[“] […] Hansen get’s it right yet again. […] Barry E Finch, Piotr and Atomsk’s Sanakan must be feeling gutted and embarrassed about their anti-Hansen anti-peer reviewed science trolling all over again.“
The temperaturedrop from 2024 to 2025 is at least as large as the global surface temperature drop from 2016 to 2017. Similarly, the difference between the 2023/2024 average vs. 2025 is at least as negative as the difference between the 2015/2016 average vs. 2017. So no, 2025 did not set another record, nor is its temperature drop from 2023/2024 so small as to make 2023/2024 appear starkly “unlike the 1997-98 and 2015-16 El Ninos.”
Moreover, my criticisms of Hansen’s claims have not been about the global temperature anomaly for 2025 vs. for 2023/2024. My criticisms are instead about him using statistically unsound methods to claim acceleration of global surface warming, when statistically sound methods instead do not show statistically significant warming. I also previously noted that Barry E Finch gave a warming trend comparable to what your fellow Hansen idolizer Geoff Miell cited from Hansen:
– Barry E Finch says: “The multi-decadal warming trend right now is substantially <+0.36 / decade, more like +0.29 / decade.”
You quoting Hansen on 2025 vs. 2023/2024 does not rebut Barry E Finch’s point on the multi-decadal warming trend, nor does it rebut my point on statistically significant acceleration. Like so many of Hansen’s fans, you don’t get the difference between shorter-term fluctuations vs. longer-term trends that are more statistically robust. And/or this great illustration of how you willfully misrepresent criticism of Hansen’s claims.
So 5 questions for you, Neurodivergent:
1) Is the global surface temperature decrease from 2024 to 2025 at least as large as the decrease from 2016 to 2017?
2) Is the global surface temperature difference between the 2023/2024 average vs. 2025 at least as negative as the difference between the 2015/2016 average vs. 2017?
3) Based on the answers to question #1 and #2, is this prediction wrong?:
“[…] unlike the 1997-98 and 2015-16 El Ninos, which were followed by global cooling of more than 0.3°C and 0.2°C, respectively, we expect global temperature in 2025 to remain near or above the 1.5°C level. Indeed, the 2025 might even set a new record despite the present weak La Nina.”
4) Did Hansen give a global surface warming trend of 0.30°C/decade that’s similar to Barry E Finch’s trend of “substantially <+0.36 / decade, more like +0.29 / decade“?
5) Did you citing Hansen comparing 2025 to 2023/2024 do nothing to rebut my criticism that Hansen has not shown statistically significant acceleration of global warming (i.e. a statistically significant changepoint) from some point in the 1990s, 2000s, or 2010s?
The answers to these questions are:
1) Yes
2) Yes
3) Yes
4) Yes
5) Yes
I predict you will not honestly address those questions, much like Geoff Miell repeatedly avoidedpertinentquestions:
– Nigelj says: “AS asked simple yes no questions and perfectly reasonable questions. Geoff Mielle responded like a slippery, evasive politician. For whatever reason.”
– David says: “Geoff, you asked for inputs. I’ll start like this. Please provide specific answers to the five questions AS has asked of you as shown below”
Piotrsays
Atomsk: “ Barry E Finch gave a warming trend comparable to what your fellow Hansen idolizer Geoff Miell cited from Hansen
I am not sure they actually “idolize Hansen” – they USE Hansen for their overriding psychological need – to prop up their ego by association with Hansen intellectual and ethical authority: if I, [Multitroll, Geoff Miell, etc …), without much climate science background, can see (in Hansen) what top climate scientists can’t or refuse to see, then I must be very, very, smart and virtuous .
So they use Hansen as a drunkard would use a police-grade heavy flashlight – not for enlightenment, but to bash opponents head.
Yeah, Piotr. It’s rather sad. It’s the same petty behavior Neurodivergent showed when posting under their Lleim sockpuppet account:
”They hate Hansen with a vengeance. A combination of jealousy adhd and bitterness.
You should pause and note that you will never get any support or agreement here from anyone no matter how accurate your material is, especially from those holding very old phd degrees.”
It’s gotten to the point that they don’t even see the implications of what Hansen is saying, as I illustrated with my 4th question. And as I said elsewhere, I think a lot of this is driven by misinformation from people like Leon Simons.
Re: “My criticisms are instead about him using statistically unsound methods to claim acceleration of global surface warming, when statistically sound methods instead do not show statistically significant warming.”
I mistakenly left out a word. That should instead read:
‘My criticisms are instead about him using statistically unsound methods to claim acceleration of global surface warming, when statistically sound methods instead do not show statistically significant warming acceleration.’
Re: “And/or this great illustration of how you willfully misrepresent criticism of Hansen’s claims.”
I mistakenly left out two words. That should instead read:
‘And/or this is a great illustration of how you willfully misrepresent criticism of Hansen’s claims.’
Atomsk’s Sanakan,
To be fair, I think the answer to your question 1) is “No, not yet.” Hansen’s ‘Acid test’ only makes sense if it refers to something other than annual temperatures.. The quote “the 1997-98 and 2015-16 El Ninos, which were followed by global cooling of more than 0.3°C and 0.2°C” likely refers to the rolling 12=month values plotted-out by the blue trace in the graphic at the top of the Hansen & Kharecha posting linked above. The numbers used look like GISTEMP so the rolling 12-month peak and troughs (with end of period dates) would be:-
1998 … 8 .. +0.65°C
2000 … 2 .. +0.36°C Cooling … 0.30°C
2016 … 9 .. +1.07°C
2018 … 4 .. +0.85°C Cooling … 0.22°C
2024 … 8 .. +1.32°C
2025 … 11 .. +1.21°C (latest) Cooling … 0.11°C so far
The problem with Hansen’s ‘Acid test’ is that it wasn’t explained very sharply. The general idea that the 2023/24 El Niño was not the entire driving force behind the “bananas!!” is likely true. However, Hansen’s ‘Acid test’ was going a step further by saying 2025 would see no cooling relative to 2024 (and could even see further warming), this predicated on the view that the extra ingredient was a forcing which would continue its work after the 2023/24 El Niño had come and gone. That ‘forcing’ explanation appears to be wrong.
Nigeljsays
MAR, I wonder if Hansen is half right: The year 2025 is indeed cooler than 2024 but you would expect this as the planet is moving out of el nino and into a la nina since September, But 2025 is still at least moderately warmer than what the climate community was expecting previous to 2023 isnt it? Therefore there may be some forcing continuing its work.
Jimsays
MA Rodger says
Hansen’s ‘Acid test’ only makes sense if it refers to something other than annual temperatures..
The problem with Hansen’s ‘Acid test’ is that it wasn’t explained very sharply.
That ‘forcing’ explanation appears to be wrong.
These flawed conclusions and allegations against Hansen’s acid test explanations must only apply to people who do not understand the simplicity of the information presented by Hansen.
Likely coupled with their inability or outright refusal to contact the author direct and seek his personal edification on their confusions.
The ignorant with too much to say, throwing sand in the eyes of genuine truth seekers, remains their own problem. Not Hansen’s.
Re: “Atomsk’s Sanakan,
To be fair, I think the answer to your question 1) is “No, not yet.” Hansen’s ‘Acid test’ only makes sense if it refers to something other than annual temperatures.“
Thanks for pointing that out. If the test is interpreted as annual values for the two El Niño years, then enough time has passed to assess it. But it has the problems noted in my comment. If it’s instead interpreted in the way you suggest, then the Neurodivergent sockpuppet account was wrong when they said: “Hansen get’s it right yet again“. After all, the sockpuppet didn’t wait long enough after 2024 to know they’ve reached a trough, or at least long enough to match the wait time after 1998 and after 2016, as shown in your comment.
So they’re wrong either way. I probably shouldn’t have given them the benefit of the doubt by interpreting Hansen’s statements to fit with their assumption that enough time had passed to assess Hansen’s statements.
Barry E Finchsays
MAR My 1-minute 5-cents analysis worth. I still suggest strongly that Matthew H. England et al 2 papers about ocean surface winds (entirely different) have been significant over (1) 1996-2015 increasingly, not a step-change (2) 2023 the period covered by Matthew H. England et al 2nd Paper I refer to.
(1) Quote: “The record-breaking increase in Pacific Equatorial trade winds over the past 20 years had, until now, baffled researchers”. “When it does end, they expect to see some rapid changes, including a sudden acceleration of global average surface temperatures … It will be difficult to predict when the Pacific cooling trend and its contribution to the global hiatus in surface temperatures will come to an end,” Professor England says.”
“Recent intensification of wind-driven circulation in the Pacific and the ongoing warming hiatus” Matthew H. England, Shayne McGregor, Paul Spence, Gerald A. Meehl, Axel Timmermann, Wenju Cai, Alex Sen Gupta, Michael J. McPhaden, Ariaan Purich & Agus Santoso Nature Climate Change 4, 222–227 (2014) doi:10.1038/nclimate2106 Received 11 September 2013 Accepted 18 December 2013 Published online 09 February 2014 Corrected online 14 February 2014
My +0.065 degrees increase at 2014 by rotating 1995-2014 estimate I measured a couple months ago over 30 minutes from the pictorial at 21:38 at https://www.youtube.com/watch?v=agKayS6h6xA (I’ve been tracing various screen plots since 2013, zoomed up on 8×11 or 11×22 paper, GMST plots, Arctic Ocean albedos, ice loss, etc.) mid-east Pacific 60S-60N cooled average 0.20 degrees while GMST NOAA rose 0.30 degrees and 0.50 * 13% of Earth surface area I measured = +0.065 degrees GMST for a 20-year Unnatural Variation caused by humans warming the Atlantic faster than Pacific which imbalance caused Atlantic easterly surface winds to drive Pacific easterly surface winds faster than they been for at least the last 130 years (the reliable record length is what I understand). I assume that Atlantic wind effect on Pacific easterly surface winds has been diminishing or has stopped.
Re: “Likely coupled with their inability or outright refusal to contact the author direct and seek his personal edification on their confusions.“
That’s nice, sockpuppet account. Jim, you again give yourself away with your Hansen idolization. If you’d ever written a paper before, then you’d know the paper is supposed to be self-contained, such that it includes all the information needed to interpret it without needing to contact the authors. If Hansen and his co-authors did not include that level of detail, then that’s their fault, not the fault of the reader. Contacting the authors is supposed to be for things like requesting raw data, inquiring about collaborating, etc. It’s not supposed to be a get-out-of-jail-free card for the authors to write their paper in an ambiguous or unclear manner.
Re: “These flawed conclusions and allegations against Hansen’s acid test explanations must only apply to people who do not understand the simplicity of the information presented by Hansen.“
Then give an explanation of that information instead of just posturing. Given an interpretation of what Neurodivergent quoted from Hansen that:
1) matches what Hansen said
2) has enough time pass to assess whether Hansen is right
3) confirms Hansen is right
Conditions 2 and 3 are from your sockpuppet account Neurodivergent saying: “Hansen get’s it right yet again“. I gave an interpretation that met condition 2, arguably condition 1, but contradicted condition 3. MA Rodger gave an interpretation that met condition 1, but contradicted conditions 2 and 3. My point is that there is no plausible interpretation that meets all three conditions, thereby debunking what Neurodivergent said. And given your track record of evidence-free evasive posturing across your sockpuppet accounts, you’re not going to give an interpretation that meets all three conditions.
Barry E Finch,
I recall that you have raise this ‘wind-driven-circulation’ thing before and specifically cited England et al (2014). At publication, England et al were setting out a potential cause of that slowdown in AGW which was exercising everybody back then.
Matthew England is well-published but I don’t see any updates that reinforce the findings of England et al (2014). Note he is a co-author of Li et al (2022) ‘Recent acceleration in global ocean heat accumulation by mode and intermediate waters’. (‘Mode’ isn’t a particularly well-known term here. It does have a Wiki page – Mode Water.) Li et al conclude by saying:-
Our work reveals accelerated warming in the upper 2000 m of the ocean over the past several decades and highlights increasing heat uptake by mode and intermediate waters, with these two water masses responsible for the majority of ocean warming over the Argo era (2005–2020), despite a limited area of interaction with the atmosphere. Exactly how this heat uptake plays out over the coming decades and beyond remains highly uncertain. For example, climate change-induced warming and freshening at the surface are projected to stratify the upper ocean, which will reduce the overturning of these water masses, in turn reducing their capacity to uptake heat. This would have profound implications for the rate of future anthropogenic climate change.
The rate of GMST increase under AGW will be greatly dependent on ocean warming and mechanisms therein. Famously, El Niño’s are an example of this dependence leading to the large ENSO wobble. And there may have been a different but similar/associated outpouring of ocean heat that resulted in the “bananas!!”. Myself, I did start a search for signs of it but didn’t get very far.
It is now a couple of years since the “absolutely gobsmackingly bananas!!” proclamation but as yet no published papers that I have seen pointing strongly in the direction of ocean heat being the cause, even from Matthew England, although there may be something hiding away in his long publication list. (For the record, I didn’t see England et al (2025) as providing the long-term wobble that would fit the “bananas!!”.)
Matthew England may perhaps be saying some eye-opening stuff in that hour-long YouTube you link-to, but sadly I’ve presently not the time/inclination to be searching through it without more to go on.
Piotrsays
Jim: ” Common Sense dictates that Atomsk’s Sanakan, Piotr, and Rodger will unlikely be cured of their difficulties here.”
Quite a statement from somebody who just arrived on this group ;-)
If it walks like a Yebo, quacks like a Neurodivergent, swims like a Pedro and poops in public places like a Dharma, then it is a Jim.
And Atomsk simple questions still await – changing your face won’t change anything in that.
More info on mode water, which is imp0rtant in stratification and metastability, consider in lakes —
Autumn: As the surface cools, the epilimnion (a mode water layer) deepens. Eventually, the entire lake cools to ~4°C, triggering the autumn overturn. After overturn, the whole lake becomes, temporarily, one large mass of mode water (isothermal).
Winter: In ice-covered lakes, inverse stratification may set in.
Spring: After ice-off, the surface warms to 4°C, triggering spring overturn. As warming continues, wind mixing creates a new, warm mode water layer at the surface (the new epilimnion), re-establishing summer stratification.
So overturning is the reset button that mixes the whole lake. Mode water is the uniform slab of water that is either a major part of a stratified lake or the entire lake just after the reset.
Wish that oceans were this predictable in overturning, which is complicated by salinity, Coriolis, and the obvious strong tidal forcing effects — exaggerated immensely by density differences in stratification!, which are further incommensurate with seasonal cycles, thus creating an erratic pattern.
Piotrsays
MARodger “ to Matthew England may perhaps be saying some eye-opening stuff in that hour-long YouTube you link-to, but sadly I’ve presently not the time/inclination to be searching through it without more to go on”
I share your sentiment. And I would like to expand it in a more general comment to improve the effectiveness of discussion here and elsewhere:
a link to a video does not prove your point. Yes, it is OK to give a link to Youtube video for people looking for a general explanation of some question they have little familiarity with – but for specific technical argument – a link to 1hr+ long video is a non-starter – I would have to waste an hour of my life to listen to a talk covering things that I likely already know to get to the promised morsel of insight hidden somewhere there.
The proof of showing how a video clip supports one’s specific argument lies on the proponent – you have to point to the minute where the referenced video covers your point – after all you must have watched this video and it is your, not my, argument.
Particularly that too often (and I am NOT saying this about you, Barry) it is a Hail-Mary pass by the deniers and Multi-trolls, who having failed to defend their point – throw in link to a video, as if all the vindication of their position they needed was there.
And a link to a you-tube is not at all like a link to a paper – that – unlike a youtube link, has been peer-reviewed and I can quickly look at the abstract, graphs and conclusions before deciding whether is was worth my time or not.
Pete Bestsays
They all understate here but such is the nature of scientific blogs and they are harsh too on others.
Nigeljsays
Pete Best,
“They all understate here”
If you wish to claim people understate the climate problem, you have to provide some specific evidence they are doing this. For example MAR and AS are both obviously warmists, but have posted lengthy comments sceptical of some of the more extreme claims made on the climate issue.
Where exactly do you think they are getting it wrong? Please understand just quoting someone who thinks climate change will be at the extreme end or whatever, is not adequate. You have to show in detail where MARs and AS’s specific claims and reasoning are wrong.
Personally, I think climate change could potentially be towards the upper level of estimates but I’ve seen some really extreme claims that simply lack credibility. Not an expert myself but some of this stuff is still just obviously very speculative and isn’t thought through.
Pete Best’s comments are just the usual substance-free tone trolling. One way to deal with that sort of person is to ask them pertinent questions, give them sufficient information to answer the questions, and then see whether they address the questions. Trolls expose themselves by not honestly and cogently engaging with the questions. Typically they just bravely run away.
I’ve asked the questions in this comment above. So I’ll leave it to the trolls to expose themselves, as the geologist and science journalist Peter Hadfield (a.k.a. Potholer54) noted:
“What worries your adversary isn’t someone who simply shouts opinions, but someone who asks penetrating questions and won’t fall for evasive answers.”
This paper seems to be stating it’s getting a bit desperate but you wouldn’t know it trying to read the posts here .
It’s a scientific blog and I get that and I know the world appears to be presently warming between 0.2C and 0.3C presently. James Hansen is a sincere scientist so I see no reason for the IPCC to try and get his work. From being published
‘If you wish to claim people understate the climate problem, you have to provide some specific evidence they are doing this. ….
Where exactly do you think they are getting it wrong? ‘
The usual bit–trying to model AND predict the next El Nino. “Getting it wrong” is perhaps not the right wording, as the skill level has yet to produce anything useful. Researchers are still trying though, with many papers featuring machine learning approaches.
Barry E Finchsays
I don’t recall why I’d be “gutted” but I might have lost track. May 2023 I questioned the EEI 1.33 w/m**2 because I’d gotten “Karina von Schuckmann et al’s latest 0.78 w/m**2 (I eye balled 0.88 w/m**2 for last 4 years off her plot with her recent talk), so I looked into it and found of course that was correct that EEI had increased a lot (I recall 0.90 w/m**2 over 20 years) so I updated my notes and started pondering with the new information and I posted:
“OK, I didn’t realize that the EEI has been increasing at a rate as high as the 0.5 w/m**2 / decade. I’ll have to take another look at my quick calculation 5 years ago of 0.20 degrees / decade + 0.06 degrees / decade**2 for +GMST if I ever find the time (it was based of course on what I’d read as the prior increase in EEI since 1970)” so if I was “gutted” it would have been in May 2023 and some people just aren’t keeping up to date because it’s December 2025 now. I wasn’t “gutted” in May 2023, I just updated my notes. It’s interesting.
Piotrsays
“Neurodivergent”: “Barry E Finch, Piotr and Atomsk’s Sanakan must be feeling gutted and embarrassed about their anti-Hansen anti-peer reviewed science trolling all over again.”
What can be asserted without evidence can also be dismissed without evidence,
So stop giving the neurodivergents bad name, the same way you have tarred the reputation of a renewable expert Pedro Prieto by appropriating his name and pushing your claims as him.
The search engines and AI won’t know that you have been an imposter and will forever associate his name with your troll production. Way to pay a “tribute” to him, as you defended your practice.
As for “feeling gutted and embarrassed” – isn’t this what you feel looking in the mirror in the morning? If I were you – incapable of understanding what you read and on what you base your derision toward others, and seeing your opponents constantly running circles around you – I would have felt “gutted and embarrassed” too.
Hansen’s words do not mean what you think they mean, nor do posts of Barry, Atomsk or me.
And no, you can’t hide your intellectual and ethical shallowness by draping yourself in Jim Hansen (the “ authority by association“).
Nor will we pull our punches just because you now appropriated a “ neurodivergent ” label – nobody, save perhaps Susan ;-), will go:
“ Atomsk, for God’s sake – stop battering that neurodivergent boy with falsifiable arguments and with your “Yes or No” questions – see you’d made that poor boy cry ”
Now, go away or we shall taunt you a second time. Fetchez la vache!
Nigeljsays
Piotr: “As for “feeling gutted and embarrassed” – isn’t this what you feel looking in the mirror in the morning? If I were you – incapable of understanding what you read and on what you base your derision toward others, and seeing your opponents constantly running circles around you – I would have felt “gutted and embarrassed” too.”
This guy probably doesn’t feel gutted and embarrassed. He / she obviously has some sort of superiority complex. Some sort of narcissistic psychological issue. He/ she probably genuinely believes they are right. Neuro divergent may in this instance mean genuinely neurodivergent. You and I would be gutted and embarrassed (and would tidy up our act) but dont assume everyone would be. But he / she does indeed misinterpret what people say.
Piotrsays
Nigel “This guy probably doesn’t feel “gutted and embarrassed“.
not at a conscious level
Nigel: “ He / she obviously has some sort of superiority complex.”
that masks the deep seated inferiority: ” A superiority complex is an inflated self-image masking deep-seated inferiority, leading to arrogance, dominance, and devaluing others”
Nigel “Neuro divergent may in this instance mean genuinely neurodivergent. ”
Should an internet troll be considered “neurodivergent”, or just a pathetic type, who hasn’t achieved anything meaningful in life – so he tries to bait opponents, because this would give him the sense of control – thus make his life not pathetic (would a pathetic person be able to “own” supposedly smart people ?). Does it make the multi-troll -neurodivergent ?
Don’t think so. Being a pathetic human being is not something he can’t do anything about, as would be the case for a real neurodivergent.
So the Occam’s razor suggests multitroll adopted this handle to be cute – look, if I call myself “neurodivergent” then it must be ironic – thus proving that I am anything but
b fagansays
Since photons in the infrared wavelengths are being tossed about (or manufactured or re-emitted or down-welling or back-radiated) I’m NOT going to participate in that, but throw in mechanical work being done by the temperature difference between surface and space. The invention will not fix the world but might evolve into producing useful work in specific situations. But one component could be much more useful.
“Scientists Generate Power At Night By Passively Beaming Heat into Outer Space. It’s “Like Solar Cells in Reverse”
UC Davis engineers have invented a Stirling engine that captures Earth’s escaping heat to generate power from the night sky.”
The secret sauce is the coating that the device exposes to the open sky.
“The top plate (warm side) uses a paint that is highly emissive in the infrared. This allows heat to pass directly through a clear section of the atmosphere, called the atmospheric transparency window (between 8 and 13 µm). The heat radiates directly into space, cooling the panel far below the ambient air temperature.
“It doesn’t actually have to touch space physically, it can just interact radiatively with space,” Munday explains.”
But there are now a number of different ways researchers have invented to create coatings (or materials) that radiate their heat in that transparency bandwidth range. Science had a paper maybe ten years ago about a plastic film with embedded glass nanoparticles that radiate in the range. That can be manufactured by the mile on standard plastic sheet machinery. Others have worked on paints and other coatings that do the same.
Another team found a way to treat wood such that the resulting product doesn’t just radiate to space, but it’s stronger, too.
And another one from just last month: “Researchers at the University of Sydney and start-up Dewpoint Innovations have developed a nanoengineered polymer paint-like coating that can passively cool buildings and capture water directly from the air — all without energy input.”
These won’t fix “the world” either, but since IR was a topic, it’s worth thinking about buildings and other structures in hot, sunny, arid places where there’s little water vapor at night to block those IR photons and their trip to space, taking away fairly substantial heat from what’s under the treated surface. Could be a lot of use for that. Zero power cooling.
b fagansays
For whatever reason, the first time I’d read of the plastic film I mentioned above, my first thought of a practical use was shaded shelter for livestock in places where subsistence farming along with goats or cattle happens in hot areas.
More specifically a case would be around the Arabian Sea where they’re first predicting brief episodes where wet-bulb temperatures lethal to large mammals without cooling. If some type of cattle shed with a passively-cooling roof was inexpensive enough, and durable, it could mean the difference between a living farmer without any surviving livestock or a farmer continuing to survive without becoming another refugee. Some kind of earthen walls and maybe a more transmissive mass on the roof so cooling at night would persist a bit in the day – guessing on it, but that could make a difference.
I think something would have to be done to prevent the film or paint from working during the day.
John Pollacksays
The difficulty with passive cooling under extreme wet bulb conditions is that they occur with an extremely high dew point. This means that nearly all of the cooling power would go into condensing water instead of cooling the air. If the condensed water was collected, it could be useful in a desert climate, however.
zebrasays
John, didn’t you just describe a dehumidifier?
John Pollacksays
Zebra, that’s not what I understood b fagan to be describing. He seems to be talking about passive cooling for an animal shelter by coating the top. That’s not my idea of a dehumidifier.
zebrasays
Sorry, John, I was trying to be too clever (but making a serious point).
My understanding of the problem with high wet bulb temps is that the body can’t cool itself through evaporation.
Conventional dehumidifiers produce thermal energy themselves, of course, but this technique would avoid that problem, so even if it didn’t remove thermal energy (or just a little), it should still be beneficial for the occupants. (?)
b fagansays
Hi guys,
I was bringing them up based on the usefulness of these IR-tuned passive radiative materials in general and then, again because the extreme wet-bulb risks are greatest in a lot of areas where low-income pastoralists and/or small farms with cattle or goats are still common.
One thing they’d face that could drive them off their land into big cities is loss of all their livestock, and building sheds with high-powered fans and A/C systems is a non-starter for most of that set of people. So my speculation for a critical use for the material, specific to avoiding large-scale abandonment of lifestyle and locale due to what might be one or two days in summer where there are daytime hours where temperatures are lethal without kind of artificial cooling.
So how to design for low-cost and effectiveness without much or any power. If the passive radiator can do a big piece of the cooling work, survivability of person and their livestock may be enhanced – avoiding a migration trigger for as long as possible while the rest of us end the greenhouse emissions overall.
Another article on the wet-bulb risk , and a visualization tool courtesy of the folks at Columbia Climate School.
Being able to accomplish significant cooling without power, just by choice of building material or coatings is going to be reeeeeeally helpful worldwide.
b fagansays
Hi Steven and John,
I did some poking around and there’s a lot of stuff looking at how to -actually- use the transparency window rather than just my thought of gluing the film onto sheets of corrugated iron. Unsurprising since cooling becomes increasingly important and avoiding extra energy demand and local heat retention are both bonus points. So here are a few links and they seem to also have some interesting other links to more work.
PS on the condensed water, John, that’s part of what they describe in the research written about in the NASA Techbriefs link (last in my initial post). Other research on using passive cooling, including at least one of the ones below, also looks to avoid the problem of condensation – the good news is this is a lot of engineering and construction-trade level work so again, this won’t Fix The World, but it seems likely it will help specific use cases and needs.
This one has passive heating AND cooling. Published: 12 September 2024 in Nature Communications
This one for passive cooling even in high temperatures and significant (up to 100%) humidity. Published 2019 in Optics Express
Nighttime radiative cooling in hot and humid climates
They calculate results but also did some experimental testing of a simple physical mock-up where they got this: “We experimentally demonstrated nighttime radiative cooling in summer with RH from 53–100%. Even at a hot summer night at T-ambient = 29 °C with RH = 100%, we achieved radiative cooling of 5.2 °C below ambient. With a more sophisticated photonic design, a similar, if not better, cooling performance could be achieved in hot and humid climates at daytime.” https://opg.optica.org/oe/fulltext.cfm?uri=oe-27-22-31587
And this one – 2022 in International Journal of Thermofluids
Potential of hybrid radiant cooling with infrared-transparent membranes to improve thermal comfort in hot and humid climate
Four hundred milliwatts per square meter is only about one-hundredth of what a modest solar panel can produce in full sunlight. The upside is that thermoradiative devices can operate at night, without batteries or fuel. The trickle of mechanical or electrical power they provide is still useful in rural areas, deserts, or even deep space habitats.
[…]
Deppe and Munday estimate that the system could potentially scale to six watts per square meter under optimal conditions. Future improvements might involve swapping the working air for helium or hydrogen to reduce friction, using copper for better heat transfer, or adding thermally insulated radiators to boost output during both day and night.
I’m glad they’re upfront about the low power densities; the value seems to be for (in present-day developed-nation context) niche applications.
Apologies for breaking Susan’s Law, but I have to push back on this claim:
The researchers also note that radiative cooling itself could help offset Earth’s energy imbalance: our planet currently absorbs about one watt per square meter more than it emits, driving global warming. By converting some of that trapped heat into mechanical work, their engine effectively prevents a fraction of it from re-entering the atmosphere.
On part 1: depends on the surface which would otherwise be there. Maybe if It’s a low-emmisivity surface like dry rock? (depends on spectrum of albedo) … OLR would be maintained if a perfect emitter at just the right temperature Tc replaces a surface with Th and lower emmisivity ε (in the window*) with
window ∫ ε · B_h· dν = window ∫B_c· dν
i = c,h
E_{Ti} = k·T_i
B_i = (2h·ν³/c²) ÷ ( exp(−hν/E_{Ti}) – 1 )
( https://en.wikipedia.org/wiki/Planck%27s_law )
But actually the ε may need to be lower to make up for the technology’s ε=0 of the outside the window* (*ε=1 of the technology) because the atmosphere’s window has transitional bandwidth.
On part 2: No. It increases the fraction by taking that heat flow out of the atm. window and sending it to do useful work, which is then dissipated ultimately as heat, which now must still find a way out of the Earth System.
[…] But the pure radiative equilibrium (or pure radiative + conductive+diffusive equilibrium**) is unstable to various types of motions; the climate system tends toward a radiative convective-advective*** conductive+diffusive equilibrium**, with a distribution of net radiant cooling (heating = negative cooling) (solar heating correlating with T variation) that generates APE (available potential energy) which is released, converted to KE (kinetic energy) in cumulus convection, Hadley cells, tropicl cyclones, monsoons, baroclinic eddies (extratropical/frontal cyclones), etc. (thermally-direct circulation).
If all motion were held back, the APE would build up more, but the rate of APE production would equilibrate to 0 as pure radiative equilibrium (or pure radiative + conductive+diffusive equilibrium**) would zero-out the non-convective heating and cooling.
), solar power – thermal (max conversion efficiency at Th → T_Sun, but max net energy flux into collector at cold Th ), PV (open circuit V vs short circuit I, … more…), and wind turbines (complete conversion of flow through swept area requires that flow = 0 (complete deflection by pressure); Betz limit),
having a nonzero conversion efficiency requires Tc get cooler, which reduces the OLR; equilibrating to the brightness T of the window maximizes the conversion efficiency, but then there is no flux to convert. (The window OLR / heat flow into Th = Tc/Th ideally. Eg. 6 W/m² supply could come from 300 K Th, 270 K Tc (1-Tc/Th = 90%), 60 W/m² inflow, 54 W/m² emitted.) (Ideally, the window of ε=1 would cover the bandwidth over which the emitted W/(m²·cm¯¹) would be greater than the sfc Fd↓ (Tc still warmer then brightness temperature of ↓flux density @ sfc), with ε=0 outside of that (includes SW bandwidth, so would work in sunlight).
… But probably not a big issue given the likely niche application.
patrick o twentysevensays
Fd = flux density correction:
having a nonzero conversion efficiency requires Tc get cooler, which reduces the OLR; equilibrating to the brightness T of the window’s Fd↓@sfc maximizes the conversion efficiency, but then there is no flux to convert. (The window ( emitted Fd↑ − Fd↓@sfc) / (heat flow into Th) = Tc/Th ideally. Eg. 6 W/m² supply could come from 300 K Th, 270 K Tc (1-Tc/Th = 90%), 60 W/m² inflow, 54 W/m² = emitted Fd↑ − Fd↓@sfc) . (Ideally, the window of ε=1 would cover the bandwidth over which the emitted W/(m²·cm¯¹) would be greater than the sfc Fd↓_ν (Tc still warmer then brightness temperature of ↓flux density @ sfc), with ε=0 outside of that (includes SW bandwidth, so would work in sunlight – wait, that might make up for the OLR dimming ).
OLR would be maintained if a perfect emitter at just the right temperature Tc replaces a surface with Th and lower emmisivity ε (in the window*) with
window ∫ ε · B_h· dν = window ∫B_c· dν
…
Actually, I forgot to include the reflected …
(specular (like a mirror) or diffuse (Lambertian is the most diffuse, right? https://en.wikipedia.org/wiki/Lambertian_reflectance ) … or retroreflective (I’ve observed a bright spot around the shadow of my head in some natural surfaces (gravel, grass), so it’s not only an artificial thing; also glories ( & https://en.wikipedia.org/wiki/Brocken_spectre )… ))
… radiance L from the sfc.
Generally, even in the atmospheric window, only some fraction of the Fd↑ (flux density) from the sfc gets through the atmosphere to become part of the OLR at TOA; but of course maintaining the OLR without other changes requires maintaining either that Fd↑(sfc) with the same angular & spectral distribution of L_ν, or perhaps a different Fd↑ with compensating angular &/or spectral distributions of L_ν, such that the same transmitted Fd↑(sfc) gets to TOA… Anyway, for maintaining the window OLR, window ∫∫∫ t(θ,ϕ)· [ ε(θ,ϕ)·B_h + L_{reflected}(θ,ϕ) – B_c ] · ½·sin(2θ)·dφ·dθ·dν = 0 . where sfc @ T=Tc, ε=1 replaces sfc @ T=Th, ε.
( ½·sin(2θ) = sin(θ)·cos(θ) )
With a sufficient inversion & GHE, sfc LW albedo could increase OLR. OTOH, with sufficient cloud cover, there is no direct effect from the sfc on OLR. If the highest clouds are warmer than the sfc, they … etc.
…“or retroreflective (I’ve observed a bright spot around the shadow of my head in some natural surfaces (gravel, grass),”… it’s subtle.
Davidsays
“It was almost a pre-bunking effort,” — Daniel Swain, climate scientist with University of California Agriculture and Natural Resources
Not paywalled…
“EPA erases references to human-caused climate change from websites
The agency revamped its webpages to feature natural causes of rising temperatures such as the Earth’s orbit.”
By JEAN CHEMNICK | 12/09/2025 06:18 AM EST
E&E News by Politico https://www.eenews.net/articles/epa-erases-references-to-human-caused-climate-change-from-websites/
Off Topic: Lee Zeldin is drawing slowly increasing calls for Pres.Trump to fire him by some conservative groups aligned with MAHA movement over EPA’s sweeping efforts to relax, ignore, postpone, remove rules for regulating a number of toxic chemicals. Maybe a sliver of hope? A Christmas wish perhaps for a man who has overseen such extraordinary damage in so many ways in ten months? (lol, no comments needed, just a momentary spark of fool’s hope by me)
begin quote ->
“I thought we had gone beyond the point of recognizing that when you burn oil, this big, thick black stuff comes up, and it probably isn’t good, especially when you try and breathe it in,” said Dr David Broadstock, with the Lantau Group, and one of the report’s lead authors.
“It’s kind of pretty obvious, and yet we’re still seeing parties wanting to pursue the increasing scale of production of such things,” he told BBC News.
Since taking office President Trump has sought to boost fossil fuel production and roll back US commitments to fight climate change, calling for the country to be a global energy superpower with cheap and reliable resources.
He has also sought to get the US courts to overturn the idea that carbon dioxide is a danger to public health. His government has also followed up with efforts to restrict or limit the efforts of international bodies that set out to tackle warming.
This year has seen efforts at international plastics negotiations, at the international maritime organisation and during COP30 to strike out language that states that climate change is a major issue requiring the world to move away rapidly from fossil fuels.
The disagreement over the Global Environment Outlook report will raise concerns about future negotiations for the Intergovernmental Panel on Climate Change reports as these studies are seen as the bedrock of global efforts to limit global warming. <-end quote
An example of expert herd mentality
is the response to our global warming
acceleration paper. The next day,
these experts unanimously condemned
our paper in the media.
[and on blogs including RC]
Not one of them discussed the physics in
our paper or explained what was wrong.
Instead, there were ad homonym remarks.
“Hansen makes lots of mistakes. Hansen
exaggerates. Hansen is not collegial.”
For many years over a decade now, James Hansen has been asserting in public, repeatedly :
‘What we witness now is scientific reticence on steroids’
Q:What is it that you disagree with your colleagues about?
If I disagreed strongly with my colleagues about it,
then I probably shouldn’t be thinking it,
because of the wisdom of the crowds;
they believe that they’re the ones that are most likely incorrect if everyone else believes something different [sic]
Q: But how is it that you can maintain this level of, maybe belief is not the correct word, conviction, credence in your own ideas, despite being criticized by colleagues? How do you psychologically deal with that?
It’s just that the arguments are wrong. I mean, I don’t see any good arguments against my point of view.
The thing about the cosmology is that it’s a crazy idea. My idea is a crazy idea,
and I admit it’s a crazy idea. But you need something crazy because the conventional ideas
don’t work.
And I think people just sort of go with the crowd.
I’m just not persuaded by going with the crowd. It doesn’t seem to me… I mean,
There are lots of things I don’t know anything about.
And then I say I trust the crowd because I haven’t got any views of my own.
Neurodivergentsays
Reply to JCM
The “fallacy of popular opinions” is the Ad Populum fallacy (Appeal to Popularity/Bandwagon Effect), which incorrectly claims something is true, good, or right just because many people believe it, ignoring evidence or logic. It exploits our desire to fit in (bandwagon effect) and uses emotions or majority agreement as proof, even though history shows the majority can be wrong (like the Earth being the center of the universe). This fallacy is common in advertising, politics, and everyday debates, relying on conformity rather than facts.
How it works:
Argument Structure: “Everyone/Most people believe X, therefore X is true”.
Leverages Emotion: Plays on the human tendency to conform or belong (the “bandwagon effect”).
Avoids Evidence: Substitutes popularity for solid reasoning or factual proof.
In climate science debates, a related error occurs when consensus or model agreement is treated as equivalent to established fact. Many key quantities — such as cloud feedbacks, aerosol forcing, ocean circulation, and regional climate responses — are not directly observed but estimated through models with evolving assumptions. When provisional outputs are presented as settled facts, and model agreement is mistaken for empirical confirmation across the full climate system rather than a limited metric like global mean temperature, this becomes a form of reified consensus rather than evidence-based reasoning.
What’s happening is not just appeal to popularity. It’s a stacked set of epistemic errors that get collapsed into “we have the facts” when, in reality, we have provisional, model-dependent estimates.
The Fallacy of Reified Consensus (also called “Consensus Reification” in philosophy of science)
Definition:
Treating a scientific consensus — especially one derived from models, assumptions, and parameterisations — as if it were a settled body of empirical fact, rather than a provisional framework subject to revision.
In short: Turning agreement into evidence. Calling this out is not anti-science — it’s pro-scientific humility. The disarming in climate dialogues is manifold in sidestepping the “facts”.
We have Argument from Authority (Ad Verecundiam) – “The IPCC says…” – “97% of scientists agree…”
This is used improperly when:
uncertainty ranges are downplayed
dissenting evidence is dismissed without engagement
authority substitutes for falsifiable validation
Accusations of trolling thrown about and allegations that sockpuppets have no facts arguments or scientific support. It does not get more anti-science anti-reason and fallacious than that low step. The bastion of scoundrels and deeply engrained institutional censorship wins the skirmish and lose the war against humanity and truth. The anonymous nobody accusers are the Concern Trolls here.
Model Platonism (Informal but accurate) A category error where:
climate models are treated as the climate itself
internal consistency is mistaken for empirical completeness
This is especially relevant for:
cloud feedbacks
aerosol forcing
ocean heat uptake
regional circulation
Models are tools, not observations. The opposite is deployed by trolls to disarm confuse and manipulate people.
The Fallacy of Precision
Presents narrow confidence intervals, average means, precise numerical targets (1.5°C, 2.0°C),
exact timelines when the underlying system is in fact chaotic, poorly constrained, and dependent on assumptions that change over time
Complexity and Precision does not equate to Accuracy. In Reasoning or Math. Incompetent anonymous Concern Trolls tells you it does. The authoritive experts look on and say nothing.
Surrogate Validation Fallacy is an important one. Definition:
Claiming a model is “validated” because it reproduces one aggregate metric (e.g. global mean temperature), while failing across many coupled components (clouds, ice, precipitation, circulation, regional variability).
Matching one curve only does not mean the work, “the experiment” is understanding the system correctly. When everything else fails real world observations then the one that appears to match is also wrong.
The Trolls and silent expert observers can’t cope with facts evidence nor reason and logic. It just doesn’t compute within their distorted world view anymore. They have become what they rail against.
Barton Paul Levensonsays
N: a related error occurs when consensus or model agreement is treated as equivalent to established fact.
BPL: I’m pretty sure you don’t know what “scientific consensus” means.
Nigeljsays
Neurodivergent @14 Dec 2025 at 9:09 PM
His / her comments are an entire forest of strawman arguments, and non sequiturs and evidence free accusations against nameless people and muddled, confused thinking, and inflammatory claims (ie:trolling). Which is somewhat ironic.
Just more evidence-free ranting and tone trolling that’s likely largely AI-generated. All to bravely run away from evidence and questions that debunk a trolling sockpuppet account.
If crowds were wise we wouldn’t have Trump treating the US as his personal protection racket, and climate denial would not exist. We wouldn’t have ready access to high powered killing machines. We wouldn’t blame victims. We wouldn’t have extreme income inequality. We wouldn’t enable toxic waste to give gazillionaires more att our expense. etc. etc. etc.
GISTEMP gives November with an anomaly of +1.22°C, a little up on October’s +1.19°C.
The NH saw a big rise (+1.47°C to +1.69°C) which is to be expected as northern summers are taking longer to cool off under AGW, while the SH saw a not-quite-so-big drop (+0.91°C to +0.76°C).
2025-to-date (+1.20°C) is running cooler than Jan-Nov 2024 (+1.29°C) but warmer than Jan-Nov 2023 (+1.17°C). This makes a 2nd place 2025 a certainty in GISTEMP, requiring Dec25 to average +91°C or less to drop 2025 down to 3rd warmest. The last time a GISTEMP anomaly that low was seen was Jan 2023.
Meanwhile NOAA gives November with an anomaly of +1.18°C, a little down on October’s +1.19°C, the NH rise (+1.65°C up from +1.52°C) being a bit smaller than the SH drop (+0.71°C down from +0.87°C).
The difference in the Jan-Nov average anomalies for 2025 & 2023 is smaller in the NOAA numbers making a 2nd place for 2025 pretty unlikely, requiring a Dec anomaly above +1.31°C.
Neurodivergentsays
Please note, global and hemispheric temperature anomalies are with respect to the 1901-2000 average.
Do not confuse this data with the Paris set +1.5C anomaly and current tracked GMST
What exactly are you posting about – is it significant posting the exact temperatures from satellites etc
This article states that the past 3 years are the warmest on record and 2023 and 2025 will tie for second warmest.
Are you suggesting the warming is significant ?
Jimsays
Copernicus
The global three-year average temperature for 2023–2025 will likely exceed 1.5°C above pre-industrial levels for the first time.
November 2025 was the third-warmest November on record globally, keeping 2025 on track to be the second- or third-warmest year recorded.
NOAA’s NCEI November 2025 was Earth’s third-warmest November in analyses of global weather data going back to 1850, …………………… NOT 1900-2000 RANGE THAT RODGER USES
.
.
.
According to NOAA, the year-to-date period (January-November) has been the 2nd-warmest on record for the globe, running just 0.01°C (0.02°F) above the January-November value for 2023 and 0.1°C (0.2°F) behind the value for 2024.
.
.
.
James Hansen and Pushker Kharecha 15 April 2025
Abstract. Global temperature for 2025 should decline little, if at all, from the record 2024 level
.
Absence of a large temperature decline after the huge El Nino-spurred temperature increase in
2023-24 will provide further confirmation that IPCC’s best estimates for climate sensitivity and
aerosol climate forcing were both underestimates.
Pete Best: Thanks for the link. I wish people would stop attacking anyone who dares to deviate from their exact interpretation of what is going on. I find your contributions reasonable and reality based. Attempting to lower the temperature and stop arguing over minutiae is admirable. The neverending hostilities are not a useful contribution and make this comment section less useful than it might be.
Once again, as representatives of the supposed ‘extremes’ Hansen, Mann and Schmidt are not very far apart compared to, for example, Russ Vought and Trump’s predatory liars.
Datasays
Dr Gilbz is more than not happy. Her mental health has been in the bin.
Communicating the science is the way
that I can have the most impact. Of
course, scientific research is essential, but we know enough to act already.
Talking about the changes that need to
happen and sharing what we know
already about climate change is
really for me a much better use of my time
and energy.
Dr Gilbz
A Breath of fresh air. The youth are the future. She’s spotted the critical gap. The weakness.
Barry E Finchsays
Pete Best I’m bemused about your question if it’s to MAR. Just looks like plain vanilla relevant asserted quantities to me. Whenever I decide to take a butcher’s at such I challenge any that look incorrect, perhaps ask for citations where not provided, and/or note alternative measurement analyses of the same, perhaps something related, else I don’t comment because I’ve no comment (unless I’m whimsical and thought of a chocolate quip),
Pete bestsays
People here keep on producing charts of warning (it’s not cooling now is it).
Nothing changes but I’m thinking oh the facts will change people’s minds because it hadn’t yet bit one day it will get so warm it’s going to.
The whole edifice of climate change, climate science and the world as it is tells me you will be posting these charts of warming for a long time to come and little to nothing will change because it costs too much, ppl cannot afford it, it’s not good enough or it’ breaks down.
A few Teslas and Chinese EVs won’t change anything
Susan Andersonsays
A delightful ditty about physics, climate, scientists and weather [found via Gavin Schmidt’s Bluesky] Call Me Charney: A GFD Parody https://www.youtube.com/watch?v=qbMwX2uo23U
Dansays
The trumpster dumpter administration’s planned destruction of the National Center for Atmospheric Research (NCAR), which has been a foundation to US atmospheric science scientific research for over 60 years is utterly vile. It is as anti-science, anti-research, anti-data, and anti-facts as it gets. As is anyone who supports the action to deny basic scientific facts that have been extensively and unequivocally peer-reviewed. The action is also destroying America scientific leadership in the world. https://www.usatoday.com/story/news/politics/2025/12/16/trump-dismantle-national-center-atmospheric-research-climate/87798771007/
Dean Myersonsays
I have read that many foreign research institutes and their host countries have initiated programs to recruit American scientists abroad. It is reverse brain drain as scientists leave in order to avoid ideological control of science. Not all American scientists have the option of moving abroad, but those US research facilities not under direct US government control are also being attacked.
Susan Andersonsays
Still taking that in (NCAR threats, and the intemperate lies about reality). It’s hard to believe. I keep thinking they can’t shock me any more, but I was wrong.
My only hope is that public outrage will be so high they’ll put it off.
Dean Myersonsays
News flash – a large bipartisan deal to fund most of the government, a so-called minibus bill, has been stopped dead in its tracks by two Senators from Colorado who said Congress must prevent Trump from dismantling NCAR if they want the deal to go through.
Davidsays
Dan’s use of the word “vile” is a spot-on description of this latest plan to conduct yet another malicious act of destruction of federal science efforts by the Trump Administration.
Hopefully, people will get out their phone and call their U.S. Representative and both of their state’s U.S. Senators to make one’s thoughts known. Particularly those of us with Republican representation.
ozajhsays
And all because the State government won’t play ball with pardoning Tina Peters.
Datasays
Everything that follows is based on measured atmospheric data, not model projections or policy scenarios.
What this means, in simple physical terms
Earth is currently out of energy balance. More energy is coming in than going out.
Right now, that imbalance is about +1 watt per square metre (W/m²). That may sound small, but spread across the entire surface of the planet, it represents an enormous and continuous heat input. Because the oceans absorb heat slowly, much of the warming this imbalance causes has not happened yet. But, it is already locked in.
Even if greenhouse gas levels stopped rising tomorrow, significant additional warming is unavoidable because the system has not yet equilibrated.
Climate forcing is the driver — not targets or pledges
Climate forcing is the push that causes warming. Greenhouse gases reduce how much heat escapes to space.
Doubling CO₂ causes about +4 W/m² of forcing. Today, total human-caused forcing is already around +2.5 to +3 W/m², even after subtracting the cooling effect of aerosols. The key point is warming follows forcing, not political timelines.
The forcing is not slowing — it is accelerating
Over the past 15 years, the growth rate of greenhouse gas forcing has risen sharply, reaching about ~0.5 W/m² per decade. This is not a projection. It is measured from atmospheric data.
That rate is far higher than what would be required to stabilise temperature, let alone reduce warming.
Reality is tracking RCP8.5 — not RCP2.6
The IPCC’s “safe” pathway (RCP2.6) assumed a rapid slowdown in greenhouse gas forcing growth.
That slowdown never happened. Measured forcing growth has diverged dramatically from RCP2.6 and instead tracks close to RCP8.5, the high-end emissions scenario once described as the “worst case” scenario.
This means staying below 2 °C is now implausible. Staying below 1.5 °C is already gone. Impossible. While “Net Zero by 2050” does not align with physical reality under any plausible interpretation of current forcing trends.
Carbon capture cannot close the gap
In theory, carbon capture could compensate for the difference between reality and RCP2.6. In practice, using current technology, the cost of capturing that gap would already be $2.4–5 trillion per year (as of early 2023)
And the gap — and the cost — keeps growing. This alone makes the Net Zero framing non-credible at planetary scale.
The key chart is missing for a reason
For 25 years, Hansen and colleagues have published a simple, transparent chart showing actual greenhouse gas forcing growth — the so-called “colorful chart”. (See link)
Despite relying on the same underlying data as the IPCC, this chart does not appear in IPCC reports.
The omission matters because the chart shows, unmistakably, that:
Forcing growth accelerated
The climate problem worsened
Policy narratives did not match physical trends
The central scientific failure
Climate models and scenarios are useful — but data must come first. When measured forcing trends are ignored or downplayed, projections become detached from reality.
The result is false reassurance, built on modelled scenarios that assume future actions and technologies that do not exist at the required scale or with demonstrated feasibility.
The situation now is fundamentally different
This is no longer an early-warning phase. We are already in the consequence phase. Warming is accelerating. Feedbacks are activating. Irreversible thresholds are closer.
The Decisions made in the next 5–10 years will shape outcomes for centuries — not because of targets, but because of physics.
Ending where the responsibility lies
If policymakers misunderstand the severity of the situation, scientists share responsibility when they allow unrealistic scenarios to be treated as credible futures.
The data are clear. The forcing is rising fast. The trajectory is wrong.
…………………
Inspiration and data source
Abstract
The growth rate of greenhouse gas climate forcing has increased rapidly over the past 15 years, reaching about 0.5 W/m² per decade. This measured acceleration shows that reality has diverged sharply from the IPCC’s low-emissions scenario (RCP2.6) and instead tracks close to the high-emissions RCP8.5 pathway. As a result, limiting global warming to below 2 °C is now implausible. The continued rise in forcing demonstrates that mid-century “net zero” targets are not aligned with physical reality. Transparent, data-driven analysis of climate forcing must take precedence over scenario-based projections if dangerous interference with the climate system is to be properly understood.
Authors James Hansen Pushker Kharecha Dylan Morgan
Data. it’s nice to have that laid out. Essentially everybody who comments here knows and understands those physical science things and more for months, years, decades variously (has a worthwhile physics education). I had no idea that there has been some 25-year conspiracy or whatever within the U.N. IPCC framework to exclude the work of James Hansen. Are you able without risking Actionable comment to pin it down to groups of persons or to the Governments of countries with specifics (not just “Petro States blah blah). Real checkable specifics? Seems interesting.
Plenty of useful data, detail and analysis in this study: Carbon Brief. Analysis: What are the causes of recent record-high global temperatures? Zeke Hausfather 10.12.2025 | 3:00pm
In this article, Carbon Brief explores four different factors that have been proposed for the exceptional warmth seen in recent years. These are:
A strong El Niño event that developed in the latter part of 2023.
Rapid declines in sulphur dioxide emissions – particularly from international shipping and China.
An unusual volcanic eruption in Tonga in 2022.
A stronger-than-expected solar cycle.
Carbon Brief’s analysis finds that a combination of these factors explains most of the unusual warmth observed in 2024 and half of the difference between observed and expected warming in 2023.
However, natural fluctuations in the Earth’s climate may have also played a role in the exceptional temperatures, alongside signs of declining cloud cover that may have implications for the sensitivity of the climate to human-caused emissions……
Nigelj, your description of the likely causes of recent record-high global temperatures is missing the recent paper of Matthew H. England et al (MEetal). Why? As soon as I saw the rapid rise of GMST late Spring 2023 I thought “That’s the ocean because the ocean modulates surface-air temperatures because the ocean has ~all the heat content that is significant on these times scales (land is tens of thousands of years and longer responding). So only ocean shoaling can do this much (or a big part of it). MEetal found that in 2023 the El Nino had an effect (presumably unusual and powerful) in shifting a High-Pressure system which slowed northern ocean surface winds and MEetal noted that rising sea surface temperatures (SSTs) followed this around the northern oceans. Why not being considered as a significant contributor?
Barry E Finchsays
My “northern ocean(s)” S.B. “North Atlantic Ocean”. I forgot that since July.
Nigeljsays
Barry E Finch, Ocean shoaling sounds plausible to me. The problem is with thousands of papers being published almost weekly its possible Carbon Brief are not aware of the paper you mentioned. Might be worth your time emailing them.
Just on another tangent. When I looked at the carbon brief graph of global surface temperature I notice the so called pause after 1998 the temperatures eventually drop slightly below the long term linear trend line then after 2015 temperatures creep above this line a little. Just eyeballing the graph, hope the eyes are working properly. Makes me wonder if whatever caused the so called pause which appears to be some sort of ocean and wind driven process might have now reversed. However the recent warming spike clearly has a combination of causes several of them anthropogenic with potential to accelerate the warming trend.
Nigelj,
I wasn’t particularly ‘blown away’ by Zeke Hausfather’s CarbonBrief piece. To me, it read as the same exercise as performed through the months-gone-by and coming to very similar conclusions – that the “bananas!!” resulted from a conspiring set of miscreant climatic stuff. That may be so. But it doesn’t feel a robust conclusion to me.
I think we can say that the dropping global temp anomalies do point to there being no forcing from aerosols as a major cause of the “bananas!!” That still leaves the possibility of a cloud feedback amplifying a natural wobble. Or it may be the “bananas!!” are what El Niño’s have come to look like now, with or without a potential big feedback.
My graphical comparisons of the “bananas!!” with previous El Niño haven’t been updated for quite a while & for clarity I’ve posted new graphics showing global, NH & SH GISTEMP through the 1997/98, 2015/16 & 2023/24 El Niño’s HERE – Posted 18th December 2025.
The global anomalies 2022-25 (top graph) don’t show such a seriously massive difference from 2014-17 or 1996-99 wobbles. The warm wobble in 2023 wasn’t actually that big but it did arrived very early, didn’t cool that much through 2024 with another big warm wobble following in late-2024 and signs of yet another warm wobble (size yet unknown) in late-2025.
These warm wobbles are in the main actually the NH autumns not cooling down as quickly as in the past and this means NH autumns usually have anomalies rising faster than the rest of the year, and this now big enough to feature large in the global values. They can be less of a feature in La Niña years. And plotting out these NH anomalies (middle graph) shows these warm wobbles in all their splendour.
The SH (bottom graph) shows that the initial bit of those rising global anomalies was in the SH autumn with the SH (so far) has not seen a lot of cooling reversing that wobble. Note that the cooling 2014-18 wasn’t particularly rapid either. But the SH warmth does seem to e hanging on, although I’d speculate on another mechanism at work. It may be a one-off event but maybe not – I do wonder if there is a speculative SH wobble through the SH winter beginning to appear, but saying this, such thoughts are somewhat fanciful so far.
Datasays
Recent analyses, including those summarised by Carbon Brief, offer plausible short-term contributors to the exceptional warmth observed since 2023. These discussions are useful. However, they are often received and deployed as more definitive than the underlying uncertainties allow.
In particular, large uncertainties remain in aerosol forcing, aerosol–cloud interactions, and cloud feedbacks. Given the size of these uncertainties, conclusions about the relative contribution and sufficiency of individual short-term factors should be treated as provisional rather than settled.
This matters because some analyses implicitly treat model-based expectations as stable reference points, while unresolved uncertainties — and peer-reviewed challenges to those expectations — receive limited direct engagement. Hansen et al. (2025), whether ultimately right or wrong, present a peer-reviewed analysis that makes falsifiable claims and argues that recent observations may point to a structural underestimation of climate sensitivity in current models.
Their argument does not deny aerosol or cloud uncertainty; it incorporates it. The claim is that uncertainty does not simply add noise, but may implicate core model assumptions — particularly the combination of aerosol masking, ECS tuning, observed forcing, Earth’s energy imbalance, ocean heat uptake, and paleoclimate constraints.
By contrast, analyses that focus primarily on additive short-term factors operate largely within existing model expectations. If uncertainties are large, confidence should scale accordingly.
Short-term forcings can explain anomalies only if the underlying model framework is sound — Hansen’s work questions that assumption, and that challenge still needs direct engagement.
Barry E Finchsays
On “uncertainty” and “paleoclimate constraints” mentioned and me trying to push work onto others does anybody know what I wondered the last couple years, where did Jim Hansen’s 3.0 W/m**2 for GHG forcings of warming from the LGM at AGU 2011 come from and what better science since 2011 improved it to Jim’s newer 2.25 W/m**2 for GHG forcings that therefore has increased Climate Sensitivity by 13% (not insignificant) additional t the 40% increase due to LGM GMST increase was ~7.0 not ~5.0 degrees?
Datasays
Reply to Barry E Finch
does anybody know what I wondered the last couple years?
I do not. I know of no one who does. Observations of your commentary suggests you do not know either, but perhaps you’re still trying. So, good luck.
Piotrsays
“Data” says 22 Dec 2025:
“ Reply to Barry E Finch – “does anybody know what I wondered the last couple years?”
I do not. I know of no one who does.
Well, if you DIDN’T CUT your “quote” JUST as Barry explained what he was wondering about, perhaps it wouldn’t be such an impenetrable mystery to your brilliant mind. Here you go:
Barry: “does anybody know what I wondered the last couple years where did Jim Hansen’s 3.0 W/m**2 for GHG forcings of warming from the LGM at AGU 2011 come from
Data: I do not. I know of no one who does. Observations of your commentary suggests you do not know either
So your oh so witty, repartee only shows how much your observations/ethical integrity.are worth.
Now, quickly change your handle, so the new one can deny the responsibility for … “Data”‘s manipulation.
Datasays
The great scientist Richard Feynman famously ridiculed scientific reticence.
with reference to the late Wally Broecker, in Sophie’s Choice Jim Hansen writes “…the quality of Wally that I admire most was his courage to speculate.
Progress in science depends on people who have the knowledge and the courage to attempt an
interpretation of available data, which are always incomplete and contain measurement flaws.
This quality is the antithesis of scientific reticence. Sometimes Wally’s proposed interpretations
were criticized as a “house of cards,” and, indeed, they often came tumbling down, but, even in
such cases, he stimulated research. Other scientists criticized his proposal, flaws were exposed,
and improvements were made – that is how scientific progress is made rapidly.”
A Global warming projection. Assumption of at least a moderate El Nino beginning in 2026
leads us to the projection in Fig. 5, with global temperature reaching a minimum at or above
+1.4°C within several months and then rising to a record global temperature of about +1.7°C in
2027. This new record will occur only four years after the 2023 El Nino, so additional,
underlying, global warming at the accelerated rate of 0.31°C per decade is only about 0.1°C.
Fig. 5. Projected global temperature in 2026 and 2027 https://substackcdn.com/image/fetch/$s_!y_Vt!,w_1456,c_limit,f_webp,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2F480bbefc-da3a-4870-8609-dc60d57e5438_777x418.png
Numerous models and evidence point toward an El Nino beginning in the second half of 2026.
For example, Fig. 4 is an ensemble of projections of the current NOAA NCEP model.
We can use the well-founded expectation of this upcoming El Nino for a further test of
global warming acceleration.
Warm or cold anomalies need to exceed 0.5°C for several consecutive months to qualify as
El Nino or La Nina. Beware that rapid global warming of the past half century is perturbing
the quantitative significance of Nino3.4. The strongest El Nino relative to its surroundings
was the 1997-98 El Nino;
the 2015-16 and 2023 El Nino strengths are exaggerated by the effect of global warming
on the Nino3.4 index, which also diminishes apparent strength of recent La Ninas.
Two years ago (29 March 2024) Hansen et al projected that global warming in the
then-ongoing El Nino would rise much more than in prior El Ninos, raising global
temperature to at least +1.6°C, and that temperature after the El Nino would fall only
to +1.4°C (see Fig. 2).
(Expectation of unusual warming was based on realization that a long-term global
cooling effect of aerosols had recently shifted to warming, as we will discuss further
in an upcoming post.)
Consistent with this prior projection, Hansen et al expect a minimum 12-month running-
mean temperature of about +1.4°C to be reached in the first half of 2026, after which
global temperature should begin a rise that will continue into 2027, reaching a new record
high, as discussed above.
Global temperature of +1.47°C in 2025 relative to 1880-1920 is the 2nd highest in the period
of instrumental data, about 0.1°C cooler than the 2024 record high (Fig. 1) in the GISS analysis.
(Hansen et al assume the exact December temperature has imperceptible effect on the
2025 temperature in Fig. 1).
The 3-year (2023-2025) temperature is +1.5°C relative to 1880-1920. Hansen et al will provide
details on the geographical and temporal temperature change in a communication in early
2026.
Abstract. Global temperature in 2025 declined 0.1°C from its El Nino-spurred maximum
in 2024, making 2025 the second warmest year. The 2023-2025 mean is +1.5°C relative to
1880-1920.
The 12-month running-mean temperature should decline for the next few months,
reaching a minimum about +1.4°C. Later in 2026, we expect the 12-month running-mean
temperature to begin to rise, as dynamical models show development of an El Nino.
We project a global temperature record of +1.7°C in 2027, which will provide further
confirmation of the recent global warming acceleration.
Kevin Anderson once again demonstrates that it is very easy for the political and economic perspective on climate change and how to tackle it to delude itself and tell the public all is well and going in the right direction.
The reality iof the issue is that until we address human behaviour and its implications we arnt going fir enough
Jimsays
Reply to Pete Best
Kevin’s data explanations and political insights are first class. Unfortunately COP isn’t failing because of bad leadership or bad science. COP is failing because consensus-based sovereign bargaining is structurally incapable of governing a physical system.
COP outcomes are therefore merely performative in nature. We cannot expect different results from repeating the same approach that has dominated these negotiations for thirty years. Focusing on COP30 Brazil failures highlights the impossible 100% Consensus requirement among 192 nations with individual critical needs. The original UNFCCC Rules ensure failure.
That failure is structural not political. And not a failure of science but in it’s application through compromised agreements among players, big and small, all kicking the can down the road. The COP structure needs root and branch reform. As does the IPCC structure–not the science they are to make wise judgements about.
Kevin is indeed right. But there is no venue or process where it can made to work. Only the chattering classes where nothing gets done.
Jimsays
Heard some climate news on BBC radio last night and did some searching for more details. Apologies if you already know. Things look grim in the US across the board.
At the AGU 2025 Fall Meeting (December 15–19), climate researchers adopted notably cautious and strategic messaging in response to journalists. This reflected a hostile political climate in which the Trump administration proposed closing major facilities such as NCAR and dismissed climate research as “alarmism.”
In several high-profile sessions, federal scientists avoided potentially politicized terms like “fossil fuels” and even “climate change.” During the 2025 Arctic Report Card briefing, for example, NOAA’s acting chief scientist addressed Arctic warming in terms of “long-term environmental observations,” without explicitly naming human drivers.
Instead, researchers emphasized data continuity and measurement reliability, underscoring that observational records remain accessible and scientifically robust rather than drawing policy-linked conclusions.
AGU also encouraged disciplined media engagement, advising scientists to rely on precise, concrete metrics (such as specific glacier retreat rates) and to minimize jargon.
As discussion of once-taboo topics like solar geoengineering increased, scientists framed these issues through shared ethical frameworks focused on responsible research and governance, avoiding personal advocacy.
Despite public caution, many researchers simultaneously engaged in internal advocacy, including coordinated efforts to lobby Congress to protect climate research infrastructure such as NCAR.
During the 2025 Arctic Report Card press conference at the AGU Annual Meeting, NOAA’s Acting Chief Scientist Steve Thur was questioned by journalist Barbara Moran regarding the agency’s stance on the causes of climate change
……………………….
On Tuesday, Russel Vought, President Donald Trump’s Office of Management and Budget Director, said the administration plans to close the National Center for Atmospheric Research, a Colorado research facility that has operated since 1960. The facility “is one of the largest sources of climate alarmism in the country,” Vought said in a post on the social media site X.
And this year, unlike the other years since 2006 when NOAA published the first Arctic Report Card, the agency declined to issue a news release about it.
Thur, asked if NOAA will continue to publish report cards in the future, said the agency will continue the work that goes into the annual documents.
“What I would say in response to that question, is that we’re here today and that we have released the 2025 version,” he said. NOAA has continued its long-term environmental observations in the Arctic, both with satellite observations, he said. “So I think one of the things that the community can rely upon is that our efforts to continue to observe the planet will remain present,” he said.
Thur also demurred when asked whether NOAA still stands by the statements about fossil fuels made by the agency’s prior administrator, Rick Spinrad. When last year’s report was issued at the end of the Biden administration, Spinrad said the changes in the Arctic were directly related to fossil-fuel emissions. Thur did not mention fossil fuels.
“What I would say in response to that question is that we recognize that the planet is changing dramatically,” he said during the news conference. “Our role within NOAA is to try to predict what’s going to occur in the future by documenting what’s occurring today,” he said. “There is a human role, as our administrator currently, Dr. Neil Jacobs, said during his congressional confirmation hearing, for humans in influencing those changes.”
Matthew Druckenmiller of the National Snow and Ice Data Center, another lead editor of the report, made no such equivocations.
“Let us start by first acknowledging that the warming of our planet driven by human greenhouse gas emissions into our atmosphere is amplified in the Arctic,” he said near the start of the news conference. “The Arctic continues to warm much faster than the globe overall, amplified by the loss of reflective sea ice and snow, causing more of the sun’s heat to penetrate into land and ocean.”
Druckenmiller also said the Trump administration did not interfere with drafting of the report.
But some saw NCAR’s dismantling as a reason to leave the US. Space physicist Alexandros Chasapis is planning to move back to France to continue his research.
“The fact that this is on the table on its own is causing damage,” he said of closing NCAR. “Even if they walk this back tomorrow, you lose trust.”
What was clear to countless researchers at AGU is the scientific value of NCAR. “Every scientist has benefited in some way from what NCAR does,” said Marc Alessi, a science fellow at the nonprofit Union of Concerned Scientists.
Several scholars and cultural critics have voiced perspectives that align with the view that the current political climate—characterized by juvenile rhetoric and “pissy” plaque rewritings—is a reflection of a deeper, systemic cultural decay in the United States.
Historians and political scientists have increasingly identified parallels between 2025 America and the rise of European fascism: Ruth Ben-Ghiat (NYU) An expert on strongmen, she notes “striking” similarities between current political tactics and Mussolini’s 1920s laws that dismantled judicial independence and centralized power. She argues that Trump’s use of “ritual humiliation” and victimhood narratives conditions followers to see political opposition as “the enemy within”.
Daniel Ziblatt (Harvard): Author of How Democracies Die, he observes that the combination of false allegations and threats of retribution against opponents mirrors the tactics of 1930s European fascists.
Critics point to a broader “mindset maturity” issue and a culture of narcissism permeating the American public. Academic studies highlight “national collective narcissism,” where a belief in national exceptionalism—threatened by perceived outsiders—justifies authoritarian leadership and the disregard for democratic procedures.
Observers see the “violence” of the current moment manifesting both rhetorically and physically. As of October 2025, approximately one-third of Americans believe political violence may be necessary to “set the country on the right path”—a significant increase from previous years.
Following on from the above news reports, this comment brings together several recent sources, historical perspectives, and ideas I’ve been reading and thinking about over the past year, alongside my own reflections. I asked an AI tool to help review the draft for clarity and coherence. These are challenging times for science and institutions globally — though the U.S. currently appears to be a focal point.
Where to from here: Climate Science in an Age of Imperial Decline and Institutional Simplification
What we are witnessing in the U.S. is not simply a communications failure or a temporary political aberration, but a deeper structural breakdown. Joseph Tainter’s framework helps clarify this: societies under rising complexity eventually reach a point where returns on complexity turn negative. At that stage, dysfunction is no longer anomalous — it becomes emergent. What looks like juvenile political theater, historical rewriting, or performative outrage is better understood as a system that can no longer manage reality nor complexity, and is beginning to fragment.
This interpretation aligns with a broader “declinist” perspective. Alfred McCoy has long argued that the U.S. is following the familiar arc of late-stage empires, marked by imperial overstretch, a bloated security apparatus, and costly interventions that undermine domestic resilience. By his account, the early 2020s represented a critical inflection point. Similarly, historian Mike Duncan has suggested that the U.S. has passed its imperial zenith, with current political devolution echoing the late Roman Republic — where inequality, institutional capture by private interests, and erosion of civic norms led citizens to seek refuge in demagogues rather than governance.
Climate science is not peripheral to this decline; it sits directly in its path.
As institutions deteriorate, the capacity to observe, measure, and respond to physical reality becomes a political liability. In late 2025 this reached a critical point. The Department of Government Efficiency (DOGE), even after formally closing, effectively institutionalized a logic of “simplification” that translated into mass attrition across the federal workforce. By December, more than 200,000 civil servants had departed, including thousands from NASA and HHS. The loss was not merely numerical — it represented decades of accumulated institutional memory, tacit knowledge, and continuity of observation.
From a Tainter perspective, this is not reform but forced simplification: a deliberate reduction in the state’s ability to perceive and manage complex physical systems. Climate research becomes especially vulnerable under such conditions because it depends on long time-series, stable institutions, and trust in measurement rather than ideology.
Complicating matters further is a growing convergence across the political spectrum toward what some critics describe as “liberal authoritarianism.” The neoconservative logic that once justified torture, surveillance, and disinformation — treating dissent as intent to harm — has increasingly been adopted in softer form by parts of the liberal establishment. Nuance is replaced by moral sorting, and disagreement becomes evidence of bad faith. This dynamic further fractures the social fabric and leaves climate science trapped between denial on one side and performative consensus enforcement on the other.
In such an environment, inconvenient truths are not debated; they are sidelined. The erosion of climate science is therefore not just about censorship or funding cuts, but about a broader collapse in the legitimacy of reality-based reasoning itself.
So how does climate science survive — even after Trump?
Not by persuasion alone, and not by returning to business as usual. In the short to medium term, survival depends on routing around federal dysfunction: state-level support, university-based refuges for expertise, independent data archiving, and communication that emphasizes concrete, locally experienced consequences of lost observational capacity. Farmers understand degraded weather forecasts; coastal communities understand missing tide gauges.
Longer term, recovery requires rebuilding institutional resilience rather than assuming political normalization will fix the problem. Legal protections for scientific integrity, durable stewardship of observational data, and public communication that explains what is lost when institutions fail matter more than rebutting bad-faith rhetoric online.
The core issue is not misinformation alone, but institutional collapse. Climate science persists not because society is ready to hear it, but because physical reality continues to assert itself. The task now is to preserve the capacity to observe that reality until institutions — and civic culture — are capable of facing it again.
According to the UNEP Emissions Gap Report 2025, global emissions reached a record 57.7 GtCO₂e in 2024, an increase of 2.3% over the previous year, more than four times the average annual growth rate of the 2010s. On the current trajectory, the world is heading toward 2.5°C of warming, even assuming full compliance with Nationally Determined Contributions, which is far from guaranteed.
UNEP’s Global Cooling Watch 2025 further estimates that avoiding catastrophic outcomes would require removing roughly 10 billion tonnes of CO₂ annually, effectively creating the planet’s second-largest industry, after fossil fuels, financed by more than one trillion dollars per year. These reports quantify need but leave open essential questions: who will act, under what legal framework, and with what financing?
Recognizing that emissions must fall 42% by 2030 compared with 2019 is not a plan.
COP30: resistance without regression
For many, the mood at COP30 contrasted sharply with the sense of possibility that followed Brazilian President Lula da Silva’s electrifying 2022 speech at COP27, when Brazil’s candidacy to host COP30 was celebrated as a potential turning point. That moment suggested a decade after Paris could deliver a science-aligned breakthrough from the heart of the Amazon.
But political winds shifted. Climate denialism gained ground. The U.S. left the Paris Agreement and this year, for the first time, they were not present at a COP. A parallel “politicized science” emerged, distorting debate. In this context, Dubai’s COP28 (held in a petrostate) is now remembered for at least mentioning a “transition away from fossil fuels.” Belém’s COP30 could not even agree on that, and in terms of deforestation, the final text was nearly identical to that of COP29 in Baku. A feared collapse was avoided, but only by holding the line, not advancing it.
Breaking the vicious cycle
If politics is the art of the possible, it becomes art only when creativity expands what is possible. As Nelson Mandela reminded us: “Everything is impossible until it’s done.” After thirty years of incrementalism, with Paris targets at risk of collapse this decade, continuing the same strategies is no longer responsible.
Or rational?
Chucksays
I don’t see how humanity survives this. 3 C by 2050. 5 C by the end of the century! Someone help me out with this. Thoughts?
Those are incorrect claims from the German Physical Society (DPG) and the German Meteorological Society (DMG). They’re cherry-picking a small number of CMIP6 models that are known to overestimate warming, including warming up to 2025. If those models are too warm in 2025, then there’s good reason to think they’ll also be too warm for 2050. The observed warming trend, better observationally-constrained CMIP6 models, CMIP5 models, the IPCC, etc. instead show we’re on pace for ~2°C by 2045-2050, 3°C by 2075-2090 (2060 at the absolute earliest), and ~3.5°C by the end of the century.
Datasays
Atomsk’s Sanakan says
23 Dec 2025 at 7:23 AM
Those are incorrect claims from the German Physical Society (DPG) and the German Meteorological Society (DMG). They’re cherry-picking a small number of CMIP6 models that are known to overestimate warming,
Data: You need to prove that allegation is true, science based, then show your work and that list of “cherry-picked CMIP6 models”
AS: including warming up to 2025.
Data: no one needs a model to see what the warming up to 2025 are. But if they were serious then the diferences between the models and the observation would be already clear.
AS :If those models are too warm in 2025, then there’s good reason to think they’ll also be too warm for 2050.
Data: Prove that is true, show your work and reference everything.
AS : The observed warming trend, better observationally-constrained CMIP6 models, CMIP5 models, the IPCC, etc. instead show we’re on pace for ~2°C by 2045-2050, 3°C by 2075-2090 (2060 at the absolute earliest), and ~3.5°C by the end of the century.
Data: Prove that is true, show your work and reference everything.
Emotionally charged incoherent troll dumps on a forum do not count as credible science. Forster etc aren’t scientifically valid nor support your claims. ~2°C by 2045-2050 is blatantly false and unfounded.
Peer-Review doesn’t confirm a paper’s analysis and findings are in fact correct Scattered paintballs of ‘claims’ on a wall isn’t coherent science, let alone valid evidence of anything. Please take your unsubstantiated rants and trolling somewhere else.
None your tripe addresses cogently addresses evidence I linked, sockpuppet account. Let folks know when you can actually manage that. I doubt you’ll ever be able to, since you couldn’t even manage answering basic questions you were asked.
Re: “~2°C by 2045-2050 is blatantly false and unfounded.“
Great illustration of how Data disinforms, along with their sockpuppet accounts Jim, Neurodivergent, etc. The link in the post they replied to already cited evidence on this, despite Data pretending otherwise and willfully ignoring the evidence cited. That debunks their pretense of caring about references and evidence.
Thedocument in question used Paris Agreement targets. Warming for those targets is calculated using a 20-year mean to mitigate bias from outlier years. This puts us at ~1.4°C. Extrapolating recent observed warming of ~0.26°C/decade implies 2°C by 2045-2050, not near 3°C:
– Forster 2025: “The rate of human-induced warming for the 2015–2024 decade is concluded to be 0.27 °C per decade with a range of [0.2–0.4] °C per decade). This agrees with the decadal trend in observed warming of 0.26 °C per decade (also calculated as a linear trend through 10-year periods – see Sect. 7.1).”
– IPCC Special Report, “Global Warming of 1.5°C”, Summary for Teachers: “It is stated that the global temperature has already increased by approximately 1.0°C. It says further that global warming is likely to reach 1.5°C between 2030 and 2052 if it continues to increase at the current rate. Find out the current warming rate.
[…] Solution : the current rate of warming is approximately 0.026°C per year.”
Using a slightly higher trend of ~0.28°C/decade for reasons gone over in that post, implies 1.5°C by around 2029/2030, 2°C by 2045-2050, 3°C by 2075-2090, and 4°C by 2105-2130. That’s in the range of other projections, observationally-constrained CMIP6 models, CMIP5 models, the IPCC, etc. It’s also less warming than 3°C by 2050 and 5°C by 2100:
– Xu 2018: “the next 25 years are poised to warm at a rate of 0.25–0.32 °C per decade”
– Hansen 2023: “Edges of the predicted post-2010 accelerated warming rate (see text) are 0.36 and 0.27°C per decade.”
None of this evidence would ever get through to a sockpuppet account like Data.
Datasays
Reply to Atomsk’s Sanakan Jan 1
Observed warming trends and CMIP projections are scenario-dependent and highly uncertain beyond a few decades; top-of-atmosphere energy imbalance, feedbacks, and emission pathways make exact dates for 2–3°C or 4°C warming inherently approximate.
CMIP outputs are plausible pathways under defined assumptions, not precise predictions.
My Ref:
The primary purpose of these projections is to inform policymakers about the potential consequences of different emission pathways, highlighting the urgency of reducing greenhouse gas emissions. Therefore, any suggestion that CMIP outputs, the IPCC, or other frameworks are making a temperature prediction for 2050, 2100, or any specific future period is scientifically invalid; these models do not make such predictions.
Here are the relevant references showing Reply to Atomsk’s Sanakan “claims” based upon his multiple false / as yet unproven/falsified CMIP assumptions.
Atomsk’s Sanakan says
23 Dec 2025 at 7:23 AM
Those are incorrect claims from the German Physical Society (DPG) and the German Meteorological Society (DMG). They’re cherry-picking a small number of CMIP6 models that are known to overestimate warming, including warming up to 2025. If those models are too warm in 2025, then there’s good reason to think they’ll also be too warm for 2050. The observed warming trend, better observationally-constrained CMIP6 models, CMIP5 models, the IPCC, etc. instead show we’re on pace for ~2°C by 2045-2050, 3°C by 2075-2090 (2060 at the absolute earliest), and ~3.5°C by the end of the century.
Atomsk’s Sanakan “whole argument” is relying on his assertions about CMIP modelling output and their assumptions.
SEE my Reply > Data says
23 Dec 2025 at 11:41 PM
Atomsk’s Sanakan says
23 Dec 2025 at 7:23 AM
Those are incorrect claims from the German Physical Society (DPG) and the German Meteorological Society (DMG). They’re cherry-picking a small number of CMIP6 models that are known to overestimate warming,
Data: You need to prove that allegation is true, science based, then show your work and that list of “cherry-picked CMIP6 models”
AS: including warming up to 2025.
Data: no one needs a model to see what the warming up to 2025 are. But if they were serious then the diferences between the models and the observation would be already clear.
AS :If those models are too warm in 2025, then there’s good reason to think they’ll also be too warm for 2050.
Data: Prove that is true, show your work and reference everything.
AS : The observed warming trend, better observationally-constrained CMIP6 models, CMIP5 models, the IPCC, etc. instead show we’re on pace for ~2°C by 2045-2050, 3°C by 2075-2090 (2060 at the absolute earliest), and ~3.5°C by the end of the century.
Data: Prove that is true, show your work and reference everything.
Emotionally charged incoherent troll dumps on a forum do not count as credible science. Forster etc aren’t scientifically valid nor support your claims. ~2°C by 2045-2050 is blatantly false and unfounded.
Your post contains no cited evidence nor does it address the evidence I cited, sockpuppet. So I’ll continue to go with peer-reviewed published evidence from climate researchers like Forster et al., while you contradict your other sockpuppet account in your desperate attempts to dodge evidence. You don’t know better than published experts and you never will. Stew about it.
– Data says: “Peer-Review doesn’t confirm a paper’s analysis and findings are in fact correct Scattered paintballs of ‘claims’ on a wall isn’t coherent science, let alone valid evidence of anything.”
– Data’s sockpuppet account Jim says: “Atomsk’s Sanakan the Anonymous Flamewar Warrior and Internet Troll is claiming to know more than Gavin Schmidt and 440,000 google scholar results and thousands of real climate scientists in the field. Atomsk’s Sanakan is wrong. Atomsk’s Sanakan just ignores the science publication work of REAL Climate Scientists.”
Re: “Observed warming trends and CMIP projections are scenario-dependent and highly uncertain beyond a few decades; top-of-atmosphere energy imbalance, feedbacks, and emission pathways make exact dates for 2–3°C or 4°C warming inherently approximate.“
None of the scenarios get to 3°C by 2050, as you’d know if you actually read the material cited to you (ex:this from IPCC 2021 figure SPM.8). But it’s clear you dodge evidence, as you’ve done across your sockpuppet accounts. Moreover, what Chuck originally cited and asked about was itself a projection. So it’s special pleading if you complain when others cite projections in response to show Chuck’s cited projection does not align with observed warming, nor with any other plausible projection. Your bias and reflective contrarianism is showing.
Re: “Therefore, any suggestion that CMIP outputs, the IPCC, or other frameworks are making a temperature prediction for 2050, 2100, or any specific future period is scientifically invalid; these models do not make such predictions.“
I said: “That’s in the range of other projections“. You responded with “prediction“, not ‘projection’. In messing up on the ‘projection vs. prediction’ distinction, you debunked your own point. Troll less, Data/Neurodivergent/Jim/etc., and actually learn the basics of what you discuss.
Bray 2009: “The IPCC provides the following operational definitions for the climate sciences: “A projection is a potential future evolution of a quantity or set of quantities” and “A climate prediction or climate forecast is the result of an attempt to produce an estimate of the actual evolution of the climate in the future, for example, at seasonal, interannual or long-term time scales.””
Piotrsays
– Chuck: “2+ 2 = 17.5. I don’t see how humanity survives this.”
– Atomsk: “This is incorrect. 2+2=4”
Multi-troll, having no problems with Chuck’s doomer claim, attacks instead Atomsk:
“You need to prove that allegation is true, science based, then show your work”
The onus of proof, my little Jimmy- is on the party that makes the more extreme, countering the scientific consensus claim. That party is called: “Chuck”
And no, Chuck’s link to …. some website that links …. NOT to a peer-review paper, but another website is NOT “a science-based” paradigm-changing proof.
Nigeljsays
Data, the German Physical Society must have used models with high to very high climate sensitivity. Because the IPCC RCP 8.5 worst case scenario is based on medium climate sensitivity and high emissions, if you read their reports, and it generates 3 degrees C by about 2060 at the earliest, so to get to 3 degrees by 2050 requires high climate sensitivity, assuming the same emissions level. But given the high emissions pathway is now unlikely due to a reducing rate of coal use, this also reinforces that high climate sensitivity would be required. And the high sensitivity climate models have problems easily googled and discussed on this website. So you are asking AS to prove something already proven, like night follows day.
If a model can’t predict the warming trend up until 2025 with at least reasonable accuracy then its unlikely to be able to predict temperatures beyond 2025, in the same way as if your car is unreliable its unlikely to suddenly spontaneously become reliable. Its self evident. It doesn’t need mathematical proof.
its authors rely in one of their warnings (that high climate sensitivity – about 5 K for atmospheric CO2 concentration doubling – is more likely than the lower limit of the considered range 2-5 K) on three sources listed as reference 11, namely:
a. Witkowski et al. (2024). Continuous sterane and phytane δ13C record reveals a substantial pCO2 decline since the mid-Miocene. Nature Communications, 15(1), 5192. https://doi.org/10.1038/s41467-024-47676-9
As regards the graphic from page 3 of the report suggesting the possibility of 3 K warming till 2050, it seems to be produced by certain Mr. or Ms. Gehlen, who was, according to reference (IV), inspired by a certain climate activist and book author, named Marcus Wadsak,
I have not checked if these references can be indeed construed the way presented in the graphic.
It is, however, remarkable that “further literature to the topic” includes, as item (VIII), also a publication by Zeller and Nikolov,
that comprises also active links to Shakun, Marcott and Nikolov as cited above, whereas although the pdf. version cited above is accessible from this “archive”, it comprises only references (I)-(V) and some links therefrom seem to be inactive / inaccessible. On the other hand, the reference (IV) in the pdf. version comprises also the source of Wadsak’s graphic
that is absent in the reference (IV) from the “archive” version.
Greetings
Tomáš
Nigeljsays
Tomáš Kalisz @ 25 Dec 2025 at 6:32 PM
Thanks for that information. I didn’t read the footnotes.
Its clear the German Geophysical Society are making quite big bold claims of 3 degrees C by 2050 given their graphic in the link posted by AS. To get to 3 degrees c by 2050 would require quite a massive leap in the decadal rate. I think Piotr said it would need to get to 0.65 degrees per decade which sounds correct.
AS seemed to be suggesting they are using discredited climate models. I couldn’t find a specific reference to this in the link he posted. But I thought they must be using the climate models that run very hot. In hindsight perhaps they could also be relying on something else related to the links you posted, but I doubt its James Hansen. He is predicting something like 0.45 degrees c per decade over the next couple of decades, which is way less than 0.65 degrees.
Its possible the GGS are just extrapolating the trend slope over the last 3 years which would be pretty stupid. Or perhaps they are relying on another source in one of the links you posted. I haven’t read all those. Its just a bit much to wade through and one paper is paywalled. And I’m already personally satisfied the GGS claim of 3 degrees by 2050 doesn’t sound credible, partly because its so much higher than the IPCC or even Hansen.
I do personally think climate change most likely accelerated around 2015 and this acceleration will likely significantly accelerate further, and that we are looking at future warming somewhere between what people like Mann and Hansen are predicting. This mainstream prediction is quite concerning enough without bothering about whether the extremists and speculators say, especially when like the GGS, they don’t bother to clearly state in their report how they arrived at 2 – 3 degrees by 2050. For all I know its from a science fiction novel.
But I do respect what Hansen says. He does back his claims with various suggested mechanisms and evidence although I lean a bit more towards the IPCC estimates.
Datasays
The Three Musketeers?
Concern Trolling with nothing to say that’s relevant, no Data to contribute, or anything scientific.
They’ll keep.
Chucksays
Knock it off. I’m not trolling. I’m looking for either verification or an explanation. And I’m not a sock puppet account, as someone suggested.
I’m not a regular poster these days, but what I posted here did get some great explanations, which I am reading now.
I’m not a scientist but I do occasionally have questions. Relax.
Susan Andersonsays
Chuck: I agree the obsession with labeling people is wasteful and often inappropriate. That’s not to say that these entities don’t exist, but using them to insult people here has taken over the conversation in a way which is often nasty and wrong.
However, as noted, 3C is projected (possible, even likely) by 2100, not 2050. I don’t know where you got that figure. Surviving it is problematic at best, but it’s not happening in 14 years.
Susan Andersonsays
Oops, 24 not 14 years (2050 – 2026). My bad.
Piotrsays
Susan to Chuck: “I agree the obsession with labeling people is wasteful and often inappropriate.
Except nobody “labelled” Chuck with anything. Nobody called _him_ “sock puppet account”, it’s the sock-puppet account that was called a “sock-pocket account”.
And to identify him as such, based on the 100s of earlier posts under various made-up name is calling “spade a spade”, if anything – a public service saving people here time on treating new sockpuppet handles as if they represented a new, open to arguments, person.
So your “labeling people is wrong” reply is misdirected – applies to the sock puppet account who resorts to labelling people as an unwitting admission of being incapable of disproving opponents arguments,
As for “Chuck” – by his fruits we shall know him. So far does not look good: he dramatically questions the future of humanity based on …. non-credible extreme numbers, and when these numbers are challenged, Chuck throws his original argument under the bus:
=========
Chuck: “ Knock it off. I’m not trolling. I’m looking for either verification or an explanation ”
Me: Sure, your:
Chuck: “ I don’t see how humanity survives this 3 C by 2050. 5 C by the end of the century!”
certainly sounds like … just a question by somebody who has no opinion on the matter.
And ended with the exclamation mark – that universal signal of a doubt … ;-)
================
To clarify: I’m not saying you’re trolling or a sockpuppet account. I’m saying Data and Jim are sockpuppets of Neurodivergent. You’re clearly not one of their accounts.
No doubt those 2 sockpuppets will soon leave, to be replaced by at least 1 new sockpuppet that posts with the same high frequency, posting style, idolization of Dr. James Hansen, failed criticism of the climate science community outside of James Hansen (ex: the IPCC), whiningabout ‘net zero by 2050’ not being enough, and so on. After all, they’ve been doing that for years across several rounds of sockpuppet accounts. The rest of us at least have the integrity to stick to the same account instead of using multiple accounts to spam, pretend others agree with us, bravely run from questions, etc.
Ron R.says
Piotr, chill out. C’mon, enough. Make your point calmly.
Piotrsays
– Chuck: “I don’t see how humanity survives this 3 C by 2050. 5 C by the end of the century!”
– Piotr: ” the current warming rate is below 0.3C per decade, not 0.64C.”
– Chuck: “And I’m not a sock puppet account, as someone suggested.”
– Piotr: “Nobody suggested _that._”
– Ron R.: ” Piotr, chill out. C’mon, enough. Make your point calmly.
=====
Good one, Ron! I didn’t know you are into deadpan. ;-)
Susan Andersonsays
Piotr: By writing a lengthy complaint which reveals you misread the meaning of what I wrote, you diminish your effectiveness. I keep my posts short for a reason. You left out this: “That’s not to say that these entities don’t exist, but using them to insult people here has taken over the conversation in a way which is often nasty and wrong.” On the whole, I trust you on science. It’s the insults which undermine your point(s).
I suggest you spend less time here. Find something local to do which helps more than extensive writing here, no matter how accurate.
Piotrsays
Susan Anderson 29 Dec “ On the whole, I trust you on science. It’s the insults which undermine your point(s).”
What insults? Neither I nor Atomsk used ANY insults toward Chuck – NOBODY dismissed Chuck by insulting him as “troll”, and Nobody called _him _ “sock puppet account”.
You jumped in with your support for Chuck, without BOTHERING to check whether his claims were true, And your response:
S: “ I agree the obsession with labeling people is wasteful and often inappropriate.”
sounds much more like you agreeing with …. you – Chuck said NOTHING about “obsession” – nor wasn’t he protesting ineffectiveness of it.
And when I pointed that Chuck mistook to him what was clearly addressed to the Multi-troll – you …. glossed over these facts, and used my proving my points with quotes to …. dismiss my post as “lengthy complaint “, and lectured me of misreading/ignoring? your real message:
Susan: “You left out this: “That’s not to say that these entities don’t exist, but using them to insult people here has taken over the conversation in a way which is often nasty and wrong.”
I misread/ignored nothing, quite the contrary – I have directly challenged it:
====
P: “to identify [sock-puppet as sock-puppet] based on the 100s of earlier posts is calling “spade a spade”, if anything – a public service saving people here time on treating new sockpuppet handles as if they represented a new, open to arguments, person.”
====
And I stand by it – life is too short to not call spade a spade. It SAVES time when we identify the new handle as the old sock-puppet, and when Atomsk. MARodger, BPL or me answer puppet’s specific claim – that’s not for the multitroll’s edification, but for the benefit of a non-scientist, as an immunization against similar claims repeated elsewhere.
As for your advise, “I suggest you spend less time here.” coming at the end of
a disappointing for me post (I believe you are better than it), we clearly don’t see eye to eye on that. So I suggest you do you, and I’ll do me.
Tomáš Kaliszsays
in Re to Atomsk’s Sanakan, 23 Dec 2025 at 7:23 AM,
The problem I see not only with James Hansen, DPG, DMG but also with other scientists who try to somehow alarm the public with respect to the present climate change – irrespective whether it is about a stronger or weaker “climate emergency” or, in some cases, about alleged lack thereof – is the circumstance that many of them seem to genuinely believe they are right and their opponents are wrong.
My former boss told me once that “patent attorney should not be inventive”. In other words, if the attorney tries to somehow improve or further develop the concept presented by an inventor by his or her own ideas, there arises a risk that the contribution may be, finally, rather harmful than favourable for the client. I am afraid that a scientist who becomes so strongly convinced about his or her truth that (s)he is willing to present his or her view(s) as the “right” science in public campaigns may be, in fact, still wrong. I am afraid that such scientists may, step-by-step, lose their ability to perceive hints that are contrary to their view(s), and thus progressively suffer from a self-strengthening confirmation bias.
As a member of the public who necessarily hears the loudest voices only, I am afraid that under the described circumstance when all these mutually contradictory views present themselves as a scientific truth, I tend to assess all of them with a deep scepticism, as potentially biased.
Anyway, I think that it may be better to live in an uncertainty than in a false certainty. Therefore, I would like to appreciate not only your efforts but also all critical analyses provided by the moderators and other commenters.
I wish you merry Christmas!
Greetings from Zlín, Czech Republic
Tomáš
Ron R.says
“Anyway, I think that it may be better to live in an uncertainty than in a false certainty”
i think it might not be a popular sentiment around here, and I apologize in advance to them, but not always. You ever heard of the term, “ignorance is bliss”. If you could choose to be happy or to know everything which would you choose? I know which I’d choose in a heartbeat (though it might be why we in the world have the problems we do).
True, some are happy and knowledgable but true happiness is a very rare gem.
To be honest, I do not believe that any human being can know everything. That is why I cannot answer your question; I simply cannot imagine that such a choice could be available. Should someone offer this choice to me, I would have, very likely, hardly trusted that it is a serious offer.
What makes a sense to me is a slight modification to this offer which may better fit the practical life. I am afraid that curiosity may act as a kind of a drug. If I seek an answer to a question, I tend to sacrifice lot of things that are usually linked to happiness, simply because I would have not been happy if I knew that I stopped asking before I tried everything in my power.
In my case, the disadvantage of this addiction is that with increasing age, my list of unresolved questions that I had to put on ice becomes longer and longer anyway, despite of the invested effort.
Greetings
Tomáš
Ron R.says
Tomáš, yeah. They say the more you know the more your realize that you don’t know. :/
Pete bestsays
It won’t be 3C by 2050 because the planet isn’t warming at 1C per decade but at o.2C which means by 2050 it would have warmed another 0.5C maximum making 1’95C which isn’t great. Even if CC has accelerated to 0.25C then it’s 0.6C per in 25 years.
Seems about right. We’re currently at ~1.4°C for the Paris Agreement’s longer-term level (the long-term trend, not the annual anomaly). And we’re warming at ~0.26°C/decade:
Forster 2025: “The rate of human-induced warming for the 2015–2024 decade is concluded to be 0.27 °C per decade with a range of [0.2–0.4] °C per decade). This agrees with the decadal trend in observed warming of 0.26 °C per decade (also calculated as a linear trend through 10-year periods – see Sect. 7.1).”
At around that rate we’re on pace to reach the Paris Agreement’s 1.5°C longer-term level by about 2029/2030, 2°C by 2045-2050, and 3°C by 2075-2090:
Which shows 1970-2010 0.18 C and 2010 to present (2025) a linear fit of 0.31 C per decade
Hansen’s reasoning is to found in various commentary articles.
We mentioned extrapolating the final rate estimate into the future (albeit only a few years), and that it is conceivable it might continue accelerating. Some think this was ill-advised, given that the central estimate for the most recent rate according to the given analyses is about 0.4°C/decade, quite a bit higher than expected and higher than most people believe.
using the Berkeley data and
The given analyses estimate the rate at about 0.043 ± 0.01 °C/year (0.43 ± 0.1 °C/decade), and those are sound computations but they are predicated on the assumption (or should I say “presumption”) that the signal follows our model exactly. …. When it comes to statistical models, no matter how useful they might be, George Box was right: they’re all wrong.
and
There’s a lot of good reason to believe that the rate isn’t as high as 0.4°C/decade. For my best estimate, I’ll say the rate is 0.33 -.1 +.2 °C/decade (i.e between 0.23 and 0.53, best guess 0.33).
If I could put words into Stefan and Grant’s mouths, is appears to me they do not believe it will be less than 0.30 C per decade warming in the near future.
As good as if not better than any other persons guess. Of course this is only statistics, and statistics are not reality. He’s right, it just “guessing”. All things being “equal” though 0.2C or less seems improbable now.
0.3C per decade warming, without any further acceleration (which cannot be ruled out scientifically) places the increase in warming from + 1.5C average the last 3 years (Hansen + multiple sources) to an 1880-1920 GISS Anomaly of +2.25 C by 2050.
Given the high degree of Unknowns though, I think it’s rash to completely rule out closer to +3.0 C anomaly by 2050 as anything could happen going forward we cannot safely predict. No one predicted the 2023-2024 rapid acceleration either. .
Whereas breaching 2C before 2040 is imminently plausible now. The joint DMG/DPG call makes clear that things are urgent even if their projections are on the higher end of what’s probable.
Re: “0.3C per decade warming, without any further acceleration (which cannot be ruled out scientifically) places the increase in warming from + 1.5C average the last 3 years (Hansen + multiple sources) to an 1880-1920 GISS Anomaly of +2.25 C by 2050.“
Nope, sockpuppet account. Thedocument in question used Paris Agreement targets. Warming relative to the pre-industrial baseline of 1850-1900 for the Paris Agreement is calculated using a 20-year mean to mitigate bias from outlier years (i.e. what you’re exploiting). That puts us at ~1.4°C, not yet 1.5°C:
– WMO: “Note that the 1.5°C level specified in the Paris Agreement refers to long-term level of warming inferred from global temperatures, typically over 20 years.”
– Kirchengast 2025: “Global surface air temperature change versus preindustrial level is a primary metric of global warming. Its 20-year mean serves as the indicator of the Intergovernmental Panel on Climate Change to monitor threshold crossings like of the 1.5 °C target of the Paris Agreement. […] The 20-year mean still stayed below 1.5 °C (1.39 [1.29–1.49] °C) but is set to cross this threshold in 2028 [2025–2032].”
So ~1.4°C combined with 0.3°C/decade would mean the Paris Agreement’s 2°C threshold would be crossed around 2045. That’s consistent with what I saidelsewhere and not near 3°C by 2050. Yet your sockpuppet account ‘Data’ baselessly claimed that: “~2°C by 2045-2050 is blatantly false and unfounded..” So you should talk with yourself to reconcile that difference with your sockpuppet; your eagerness to disagree and troll caused you to contradict yourself.
Re: “Given the high degree of Unknowns though, I think it’s rash to completely rule out closer to +3.0 C anomaly by 2050 as anything could happen going forward we cannot safely predict. No one predicted the 2023-2024 rapid acceleration either.“
The predictability of a longer-term trend exceeds that of a shorter term fluctuation. Hence why it’s easier to accurately predict a 1-to-1 ratio of heads-to-tails for 200 coin flips than for 10 coin flips.
Re: “The joint DMG/DPG call makes clear that things are urgent even if their projections are on the higher end of what’s probable.“
3°C by 2050 is not on the higher end of what’s probable. It’s not even probable; it’s extremely unlikely and undermined by evidence cited previously, such as cherry-picking models that overestimated warming through 2025. Wanting to urgently call people to action is not an excuse for promoting extremely unlikely scenarios without making it clear to the audience that they’re extremely unlikely. And yes, ‘extremely unlikely‘ is an appropriate term here, maybe even ‘exceptionally unlikely’. It’s ‘extremely likely’ and maybe even ‘virtually certain’ that 3°C won’t happen by 2050. That’s consistent with IPCC terminology and the uncertainty ranges for the IPCC’s projections:
It would be like if I told people it’s possible their plane flight explodes, without telling them how extremely unlikely that is. That would lead some people to behave like Chuck, saying: ‘I don’t see how plane passengers survive this! Someone help me out with this. Thoughts?‘.
Datasays
Chuck says 20 Dec 2025 at 7:56 PM
I don’t see how humanity survives this. 3 C by 2050. 5 C by the end of the century! Someone help me out with this. Thoughts?
You are right to be alarmed questioning how humanity survives that kind of world. The goal of the article I suspect.
Keep in mind the Mid-Century period (20-year averages covering roughly 2041–2060) on current SSP trajectories of SSP2-4.5 (Intermediate) and SSP3-7.0 (High GHG) the IPCC AR6 also gives broader warming ranges with the upper bounds of +2.5C to +2.6C respectively.
This implies that by around 2050, the multi-decadal average warming relative to 1850–1900 could lie somewhere in ~1.2 °C–3.0 °C (max @ SSP5-8.5), depending on how emissions evolve. These kinds of numbers are not definitive but estimated predictive ranges. The DPG/DMG as well uses projections out to 2050. They are not directly comparable.
A useful distinction here is between what AR6 actually showed and what this DPG/DMG statement is doing with recent observations. In AR6, the upper end of SSP5-8.5 already reached a potential ~3 °C in the 2042–2060 window, so a mid-century 3 °C outcome is not new within that scenario.
However, current global emissions are not tracking SSP5-8.5, and AR6 treated that pathway as a high-end stress test rather than a likely trajectory. The DPG/DMG statement instead extrapolates from recent observed warming, which necessarily includes short-term variability (ENSO, aerosol changes, ocean heat uptake), on top of the forced trend.
That makes the claim observationally motivated but not equivalent to being “on an SSP5-8.5 pathway”, and it does not resolve how much of the recent acceleration reflects transient natural or semi-forced factors versus a sustained long-term rate. Keeping that distinction explicit matters for interpretation.
Furthermore, the DPG/DMG statement itself is a call to policy makers for action. Of course they are emphasising the worst case top-end scenarios here. Which the Responsible Alpha journalistic article expands upon. Unfortunately they are not asking for anything new as far as action to solve the problem.
While it is still early days, to me this is another example of extrapolating the recent unexpected and not predicted 2010-2025 warming acceleration into the future. Will this acceleration rate be sustained? A good reason to keep one eye on what Hansen et al are suggesting is the underlying physics here.
My thoughts are we’ll have to wait for a while longer.
Re: “Keep in mind the Mid-Century period (20-year averages covering roughly 2041–2060) on current SSP trajectories of SSP2-4.5 (Intermediate) and SSP3-7.0 (High GHG) the IPCC AR6 also gives broader warming ranges with the upper bounds of +2.5C to +2.6C respectively.
This implies that by around 2050, the multi-decadal average warming relative to 1850–1900 could lie somewhere in ~1.2 °C–3.0 °C (max @ SSP5-8.5), depending on how emissions evolve.“
None of the IPCC’s warming scenarios reach 3°C by 2050, sockpuppet account; they’re all less than 3°C. That’s shown, for example, in this from figure SPM.8.
Re: “The DPG/DMG statement instead extrapolates from recent observed warming, which necessarily includes short-term variability (ENSO, aerosol changes, ocean heat uptake), on top of the forced trend.“
Extrapolating recent observed warming of ~0.26°C/decade would give 2°C by 2045-2050, consistent with observationally-constrained CMIP6 models, CMIP5 models, the IPCC, etc.:
– Forster 2025: “The rate of human-induced warming for the 2015–2024 decade is concluded to be 0.27 °C per decade with a range of [0.2–0.4] °C per decade). This agrees with the decadal trend in observed warming of 0.26 °C per decade (also calculated as a linear trend through 10-year periods – see Sect. 7.1).”
– IPCC Special Report, “Global Warming of 1.5°C”, Summary for Teachers: “It is stated that the global temperature has already increased by approximately 1.0°C. It says further that global warming is likely to reach 1.5°C between 2030 and 2052 if it continues to increase at the current rate. Find out the current warming rate.
[…] Solution : the current rate of warming is approximately 0.026°C per year.”
So it’s not 3°C by 2050. 3°C by 2050 instead comes from cherry-picking a small number of CMIP6 models that are known to overestimate warming, including warming up to 2025.
Re: “While it is still early days, to me this is another example of extrapolating the recent unexpected and not predicted 2010-2025 warming acceleration into the future. Will this acceleration rate be sustained?“
1) You haven’t shown statistically significant acceleration of global surface warming. That’s because there’s not statistically significant acceleration yet.
2) Acceleration wasexpected, despite not enough time passing for it to be statistically detectable at a predetermined threshold for statistical significance.
Again, none of this is being said for your benefit, since you’re a lost cause. It’s instead for those you’re trying to disinform.
Tomáš Kaliszsays
in Re to Atomsk’s Sanakan, 25 Dec 2025 at 11:36 AM,
I tried to show that the most alarming graphic on page 3 of the common call of the German Physical and Meteorological Societies seems to have a somewhat dubious origin. I have a plea to you:
If you have an access to primary sources that allegedly comprise the data forming (at least according to the reference (IV)) the basis for this alarming graphic, could you perhaps check if their interpretation in this strange graphic allegedly produced by certain Mr. or Ms. Gehlen (who is absent in the list of the authors at the end of the call) is correct?
To be honest, even though the equilibrium climate sensitivity were as high as 5 K for doubling of atmospheric CO2 concentration (as the authors of the common call are willing to accept), I still do not understand how this level of warming could be achieved already about the year 2100, as suggested by the said graphic.
Many thanks in advance for a comment and best regards
Tomáš
There’s not going to be an accurate figure/diagram that gets you to 3°C by 2050. I think you’re referring to the graph on page 3 of this. An accurate counterpart to that would be figure 1 of Kaufman 2022. But all the projections in that figure are below 3°C by 2050, similar to this from IPCC figure SPM.8. So again, what seems to have happened is people got 3°C by 2050 by cherry-picking a small number of CMIP6 models that are known to overestimate warming, including warming up to 2025.
Tomáš Kaliszsays
in Re to Atomsk’s Sanakan, 27 Dec 2025 at 6:39 PM,
(i) the references in the common GPS/GMS call do not seem to refer to any specific set of CMIP6 models,
(ii) the most alarming graphic on page 3 seems to be inconsistent even with other statements of this call,
(iii) there seem to be discrepancies even between the text of the common call
as published on the official DPG page and its pdf version you are referring to.
All these circumstances suggest that, unfortunately, both respectable scientific societies have not invested the necessary effort into editing the call thoroughly enough.
I am afraid that the editors simply failed in avoiding mutually conflicting and potentially misleading information. Personally, I really regret that two important societies representing German science demonstrated such a deficit of accuracy and thoroughness that have been traditionally considered as German virtues.
Greetings
Tomáš
Piotrsays
Chuck 20 Dec: “ I don’t see how humanity survives this. 3 C by 2050. 5 C by the end of the century! Someone help me out with this. Thoughts?”
Garbage in (Chuck’s +0.64C per decade), garbage out: (Multitroll: “You are right “) ?
Datasays
Reply to Piotr
Intentional quote surgery normally requires anaesthetic. That is not what I wrote, nor what I meant.
Piotrsays
Re Data’s 27 Dec insinuations
Put your money where your mouth is, Buttercup, i.e., show how in your response to Chuck:
====
– Chuck: “ I don’t see how humanity survives this. 3 C by 2050. 5 C by the end of the century! ”
– “Data”: ” You are right [to be alarmed questioning how humanity survives that kind of world]”
===============================
by “ that kind of world ” you …. did NOT mean Chuck’s “ 3 C by 2050. 5 C by the end of the century!“, but apparently some …. completely different kind of world (D: “ not what I wrote, nor what I meant. “)
Until then:
– Now stand aside!
– Data: Tis but a scratch!
– A scratch? Your arm’s off!
– Data: No, it isn’t. [Then, seeing his arm gone] I’ve had worse.
Nigeljsays
This is interesting: “My 2026 and 2027 global temperature forecasts. The best thing about predicting the near future is you don’t need to wait long to be wrong Zeke Hausfather Dec 21, 2025.” Refer:
It relates to Regarding “Data says 18 Dec 2025 at 9:31 PM on Hansens warming predictions for 2026 – 2027.
I haven’t read all this material in detail, and I have no idea yet who might be making the best predictions, and I avoid taking sides too much. I’m posting this ONLY because its relevant not to necessarily promote ZH.
I do instinctively find Hansen quite impressive in a general sense. He is a visionary and he considers the big picture very well. Not everyone has that talent. And I know I have provably good instincts. But I also know instincts can be WRONG, so I maintain a healthy scepticism of anything anyone says including Hansen. Otherwise you end up with out of control hero worship like Taylor Swifts “swifties” . Good grief I don’t want to end up like that.
I note that he plots a 2025 annual average while using “the prior year’s temperature, the latest monthly temperature” in his methods. Both 2025 and Dec2025 still have a few days to go.
The ERA5 numbers at Climate Pulse are showing Dec2025 to-date (+1.40°C) with a far lower anomaly than Sept-Nov2025 (+1.52°C). Using this 1850-1900 anomaly base, Dec2025 to-date is sitting higher than Jun-Aug2025 (+1.28°C), although not with the 1991-2020 base (Jun-Aug +0.47°C, Sept-Nov +0.69°C, Dec to-date +0.47°C).
The annual ERA5 SAT averages thus would run 2023 +1.48°C, 2024 +1.60°C, 2025 +1.47°C.
Mind, Zeke Hausfather isn’t using SAT (which is a bit more ‘acceleraty’ than the SAT/SST records.
The annual SAT/SST averages he plots run 2023 +1.46°C, 2024 +1.55°C, 2025 +1.44°C.
And just to add to the confusion, GISTEMP used by Hansen (SAT/SST) averages 2023 +1.45°C, 2024 +1.56°C, 2025-to-Nov +1.47°C. The full year GISTEMP 2025 will likely end up +1.46°C.
The various predictions (each given with large confidence intervals not shown by me) as reported by Hausfather, run for 2026 (& 2027 in brackets):-
Hansen….. … …. +1.47°C (+1.70°C)
Hausfather……… +1.41°C (+1.57°C)
UK Met Office… +1.46°C
I don’t actually see this 2026 =. +1.47°C quoted by Hausfather in Hansen’s ‘Global Temperature in 2025, 2026, 2027’ so I assume it is a mis-quote.
Hansen’s suggestion that the 12-month rolling temp will drop at some point due to the next La Niña to +1.4°C (previously sort-of implied back in March) before rising to the new record for 2027. That +1.4°C La Niña dip may then fit with the Hausfather’s 2026=+1.41°C although perhaps the 12-month rolling averages may drop further. The last seven months Apr-Nov25 actually average +1.40°C and what with the strange Sept-Nov warm SH wobble over and the autumn warm NH wobble looking rather muted, the next few months may dip down below +1.4°C.
Jimsays
MA Rodger says
“I don’t actually see this 2026 =. +1.47°C quoted by Hausfather in Hansen’s ‘Global Temperature in 2025, 2026, 2027’ so I assume it is a mis-quote.”
And nigelj ” you don’t need to wait long to be wrong”
–
Quoting Zeke: “Not to be outdone, James Hansen released his estimate that 2026 temperatures will also be around 1.47C in the GISTEMP dataset (albeit using a somewhat different 1880-1920 baseline)3, with the 12 month average dipping down to around 1.4C in the coming months before rising back up by year’s end.” https://www.theclimatebrink.com/p/my-2026-and-2027-global-temperature
I don’t think this is likely to be a “misquote” by Zeke so much as a reading or interpretation issue.
In the Hansen et al. paper, there is no explicit global temperature prediction for 2026. The +1.47 °C figure refers specifically to 2025: “Global temperature of +1.47 °C in 2025 relative to 1880–1920 is the 2nd highest in the period of instrumental data …”
Zeke’s phrasing (“2026 temperatures will also be around 1.47 °C”) appears to be an extrapolative paraphrase rather than a value stated by Hansen et al. Direct quotation seems the safer and clearer approach here.
Addendum (clarification)
Hansen et al. distinguish carefully between calendar-year global mean temperature anomalies and the 12-month running mean. The +1.47 °C value refers to the 2025 annual mean. The subsequent statement that temperatures “should decline for the next few months, reaching a minimum about +1.4 °C” refers specifically to the evolution of the 12-month running mean, not to an annual average for a future year.
Describing this as a “12-month average” or associating it with a specific calendar year risks conflating these two distinct quantities.
Jimsays
Nigelj says
22 Dec 2025 at 2:46 PM
I haven’t read all this material in detail, and I have no idea yet who might be making the best predictions, and I avoid taking sides too much. …………… Otherwise you end up with out of control hero worship like Taylor Swifts “swifties” . Good grief I don’t want to end up like that.
You know, everyone can see what you say.
Ron R.says
Thanks Nigel.
ZH, “The best thing about predicting the near future is you don’t need to wait long to be wrong”
Refreshing. In this narcissistic world to be humble enough to admit one’s own imperfections is quite rare. More of that.
It is quite common. More common that you chaps seem to be aware of. The prevailing climate here isn’t real world. Spread your wings.
Susan Andersonsays
Ron R. Excellent. Thanks for the link.
Ron R.says
Happy New Year all.
zebrasays
Ron, I have this question about “regrets”:
If you had never done any of those things you regret, who would you be?
(I mean, if you are going to reference Watts, you have to be prepared to encounter those kinds of profundities, right? ;-) )
I liked the video, especially the stars. I haven’t seen them in a long time; it’s actually the only thing I’ve got on my one-last-time list. Crawling out from a bag, standing in the snow peeing, looking up… pretty much covers what he was talking about.
Ron R.says
Zebra, good question. Have to think about that for awhile. Not the current me, though. Of all the many paths I could have taken I would hope I’d have chosen a better path. Who wouldn’t? Be a better version of me. Might have saved myself a lot of anguish. But then I might not have learned as much. That last part might be what your driving at.
But then again, would I rather know or be happy?
Watts was an environmentalist. But he was also a Zen Buddhist. As far as I know, Zen Buddhism’s bottom line is that you have to discover the answers for yourself. You can correct me if I’m wrong, my friend.
Ron R.says
Zebra, I muffed that up. You understand. I have more evolving to do. :/
zebrasays
Ron,
I will try to reply further next month. For me, it’s a very interesting topic; Watts wrote specifically on that “who am I?” trying to show the difference between “Eastern Thinking” and “Western Thinking”. And it all ties in with modern physics and even climate science.
Oh and you motivated me to check wiki-p on Watts; lots of interesting details I had no idea about. I just have this old paperback of his turning yellow on my bookshelf; you also motivated me to get it down after all these decades and check out the pages I had bookmarked.
Piotrsays
Ron R. “Refreshing. In this narcissistic world to be humble enough to admit one’s own imperfections is quite rare”
You may be reading more into it than there is. ZK has admitted nothing, certainly not “his own imperfections”. He wouldn’t offer his prediction if he did NOT think that the odds of him being right are substantially higher than him being wrong. As such – this is neither a proof of any particularly “refreshing humbleness”, nor is as rare as you think it is.
Datasays
What about Hansen et al “warming predictions” for 2026 – 2027?
First what of his 2025 “predictions”, they count now already. These suggest that Hansen’s “acid test” proved valid. And his “predictions” (couched in the unknown of how the typical 0.5C swing in natural variation of ENSO would unfold) have proven quite correct-if not at least they confirm his analysis is stronger now 2 years ago.
Showing an actual +1.47C anomaly, a drop of only 0.1C off the 2024 GMST (GISS) of 1.57c
Further back-
Two years ago (29 March 2024) we projected that global warming in the then-ongoing El Nino
would rise much more than in prior El Ninos, raising global temperature to at least +1.6°C, and
that temperature after the El Nino would fall only to +1.4°C (see Fig. 2). https://www.columbia.edu/~jeh1/mailings/2025/GlobalTemperaturePrediction2025.12.18.pdf
Actual 2024 was 1.57C and after el nino this year 2025 is +1.47C and falling. Quite close given the constraints.
Next for some more context see how Hansen et al differentiate their findings from others “predictions” eg Zeke H and many others.
IPCC’s approach to climate analysis came to be dominated by use of global climate
models (GCMs) for climate simulations of the past 1-2 centuries. We have taken a complementary
approach, placing comparable emphasis on paleoclimate data, GCM modeling, and modern
observations of climate processes, as described in our three main papers published in the past
decade: (1) “Ice melt, sea level rise and superstorms,”4 (2) “Global warming in the pipeline,”5 and
(3) “Global warming has accelerated.”6 The third of these, published last week, was long, as it tied
all three together, especially via its Supplementary Material (SM),7 which usually houses only
secondary material. Here is a link to the Abstract + Paper + SM as a single document. Below, we
first provide a plain language summary of the three principal conclusions of this paper and then
address questions raised in the media by kibitzers.
That article, need to be read in full and understood in context of those peer-reviewed papers,
See- The question is: how much further is climate sensitivity altered by the cloud feedback? Let’s consider
three cases: (1) negligible cloud feedback, gcl ~ 0, (2) modest cloud feedback, gcl ~ 0.1, and large cloud
feedback, gcl ~ 0.25. These three cases yield equilibrium climate sensitivities of 2.4°C, 3°C and 4.8°C
(see equation 4), respectively. The observed change of Earth’s albedo during the past 25 years allows
unambiguous discrimination among these three cases: the large observed decrease of Earth’s albedo
rules out the zero and moderate cloud feedbacks. The cloud feedback is large, implying, with a high
degree of confidence, that real-world climate sensitivity is much higher than 3°C for doubled CO2. https://www.columbia.edu/~jeh1/mailings/2025/CloudFeedback.13May2025.pdf
And again we see Hansen’s repeated accurate and scientifically valid “prediction” for 2025.
The Acid Test: Global Temperature in 2025
James Hansen and Pushker Kharecha 20 February 2025
An “acid” test of our interpretation will be provided by the 2025 global temperature:
unlike the 1997-98 and 2015-16 El Ninos, which were followed by global cooling of more than
0.3°C and 0.2°C, respectively, we expect global temperature in 2025 to remain near or above the
1.5°C level. https://www.columbia.edu/~jeh1/mailings/2025/Acid.Test.20Feb2025.pdf
Best read in full and understood. The 2025 result is +1.47C – which is “near” the 1.5C level. This preliminary “acid test” has been passed. A drop on 2024 el nino of only 0.1C as opposed to the historical norm of 0.3C to 0.4C fall in GMST the following year / period due to ENSO. Goes to some confirmation of Hansen’s larger “theory” of what is happening now, and why.
This work and analysis by Hansen et al spanning 6 years now goes far beyond anything Zeke H has to say on global temp anomalies. Instincts have nothing to do with it. It’s good science and excellent reasoning. The 2025 temp results offer strong conditional support that Hansen’s analysis is correct. Being mindful that anything might happen with “so-called natural variation” in the meantime his 2026 and 2027 predictions offer the opportunity for further confirmation his theory is on solid scientific ground, once the Data is in.
See- Fig. 4. NCEP CFS.v2 Nino3.4 forecast (issued 15 December)4 Global warming projection. Assumption of at least a moderate El Nino beginning in 2026
leads us to the projection in Fig. 5, with global temperature reaching a minimum at or above
+1.4°C within several months and then rising to a record global temperature of about +1.7°C in
2027. This new record will occur only four years after the 2023 El Nino, so additional,
underlying, global warming at the accelerated rate of 0.31°C per decade is only about 0.1°C https://www.columbia.edu/~jeh1/mailings/2025/GlobalTemperaturePrediction2025.12.18.pdf
Killiansays
Soooo… anyone notice that my 2015 #theory on #ElNino effects on #ASI is still intact, unbroken after ten years?
Datasays
Reply to Killian
Sounds reasonably plausible. Pity a paper wasn’t published on it.
The other issue (I think you may have flagged too Killian) about global warming will “soon” show itself to be disrupting the ENSO pattern. The cycle is being disrupted now and this is clearly being observed. La Nina in particular is showing as being affected where decline in temps and other conditions are shifting. Time frames are contracting, ot at least appear so. In time this too will be undeniable. And change everything surrounding the “so-called natural variation” tool when things do not add up nor reflect the expected conditions based on models and typical consensus thinking.
My observation based opinion which I predict will eventually be reflected in the real science. I expect before 2030 there should be some papers out about this shift. Along with many more about albedo aerosols and cloud feedbacks and ongoing warming acceleration no matter what happens with ENSO or emissions here on in. Ideas first, the data will follow.
Barry E Finchsays
Started affecting ENSO in 1995. It started 1995. By 2012 the wind was a massive 30% (1 metre / second) stronger than pre-1995. I’ve not yet found post 2012 so I don’t know whether the big 2015/16 El Nino was the end of the massive 17 to 20 year Trade Wind surge. ENSO is an utterly-vast feature of Earth’s surface-air.
—————-
Quote: “Atlantic warming turbocharges Pacific trade winds Date: August 3, 2014 Source: University of New South Wales. New research has found rapid warming of the Atlantic Ocean, likely caused by global warming, has turbocharged Pacific Equatorial trade winds. Currently the winds are at a level never before seen on observed records, which extend back to the 1860s. The increase in these winds has caused eastern tropical Pacific cooling, amplified the Californian drought, accelerated sea level rise three times faster than the global average in the Western Pacific and has slowed the rise of global average surface temperatures since 2001. It may even be responsible for making El Nino events less common over the past decade due to its cooling impact on ocean surface temperatures in the eastern Pacific. “We were surprised to find the main cause of the Pacific climate trends of the past 20 years had its origin in the Atlantic Ocean,” said co-lead author Dr Shayne McGregor from the ARC Centre of Excellence for Climate System Science (ARCCSS) at the University of New South Wales.”
—————-
Quote: “The record-breaking increase in Pacific Equatorial trade winds over the past 20 years had, until now, baffled researchers. Originally, this trade wind intensification was considered to be a response to Pacific decadal variability. However, the strength of the winds was much more powerful than expected due to the changes in Pacific sea surface temperature. Another riddle was that previous research indicated that under global warming scenarios Pacific Equatorial Trade winds would slow down over the coming century. The solution was found in the rapid warming of the Atlantic Ocean basin, which has created unexpected pressure differences between the Atlantic and Pacific. This has produced wind anomalies that have given Pacific Equatorial trade winds an additional big push. “The rapid warming of the Atlantic Ocean created high pressure zones in the upper atmosphere over that basin and low pressure zones close to the surface of the ocean,” says Professor Axel Timmermann, co-lead and corresponding author from the University of Hawaii. “The rising air parcels, over the Atlantic eventually sink over the eastern tropical Pacific, thus creating higher surface pressure there. The enormous pressure see-saw with high pressure in the Pacific and low pressure in the Atlantic gave the Pacific trade winds an extra kick, amplifying their strength. It’s like giving a playground roundabout an extra push as it spins past.” Many climate models appear to have underestimated the magnitude of the coupling between the two ocean basins, which may explain why they struggled to produce the recent increase in Pacific Equatorial trade wind trends. While active, the stronger Equatorial trade winds have caused far greater overturning of ocean water in the West Pacific, pushing more atmospheric heat into the ocean, as shown by co-author and ARCCSS Chief Investigator Professor Matthew England earlier this year. This increased overturning appears to explain much of the recent slowdown in the rise of global average surface temperatures. Importantly, the researchers don’t expect the current pressure difference between the two ocean basins to last. When it does end, they expect to see some rapid changes, including a sudden acceleration of global average surface temperatures. “It will be difficult to predict when the Pacific cooling trend and its contribution to the global hiatus in surface temperatures will come to an end,” Professor England says.”
—————-
Recent intensification of wind-driven circulation in the Pacific and the ongoing warming hiatus
Nature Climate Change 4, 222–227 (2014) doi:10.1038/nclimate2106 Received 11 September 2013 Accepted 18 December 2013 Published online 09 February 2014 Corrected online 14 February 2014
Matthew H. England, Shayne McGregor, Paul Spence, Gerald A. Meehl, Axel Timmermann, Wenju Cai, Alex Sen Gupta, Michael J. McPhaden, Ariaan Purich & Agus Santoso
Piotrsays
– Killian: ” Soooo… anyone notice that my 2015 #theory on #ElNino effects on #ASI is still intact, unbroken after ten years?”
– Data: “Pity a paper wasn’t published on it.”
Ouch. Et tu, Multi-troll, contra me? ;-)
Soooo …. why didn’t you publish it, Killian?
Jimsays
Reply to Data (re Killian’s comments)
There is a growing literature examining how ENSO behaviour may evolve as the background tropical Pacific warms, including potential changes in amplitude, duration, spatial structure, and mean state. Most of this work is based on modelling experiments rather than clear observational detection, and there is still no consensus that a distinct regime shift has yet emerged.
One important distinction is between a theory remaining internally consistent and the climate system entering a new, detectable regime. ENSO variability is now superimposed on a warmer baseline, which alters impacts even when the underlying oscillation remains recognisable. For example, weak La Niña events no longer produce the same global cooling as in past decades, simply because the background climate state has shifted.
Model results remain mixed. Some simulations suggest increased ENSO variability or extremes under warming; others show reduced variability, altered periodicity, or transitions toward El Niño–like or La Niña–like mean states under stronger forcing. These divergent outcomes largely reflect sensitivity to processes that remain poorly constrained, including fine-scale ocean mixing, stratification, air–sea coupling thresholds, and nonlinear feedbacks.
The key issue, therefore, is not whether familiar modes persist, but whether they continue to operate in the same way as the climate warms. At present, models are better suited to exploring plausible regimes and risk envelopes than to confirming specific outcomes or timelines. That argues for caution in treating continuity of past behaviour as confirmation, rather than as something that still needs to be tested against a changing background state.
For those interested in the current state of the science, there are several recent reviews and modelling studies exploring ENSO sensitivity to mean-state warming, nonlinear regime behaviour, and limits to detectability in the observational record.
Jim, during the period ~1970-2014 oft cited as a trend of +0.180 degrees / decade the La Nina and ENSO-neutral years both had a pretty-obvious trend of +0.165 degrees / decade (with the ENSO-neutral being a warmer trend line of course and I recall 0.13 degrees warmer but don’t quote me)
with the slack taken up by El Nino years warming at +0.20 degrees / decade until 1995 and then at +0.23 degrees / decade 1995 to 2012 but it was spotty and I used calendar years (2 years per El Nino).
I made that plot on 11×17 paper in 2013 and intended to do it again using El Nino periods instead of calendar years. At https://www.youtube.com/watch?v=agKayS6h6xA 21:38 to 23:20 colour-coded pictorial of GMST anomaly 1976-98 to 1999-2012 and wind explanation.
Mr. Know It Allsays
The sun is now the highest it will get at Vostok Station, Antarctica. The record high ever recorded is apparently 6.8 F, but it is forecast to be 8 to 10 F in a day or 2.
Mr. KIA. Thanks. It snowed here so I pushed snow until 22:30 because it’s scheduled to be concrete by this morning.
Piotrsays
KiA – “ the interior of Alaska has had a decent cold spell for the past couple of weeks and it seems to be continuing”
And you are telling us this because ….?
We have explained to you the difference between local weather and global climate many times already, haven’t we?
“NCAR has been operated since its inception by the not-for-profit University Corporation for Atmospheric Research, or UCAR, through a cooperative agreement renewed through a competitive process and extensive review every five years. UCAR comprises 129 member institutions from across North America, all of which offer research and education programs in the atmospheric or related sciences. Along with carrying out administrative tasks for NCAR, UCAR manages a set of smaller programs that carry out education, training, field program support, and other activities related to the Earth and atmospheric sciences. Thousands of scientists from across the world are involved with NCAR and UCAR in myriad ways.”
Lots more at link …
—
The current article is also useful: Improving indoor air quality might save your life. Cost-effective ways exist to improve your indoor air quality that will reduce your COVID and flu risk, lower your cancer and lung disease risk, and eliminate headaches and sleepiness caused by poor ventilation.https://yaleclimateconnections.org/2025/12/improving-indoor-air-quality-might-save-your-life/
Steven Emmersonsays
Thanks, Susan. It’s good to see such opposition.
I was a senior research software engineer in UCAR’s Unidata program for 35 years.
Needless to say, this Administration’s desire to dismantle NCAR is insane, IMO. To use a farming metaphor, it’s like eating one’s seed corn.
Barton Paul Levensonsays
Gavin-san,
I looked up the GISS page on aerosol optical depth, and found that their time series ends in 2012. I was able to extend that to 2019 with Miller’s (2021) data. Is there any update through 2024?
Looking around recent output about 2026 estimates/predictions my thinking is essentially how the forecasting centres themselves would phrase it: Near-term central estimate for 2026 GMST: ~1.4–1.5 °C above a pre-industrial baseline (≈1850–1900; very close to 1880–1920 once adjusted).
Best current conservative midpoint: ~1.45 °C. The ENSO wildcard: is still unresolved for mid-/late-2026. If conditions remain neutral or La Niña-leaning, the year likely stays just under 1.5 °C. If a moderate El Niño unexpectedly emerges sooner, the same underlying forced signal would almost certainly push the annual mean over 1.5 °C again, as we’ve just seen in 2023-2025.
Crucially — and this is often missed in public framing I see — nothing dramatic needs to “change” physically for that to happen. It’s the same elevated baseline plus interannual variability riding on top. General analysis shows Hansen’s 2026-2027 predictions are plausible.
On CO₂, my instinct is also mirroring general analysis There’s no serious scenario in the mainstream energy / emissions outlooks (IEA, Global Carbon Project, NOAA trend extrapolations) that shows anything other than another record atmospheric CO₂ level in 2026. The uncertainty is rate of increase, not direction. Adding weight to a continued warming acceleration above recent decades.
Difference in any of these short term annual predictions are of little importance. It’s the longer term sustained trends that matter more. But people can’t help themselves so here we are, still “arguing debating” the drivers of the 2023-2025 acceleration on top of the 2010 to 2025 acceleration of warming. There is no agreement, there is no consensus still. Real Climate has still not concluded it’s initial questioning of why this happened. It appears to have no opinion what caused the spike in warming in 2023-2024.
Frankly, I’m not sure it matters anyway. Secondly, we often have fake pronouncements online like this anonymous one- claiming to accurately speak for climate institutions, while offering zero evidence or qualified references to support it.
Atomsk’s claim is nonsense This statement does not correspond to anything the IPCC or CMIP system publishes. There is no evidence, no data nor analysis provided to prove this is accurate, or even close. It’s not a valid interpretation — it’s fabrication by compression.
Any statement like “2°C by 2050” without an explicit SSP and averaging window is not an IPCC result. Neither CMIP5, CMIP6, nor AR6 state that we are “on pace” for 3°C by 2075. That framing collapses multiple scenarios, ignores averaging periods, and replaces assessed ranges with an unsupported point estimate.
This “claim” by Atomsk’s Sanakan is not in AR6, not in CMIP, and not in any IPCC table or figure. It’s a personal extrapolation rhetorically attributed to the IPCC. It’s standard fluff from anonymous contributors trying to sound sciency and authoritative when they are not
Hansen is doing something quite different and this matters. Hansen’s recent work is explicitly outside the CMIP consensus frame. Key differences are:
He states physical mechanisms (aerosols, ocean heat uptake)
He makes falsifiable near-term predictions
He does not pretend CMIP means are observations
He separates scenario uncertainty from physics uncertainty
You can disagree with Hansen — but he is doing science, not rhetorical synthesis. While the “consensus” commentators are doing authority signaling, not scientific climate modelling. It’s useful to spot the difference.
Piotrsays
Hansen is doing science, not rhetorical synthesis.
… pontificates Multitroll “Data”, who himself is doing no science, only empty rhetorics?
“While the “consensus” commentators are doing authority signaling not scientific climate modelling. ”
… and so we are on the same page – how many climate models have YOU designed?
And what’s that authority signaling you speak of – something like YOU trying to gain credibility by associating yourself with the authority of Hansen?
Pretty typical of your disinformation tactics across your sockpuppet accounts. Hansen doesn’t need you to continue trying to mislead people to prop him up.
Re: “Atomsk’s claim is nonsense This statement does not correspond to anything the IPCC or CMIP system publishes. There is no evidence, no data nor analysis provided to prove this is accurate, or even close. It’s not a valid interpretation — it’s fabrication by compression.“
Nope since, for example, this was provided at the link the sockpuppet account willfully left out:
This is a further illustration of how the sockpuppet is deceptive across their accounts.
Piotrsays
Chuck: “ Knock it off. I’m not trolling. I’m looking for either verification or an explanation ”
Sure, your:
“ I don’t see how humanity survives this 3 C by 2050. 5 C by the end of the century!”,
certainly sounds like … just a question by somebody who has no opinion on the matter.
Particularly the highlighted part.
And then the exclamation mark – that universal signal of a doubt … ;-)
Chuck: And I’m not a sock puppet account, as someone suggested.
Except no one suggested _that_. The sockpuppet is the multi-troll you may know from the last month or so as: “Data”, “Jim, “Mo Yunus”,”Neurodivergent”. “Miell”-backwards, “Jim Hansen”-backwards. And dozens? hundreds? of other names from the months and years before. .
So nobody said that you ARE the sock-puppet, but merely that you are being USED by one:
Sockpuppet “Data” first butters you up: You are right to be alarmed questioning how humanity survives that kind of world”
– and then uses YOU as an implied ally in attacking his/her/its opponents:
Sockpuppet “Data”: First their comment [YOUR] “global warming could reach 3°C above pre-industrial levels by about 2050”
and follows with a long post, brimming with the supposed numbers, quotes, and sources – – all to HIDE the fact that he CAN’T prove YOU right: he can’t show the 0.64C per decade warming required to achieve YOUR: 3°C above pre-industrial levels by about 2050”.
The point of “flooding the zone” with his, ehem, material is that the opponents would be tied down disputing details, while the real audience – people like you – would take quantity for quality (“there is no smoke without a fire – he couldn’t invent, or misrepresented all these, right?”).
Particularly, if the reader had been already plied to be receptive to his message
with compliments ( “You are right to be alarmed” and with a sympathy as a fellow target of unfair criticism from the … trolls.
P.S. If you really haven’t expressed yourself well, and in fact you were just “ looking for either verification or an explanation ” then the answer is
“No, there are no reliable data to expect that at the current warming rate we will reach 3 C by 2050. 5 C by the end of the century!“, because the current warming rate
is below 0.3C per decade, not 0.64C.”
The situation is dire enough at the real warming rate, so no need to inflate it so much. Particularly that overexaggerating comes with the price – does not help the case, but actually harms it – the overexaggerated claims can, and are, used by fossil-fuel interests to throw the baby with the bathwater – to discredit ALL the climate science by associating it with very extreme claims that the science questioned: “ how can we believe ANYTHING you say when you predicted 3C warming by 205o “?
Thus if the doomers didn’t exist – the deniers would have to invent them. I divide the doomers into 3 categories:
1) false-flag operating denier trolls (without world’s dependence on fossil fuels – gone are the trillions from their exports, and with that
the economy, and therefore the regimes and the ability to finance wars/terrorism of the petro-states (Russia, Iran, Saudi Arabia, etc.)
2) those who don’t care about humanity and climate change – it’s all about them, about their ego ( if I, a scientific ignorant, can see what the top climate scientists failed, or refused, to see – then I must be really, really smart and virtuous)
3) well-intentioned individuals, who are unwittingly playing straight into the hands of the two above categories.
Chucksays
*P.S. If you really haven’t expressed yourself well, and in fact you were just “ looking for either verification or an explanation ” then the answer is*
Look, I’ve been visiting this site for a long time and I occasionally have questions. To imply anything other is ridiculous. You’re reading a lot into a simple post that requires one answer. Not some diatribe about trolls and me being used as a vehicle for some nefarious purpose. I’m very familiar with some of the trolls on this site and have complained about them often enough.
I’m not a scientist, just a musician. I’ll try to be more careful next time.
“The trouble with AI tools is that they seem to “exploit cracks in the architecture of human cognition,” … The human brain likes to conserve energy and will take available shortcuts to do so. “It takes a lot of energy to do certain kinds of thought processes,” Requarth told me; meanwhile, “a bot is sitting there offering to take over cognitive work for you.” … | “Chatbots are engineered to take advantage of this human tendency by offering compelling answers to any query, even if many of those answers are false or misleading.”
“Three years into the AI boom, an early picture of how heavy AI use might affect the human mind is developing. For some, chatbots offer emotional companionship; others have found that bots reinforce delusional thinking (a condition that some have deemed “AI psychosis”). The LLeMmings, meanwhile, are beginning to feel the effects of repeatedly outsourcing their thinking to a computer.”
“this data-center campus, far from complete, already demands more than 500 megawatts of electricity to power these calculations—as much as hundreds of thousands of American homes. When all the data centers in New Carlisle are built, they will demand more power than two Atlantas.
“The amount of energy and money being poured into AI is breathtaking. Global spending on the technology is projected to hit $375 billion by the end of the year and half a trillion dollars in 2026. Three-quarters of gains in the S&P 500 since the launch of ChatGPT came from AI-related stocks; the value of every publicly traded company has, in a sense, been buoyed by an AI-driven bull market. To cement the point, Nvidia, a maker of the advanced computer chips underlying the AI boom, yesterday became the first company in history to be worth $5 trillion.”
“It’s clear that AI is both drowning out and obscuring other stories about the wobbling American economy. That’s a concern. But even worse: What if AI’s promise for American business proves to be a mirage? What happens then? …. | For now, money is still pouring into the AI industry. But there’s also something circular about these investments.” …. | The biggest lesson of the past two decades of Silicon Valley is that Meta, Amazon, and Google—and even the newer AI labs such as OpenAI—have remade our world and have become unfathomably rich for it, all while being mostly oblivious or uninterested in the fallout. They have chased growth and scale at all costs, and largely, they’ve won. The data-center build-out is the ultimate culmination of that chase: the pursuit of scale for scale itself. In all scenarios, the outcome seems only to be real, painful disruption for the rest of us.”
“generative-AI applications in particular can be orders of magnitude more energy-intensive than the predictive-AI applications that came before. “We still don’t appreciate the energy needs of this technology,” OpenAI CEO Sam Altman said in January at Davos. “There’s no way to get there without a breakthrough.” In the meantime, tensions over data centers’ water use are cropping up not just in Arizona but also in Oregon, Uruguay, and England, among other places in the world.”
“With more than 8,000 data centers whirring all around the world and venting heat, and many more on their way, that optimism may come off as nothing more than faith: Technology has gotten us into this predicament; perhaps technology will get us out of it.” [more tech bro evangelism – all for me, none for thee – aka socializing risk while privatizing profit – and the delusions about immortality – wow1]
Nigeljsays
Something interesting on direct air capture of CO2, with calculations which show just how much electricity it may need:
Nigel: referring to an ” …and Then There’s Physics” article calculations of electricity needed for [direct air capture of CO2]: A key point is that given an atmospheric concentration of 400 ppm and a temperature of 300K, it takes a minimum of 19505 J to remove 1 mole of CO2.
How have they come up with these precisely looking (five significant digits??) calculations?
To what it relates? It looks like some thermodynamic concentration of atm. CO2. What for?
Without limitless free energy – no sane person would propose it as a cost effective way of DAC.
And if I instead plant a tree and during its life it sequesters 1 ton of CO2 in its wood – what would I need their “4.43 x 10^8J” for?
MA Rodgersays
Piotr,
The energy-powered DAC takes a shed-load of energy. The tree-powered DAC requires massive land area.
Maybe seaweed DAC is the answer!
Piotrsays
MA Rodger “Maybe seaweed DAC is the answer!
As with other climate solution, there is no seaweed, I mean, silver bullet.
DAC from reforestation, could be complemented by DAC from seaweed, complemented _if_ we could figure out the right place and approach that would work by the iron fertilization (the early 2000s mesoscale experiments poured cold water on John Martin’s quip “Give me a half a tanker of iron and I’ll give you the next ice age”), complemented by DAC from improved soil management, complemented by DAC via enhancement of geological uptake (CO2 taken up by weathering of carbonate and silicate rocks).
But the take home message – DAC should be used to mop up the last few% of the CO2 emissions that were “the highest hanging fruit” for Co2 emission reduction, but most of the work on the way to net zero has to be done by reductions in emissions.
Nigeljsays
Piotr,
Thentherewasphysics commentary on DAC: “A key point is that given an atmospheric concentration of 400 ppm and a temperature of 300K, it takes a minimum of 19505 J to remove 1 mole of CO2.”
Piotr said: “How have they come up with these precisely looking (five significant digits??) calculations? To what it relates? It looks like some thermodynamic concentration of atm. CO2. What for?”
Nigel: I was wondering myself. I simply don’t know enough physics to sort it out. I asked Microsoft copilot:
“In relation to DAC (direct air capture of CO2) someone made this statement. “A key point is that given an atmospheric concentration of 400 ppm and a temperature of 300K, it takes a minimum of 19505 J to remove 1 mole of CO2.” Is this correct and how was it derived.”
Copilot: Yes, that number is essentially correct, and it comes straight from basic thermodynamics of mixing/separation.
(unfortunately the copy and paste is unable to properly show some of the equations but if you ask the nice friendly copilot I assume it will give you the more readable version). Anyway here it is:
———————–
1. Where the 19,505 J/mol comes from
For an ideal gas mixture, the minimum reversible work to separate one component from a mixture at constant temperature and pressure is given by the change in Gibbs free energy associated with “un-mixing” that component.
For CO₂ in air at mole fraction x, the minimum work per mole of CO₂ is
W_{\mathrm{min}}=RT\ln \left( \frac{1}{x}\right)
at temperature T, where R is the gas constant. This is standard in treatments of gas separation and CO₂ capture thermodynamics.
Plug in the numbers:
– Gas constant:
R=8.314\ \mathrm{J}\, (\mathrm{mol^{\mathnormal{-1}}}\, \mathrm{K^{\mathnormal{-1}}})
– Temperature:
T=300\ \mathrm{K}
– CO₂ in air:
x=400\ \mathrm{ppm}=400\times 10^{-6}=0.0004
First compute RT:
RT=8.314\times 300\approx 2494\ \mathrm{J/mol}
Then the logarithmic term:
\ln \left( \frac{1}{x}\right) =\ln \left( \frac{1}{0.0004}\right) =\ln (2500)
Approximate:
\ln (2500)=\ln (25)+\ln (100)\approx 3.219+4.605=7.824
Now multiply:
W_{\mathrm{min}}=2494\times 7.824\approx 19,500\ \mathrm{J/mol}=19.5\ \mathrm{kJ/mol}
So the quoted value 19,505 J per mole of CO₂ at 300 K and 400 ppm is consistent with the standard thermodynamic minimum.
2. What assumptions are baked into this
This result assumes:
– Ideal gas behavior and ideal mixture (no interactions beyond ideal).
– Isothermal, isobaric, reversible separation.
– Initial state: CO₂ in air at 400 ppm.
– Final state: pure CO₂ at the same temperature and pressure.
In that ideal limit, the minimum separation work equals T\Delta S (or \Delta G, since it’s constant T,p), which for ideal mixtures gives exactly the RT\ln (1/x) dependence you see above.
In practice, real DAC systems require several times this minimum because of irreversibilities, sorbent/regeneration losses, pressure drops, etc. Literature values for the theoretical minimum for air-capture are in the same ballpark (~0.2–0.5 GJ per tonne CO₂ ≈ 4.5–11 kJ/mol), depending on how the process is defined and what concentration you’re separating to/from; 19.5 kJ/mol is the strict thermodynamic limit for going from 400 ppm directly to pure gas at the same T and p.
If you’d like, we can extend this to:
– compare that minimum to heat/electricity usage of actual DAC plants, or
– redo the derivation fully from the entropy of mixing expression \Delta S_{\mathrm{mix}}=-nR\sum x_i\ln x_i.
————————————-
Piotr: Without limitless free energy – no sane person would propose it as a cost effective way of DAC.
Nigel: Agreed. At no stage did I support or promote DAC. I didn’t think I needed to mention my position. I thought the numbers in the study spoke for themselves, showing the idea is very expensive and so doesn’t look viable. It is clearly more economic and sensible to stop the CO2 getting into the atmosphere in the first place.
However this does leave the problem that renewable energy and electrification allegedly cant solve all transport problems, so reliance is being placed on at least some limited extraction of CO2 to get to “net zero” Maybe DAC would help there but I haven’t looked at the costs / benefits and I’m sceptical.
Piotr: And if I instead plant a tree and during its life it sequesters 1 ton of CO2 in its wood – what would I need their “4.43 x 10^8J” for?
Nigel: OK, but you have the land area problem as MAR mentioned. Its very hard for me to see how we would find huge areas of land especially given a growing population. You would find some waste land too steep to farm but the numbers I’ve seen aren’t large.
Other alternatives are regenerative farming, but its very difficult keeping the carbon in the ground. And basalt rock weathering where the rock is crushed and sprinkled on the ground, but its also quite an energy intensive process. But given natural weathering is doing some of the work, surely it would use less energy overall than DAC? But the process is slow so Im not sure it would help much getting us to net zero. Its more of a tool to mop up CO2 over the longer term.
Seaweed? You would need vast volumes of sea weed. How would that work? What would that onslaught do to ocean ecosystems?
Theres certainly no easy answer to this extraction of CO2 thing.
Nigeljsays
Clarification of my response to Piotr. By ‘DAC’ I was referring to the type of carbon capture that sucks CO2 out of the air with fans. This is the way the term seems to be generally used. There are other ways of extracting carbon, that I listed.
Piotrsays
Nigel: ‘DAC’ I was referring to the type of carbon capture that sucks CO2 out of the air with fans.”
And my criticism of your source is that they behave as if they criticism of the most primitive – brute energy physical concentration of CO2 – applied to all forms of DAC. It doesn’t – so by conflating DAC with its most ineffective form – they help to throw baby with bathwater:
And those other form that I have described – both “nature-inspired” DAC which you recognized even if you seem to exaggerated their limitations, and the chemistry DAC
that you didn’t mention, are not burdened with the huge energy costs of the physical extraction of Co2 from the air.
Nigel: “This is the way the term seems to be generally used.”
I would suggest that it is the proponents of the physical extraction type of DAC that seem to be promoting their ineffective approach – as if it was the only realistic way of DAC.
Nigeljsays
Piotr,
“And my criticism of your source is that they behave as if they criticism of the most primitive – brute energy physical concentration of CO2 – applied to all forms of DAC. It doesn’t – so by conflating DAC with its most ineffective form – they help to throw baby with bathwater:”
I suppose they should have mentioned that other alternatives exist that require less human inputs of energy. All extraction of CO2 is going to use a lot of energy. but great if nature can supply some of that.
I do think the nature orientated approaches to sequestering carbon have some use and we should do what we can, The rock weathering has its positives as well. I should have mentioned that, but it was important to show the limitations. I notice you discussed their limitations in your second comment. I hadn’t actually seen that comment when I posted my first comment.
Piotr: “I am not sure about. Note the DAC in the link I gave. I would suggest that it is the proponents of the physical extraction type of DAC that seem to be promoting their ineffective approach – as if it was the only realistic way of DAC.”
The DAC people may be doing that. But Ive read quite a few articles on the issue and most people including the critics of DAC seem to use DAC in the sense of meaning extracting CO2 form the air with fans and they refer to tree planting and similar nature solutions as “carbon sequestration.” Not saying that is the logical thing because they all capture CO2 directly from the air but we are probably stuck with the convention and should go with the flow. I notice that TK made a similar comment so I don’t think it’s in my imagination.
MA Rodgersays
Nigelj,
I’m not sure that AndThenThere’sPhysics post is managing to pull the “wood” of the carbon capture problem out from in the “trees” of the physics & technology of Direct Air Capture. It certainly left me scratching my head.
The figure given for the minimum theoretical energy requirement for DAC = 0.443Gj/t(CO2) is derived (see 25-minute video in post) from the thermodynamics** with 27ºC & 400ppmCO2 and then suggests a 10% efficiency (so 4.4 Gj/t(CO2) = 16 Gj/t(C)) and gives as perhaps in reality it being 5% (8.8 Gj/t(CO2) = 32Gj/t(C)).
I’m not entirely sure what the end-game was in the illustrative scoping comparisons in the video. The idea of natural gas being used to power DAC would suggest to me a useful comparison with the energy content of natural gas w.r.t to its carbon content (63Gj/t(Carbon-content)). And the word is that today’s natural-gas-powered DAC plants burn half the carbon they extract, which may be where that 5%=32Gj/t(C) comes from.
I don’t know whether these ‘half-the-carbon’ DAC operations calcs either simply account for DAC in this capture and are ignoring the exhaust CO2 from the power-generation, or whether they are achieving this 32Gj/t(C)-efficiency when including the captured CO2 from their own power-generation, gases which should be far more concentrated CO2 & thus an easier task to capture.
(** The equation used is the ‘isothermal expansion work’ one W = R.T.In[V2/V1]. I’ll assume this is correctly applied.)
The post also attempts to give some idea of the total scale of such required DAC operations.
Myself, I have taken this graphic (which is Fig 2 from Meinshausen et al (2020) ‘The shared socio-economic pathway (SSP) greenhouse gas concentrations and their extensions to 2500’), specifically fig2c the bottom left-hand thumbnail, and estimated it was saying that in the extended SSP1-1.9 scenario (to 2500AD) it was showing negative carbon emissions through the period 2050AD-2180AD, the volume of which would roughly equal all our net-positive emissions post-2007.
And in terms of the required DAC energy spread over 130 years, so far during the period since 2007 the overwhelming majority of our primary energy use has been fossil-fuel powered, in 2024 141PWh of 168PWh = 84%.
Back in 2007. CO2 was at 384ppm which if emissions stopped would have dropped with natural draw-down by perhaps 40ppm(?) in 150 years, so leaving a CO2 concentration at roughly the 350ppm mark.
And my own mad idea for DAC. If CO2 freezes at -80ºC and the South Pole winter gets down to -60ºC, would it be worth setting up plant down there to cool some of that South Polar air that extra 20ºC and watch the CO2 rain out?
Of course, once all that CO2 can be captured, storing it away safely somewhere becomes the next challenge.
Piotrsays
MAR: “And my own mad idea for DAC. If CO2 freezes at -80ºC and the South Pole winter gets down to -60ºC, would it be worth setting up plant down there to cool some of that South Polar air that extra 20ºC and watch the CO2 rain out?”
Since getting anything to the South Pole, particularly the energy required to run it, is prohibitively expensive, in terms of $ and GHG emissions. Then there having people running machinery and maintaining it in -60C, with a windchill probably much lower than that. I have worked on a deck of the ship in -25C, and it’s not fun.
So if at all – I would suggest in Yakutia or somewhere in Siberia on there – where it gets really cold, where you have people and infrastructure and probably local source of energy – if you build it next to the natural gas fields. And I guess Russia would be interested in it –
if doable – two birds with one stone – being paid by the world for using their local gas,
and by reducing the pressure for the transition away from fossil fuels, extending the demand for their oil and gas,
I would like to comment on your idea of the hypothetical South Pole DAC plant, because it may be, in my opinion, a useful exercise.
First, we should consider that -78.5 °C is the temperature at which CO2 vapour pressure above surface of solid carbon dioxide reaches 101 325 Pa. Partial pressure of CO2 (at its present atmospheric concentration 430 ppm and at standard atmospheric pressure 101 325 Pa) is thus about 44 Pa only. To estimate CO2 sublimation point at this pressure, we can in a first approaching solve Clausius-Clapeyron equation for this compound. I asked LLM Gemini therefor (Ms. Anderson, please forgive) as follows:
“Provided that we have perfectly dry air, can you estimate a temperature of a solid surface at which carbon dioxide, having at its present concentration about 430 ppm a partial pressure about 44 Pa, would start to form frost on this surface?”
The provided result was 131 K, which is -142 °C. The engine added “for free” the following context:
Why it doesn’t snow CO₂ on Earth
Earth’s Record Low: The coldest ground temperature ever recorded on Earth is -89.2 °C (Vostok Station, Antarctica). This is still far too “warm” for CO₂ to freeze out of the air.
Mars Comparison: The atmosphere of Mars is 95% CO₂ with a partial pressure of about 600 Pa. Because the pressure is higher there (compared to Earth’s CO₂ partial pressure of 44 Pa), CO₂ frost forms at a warmer temperature, around -125 °C (148 K), which is why dry ice caps form at the Martian poles but not on Earth.
We see that on Earth, CO2 indeed fulfils the definition of a “non-condensing greenhouse gas” and that even under coldest conditions naturally occurring on Earth surface, we still would have to cool the air significantly more to freeze it out.
More detailed analysis will reveal that for an efficient CO2 removal, we need to cool the air below -150 °C, ideally to temperatures about -170 °C. With respect to energy efficiency of the separation process, this requirement may not represent a major drawback if we use heat exchangers for heat (or, rather, “cold”) recuperation.
There is, however, another aspect, common for all technical DAC processes, that is significantly more important for their technical and economic feasibility than the energy efficiency of the separation itself. It is the circumstance that the reasonable values (for both separation efficiency as well as energy efficiency) can be achieved only at slow flow rates that, at given high CO2 dilution in the ambient air and a high throughput required, unavoidably result in huge size of the necessary equipment and thus also in exorbitant investments that would have been necessary for building the respective facilities.
Let us assume a facility required for separation 1 Gt CO2 annually. The respective neat CO2 volume is 509 billion cubic meters, and this amount could be theoretically separated from some 1 180 000 cubic kilometres air. Considering that one tropical year has some 31 557 000 seconds, the necessary minimal flow rate of the ambient air through the considered facility will be about 37 393 000 m3/s. If we take 10 m/s for a reasonably achievable linear velocity of the respective air stream, the cross-section of the required “pipe” will be about 37.4 square kilometres.
Please consider that there is very questionable chance that we could “shrink” our model facility to a more reasonable size. It is because if you would like to keep the projected separation efficiency, rising linear velocity of the air stream will hardly save any volume of the necessary equipment – you may rather expect a trade-off between the necessary cross-section and the necessary length of the considered air stream. Sacrificing separation efficiency in favour of lower equipment size will hardly help as well, because this way, you will not achieve the required yield.
I am afraid that proponents of the bipartisan bill that allowed billions USD budget for building “pilot” DAC facilities in Louisiana and Texas have never showed these figures to the public (and to other representants and senators). If they did so, I cannot imagine that both chambers of the US Congress would anyway vote for the bill.
Best regards
Tomáš
Tomáš Kaliszsays
A correction to my post of 31 Dec 2025 at 7:47 PM,
The calculated 37.4 km2 cross-section of the pipeline for removing 1 Gt CO2 annually applies for linear velocity of the air stream 1 m/s. For linear velocity 10 m/s it would have been “only” 3.74 km2.
I apologize for my mistake.
P.S.
There was also an idea that as soon as electricity production in fossil fuel power plants will be replaced with cleaner sources, the existing cooling towers could serve for counter-current CO2 extraction from the ambient air, e.g. with an aqueous sodium carbonate solution (to form NaHCO3 that could be then thermally decomposed back to Na2CO3 and concentrated CO2.
This concept could perhaps work if all these power plants will be refurbished as nuclear, because cooling towers need the waste heat for keeping them running. In this scenario, roughly estimated capacity of all existing cooling towers worldwide might enable DAC withdrawal of some 0.4-0-8 Gt CO2/year.
John Pollacksays
Tomáš, you have amply demonstrated that DAC of CO2 by freezing is completely impractical, even at Antarctic temperatures.. One factor you omitted (although it was not necessary for your conclusion) is that the coldest Antarctic temperatures occur at high elevations in the interior, where the ambient air pressure is probably 75 or 80 kPa, rather than around 101 kPa.
Susan Andersonsays
Nigelj: thanks for reminding us of aTTP’s useful evaluation. Putting hypothetical numbers to impossible dreams is yet another way to remind us that we need to deal with the disease, not the symptoms, of global warming/climate change and other forms of toxic waste and excessive exploitation of resources on a finite planet.
We are so to our comforts and entertainments (honestly, sports and spectacle are out of control and getting worse, and crypto and AI excesses – wealth and power taking more and giving less). The idea of fitting our needs to reality is so unpalatable we dream that we can ‘fix’ the problem with some unknown technology in some ideal future. What we know is what we should heed. We need a great deal less stuff, and we certainly need to stop the lies, bullying, and looting. Must … stop … now.
Piotrsays
And here is the comment I have left under the video the blog was referring to. The youtube video is 2 years old, so the correction there is, as they say closing the barn doors after the horses have been long sold for horse meat to Japan….
======
Fancy graphics, ominous music and the painfully slow delivery won’t change the fact that you are presenting a strawman – NO feasible DAC technology is based on the physical concentration of atm. CO2 to which your thermodynamics argument refers to – PRECISELY because the thermodynamics limitations of physical concentrations people have known for a long time.
The feasible DAC solutions do NOT need physical concentration of CO2 and fall into two categories:
– amplifying the natural process of CO2 uptake like plant and algal growth. or weathering of carbonate and silicate rocks, both of which get their CO2 from ambient air by diffusion,
-or a scaled up chemical reaction where the components of the “brew” take up CO2 chemically – again NOT REQUIRING physical concentration of CO2.
Sure, both still face the far from trivial problems of scaling up enough, ecological problems (say ocean fertilization), but those have to do with space, technology, and energy needed to run these systems, NOT the stupendous thermodynamic cost of the concentration process they DON’T USE.
Thank you for your points, I fully agree that any technical means for carbon dioxide removal (CDR*) from Earth atmosphere can hardly ever become technically and economically feasible.
I would like to add only that in my recent post submitted on 31 Dec 2025 at 7:47 PM,
I tried to show that the theoretical thermodynamic value of the respective mixing Gibbs energy may be of secondary importance for technical and economic feasibility of ANY practically applicable process for extracting a minority component from a very diluted solution thereof.
It is because this value can be reached only at negligible process throughputs or in facilities of an impossible size (and price). What matters more are thus (i) unavoidable trade-offs between real energy consumption in a facility designed for a required throughput on one hand and investments necessary for commissioning this facility on the other hand, and (ii) the circumstance that at high dilution of the separated component, a big (and commensurately expensive) equipment is anyway necessary for the required reasonable throughput.
I would like to thank you also for all other helpful exchanges with me and wish you all the best in the next year. As I equally appreciate all honest commenters and cannot individually approach everyone, please let me hereby send my thanks and greetings also to them, as well as to the moderators for keeping their website running.
Tomáš
*P.S.
I thought that the term “direct air capture” (DAC) is used just for the CDR methods exploiting a separation step that relies on technical means. If so, I would perhaps rather desist from using the term DAC for such CDR methods like tree planting, wherein the separation step exploits only natural processes and “means”.
Hmm,
Not to be picky, but you link to a year-old report.
The report describes the power-project for a DAC scheme which itself plans to capture 500,000 tons(CO2) per year of the annual 40,000,000,000 tons(CO2) of global emissions. This 415MW scheme might provide a rough estimate of the energy requirement for DAC, quoted as saving 250,000 ton(CO2) presumably by being solar generation and then doubling this with the DAC (although there will maybe be FF-generated electric power that could have been avoided as an alternative). Worryingly, when I run a check on that claim, I don’t seem to get that level of emissions saving from the solar (22kt(CO2) for gas-powered, 40kt(CO2) for coal-powered) but that may be an untamed decimal point!
A 2023 Guardian article ridiculed the idea that an oil company is quoted using this to excuse for the continuing existence of fossil-fuel use, a project which reverses “about 260 seconds of the world’s (annual) emissions.” And it will be up-&-running in 2025? Apparently no sign of that yet.
The storage scheme is described as having 3,000,000,000 ton(CO2) capacity (so able to store far more than this one DAC plant) but details are seriously vague given a quoted 2025 (though slipped) start-date. The one bit of happy talk is the mention of this storage being a “saline aquifer” and not the usual old oil wells that need gas injection to boost output.
Datasays
MA Rodger says – This 415MW scheme
1 Jan 2026 at 1:31 PM
Data (or whatever you call yourself),
Thank you. That helps a little. But reducing the ‘nameplate’ power rating by three won’t entirely compensate for the calculated power output being ten-times too low. I did note that the quoted “CO2 emissions avoided” was given as “250K MT” which doesn’t seem to make much sense either as an annual value or a life-time value. Would you have gleaned some words of wisdom on that mystery?
I think that investing money collected for carbon credits into any form of DAC is basically equal to burning them.
For Occidental, the value is clearly in the created PR, namely in raising false public belief that continuing in their fossil fuel business is justified by, in parallel, removing (in fact, a negligible fraction of) the CO2 released by this business back from the atmosphere. If the enterprise is, moreover, financed by others, it is an excellent business deal for them. Unfortunately, an exact opposite for the rest of the world, I am afraid.
My personal opinion on such “decarbonization achievements”: Shame on all who contributed to shaping “climate policies” the way that enabled this scam – not only on the politicians who approved the rules, but also on all scientists and journalists promoting DAC as a possible alternative to reduction of fossil fuel consumption and thus confusing the public.
Best regards
Tomáš
Datasays
Don’t worry, someone funded something.
Antarctica
↔
Seaweed
↔
Basalt
↔
$415M solar DAC plant
Different scenery.
Same refusal.
So yes — laugh.
That’s comedy. Dark comedy, but comedy nonetheless.
Datasays
I checked ATTP’s discussion. Mostly circular.
Most discussions around DAC, net zero, and carbon budgets sound like a lot of technical back-and-forth, but beneath the noise there’s a deeper structural problem that few acknowledge. The core failure everyone is skating around is this: climate mitigation treats a living, historical, relational Earth as if it were a controllable machine — and mistakes abstractions for reality.
DAC is not the villain. Net zero is not the villain. Carbon budgets are not the villain. They are symptoms of a deeper refusal: to accept irreversibility, to accept inheritance, to accept that the scale and power of civilization itself are the problem. That’s why techno-fixes proliferate, limits are endlessly deferred, and language becomes euphemistic and circular.
All the debate about energy requirements, efficiencies, or LULUCF ratios is still operating inside the machine metaphor: inputs, outputs, efficiencies, substitutions. As Whitehead would say, they are mistaking abstractions for concrete reality. To put it sharply: you cannot budget the future of a system whose governing dynamics change as a function of its past. That is the dagger cutting through all these circular debates.
Datasays
Too often the conversation is dominated by endless ‘we-need’ imaginings — hypothetical fixes projected onto everyone, as if collective virtue alone could override physical and historical constraints.
Datasays
I was reviewing some past science explanations here, while wondering where we are now. One item stands out: did any of this really clear anything up yet about the so‑called warming spike and sudden acceleration?
Looking back at the 2023–24 GMST spike, it’s clear the anomaly exists, is physically meaningful, and remains only partially explained. Yet the community narrative has largely minimized it — framing it as “within expected variability” using wide uncertainty envelopes and probabilistic language, and emphasizing long-term trends rather than the unusual short-term jump.
Hansen’s physics-driven perspective, highlighting over-ocean EEI, aerosols, and cloud feedbacks, remains plausible but largely absent from synthesis papers. Acceleration in surface temperatures is understated; new records are noted, but the discussion rarely emphasizes how rapid or exceptional the spike was.
In short, the 2023–24 anomaly is still there, but its significance has largely been buried in narrative framing, leaving the gap between the data and the discussion surprisingly wide. My instinct is that we’ll have to wait another year or two before we get a true “England + Cowtan & Way moment” for this spike.
Hiatus context — Matthew England (Australia):
The “hiatus” in global surface warming (~1998–2012) puzzled the community because surface temperatures seemed to stall while greenhouse gases continued rising. England and colleagues proposed the tropical Pacific / ocean heat uptake mechanism — specifically, enhanced La Niña–like conditions drove more heat into the deep ocean, temporarily masking surface warming.
Key paper:
England, M.H., McGregor, S., Spence, P. et al. (2014) “Recent intensification of wind-driven circulation in the Pacific and the ongoing warming hiatus.” Nature Climate Change, 4, 222–227.
Extract: “Enhanced trade winds in the tropical Pacific drive more heat into the deep ocean, explaining the slowdown in surface warming.”
This work largely predated or overlapped with Cowtan & Way’s 2014–2015 paper on temperature coverage bias, which corrected gaps in Arctic/remote data and partially “recovered” surface warming during the hiatus.
This work largely predated or overlapped with Cowtan & Way (2014–2015), which corrected gaps in Arctic/remote data and partially “recovered” surface warming during the hiatus. Together, these contributions resolved the hiatus puzzle.
Maybe one day the 2023–24 warming anomalies will be equally explained, using real data and a dose of common sense.
Nigeljsays
Data: “Looking back at the 2023–24 GMST spike, it’s clear the anomaly exists, is physically meaningful, and remains only partially explained. Yet the community narrative has largely minimized it — framing it as “within expected variability” using wide uncertainty envelopes and probabilistic language, and emphasizing long-term trends rather than the unusual short-term jump.”
“Hansen’s physics-driven perspective, highlighting over-ocean EEI, aerosols, and cloud feedbacks, remains plausible but largely absent from synthesis papers. Acceleration in surface temperatures is understated; new records are noted, but the discussion rarely emphasizes how rapid or exceptional the spike was.”
The warming spike in 2024 specifically has been well explained by a combination of AGW, el nino, aerosols reductions (using mainstream estimate of aerosol forcing number, not Hansens high number), and the solar cycle and this website did an analysis on that and I posted a study by Carbon Brief on it written by Zeke Hausfather here:
The unusually intense warming in 2023 has not been as well explained. Even when accounting for AGW aerosols and el nino and the solar cycle, its still not fully explained. as Zeke mentions. It has indeed been framed as within the bounds of natural variability which isn’t a full explanation.
Hansens explanation for both 2023 and 2024 unusual warming is that aerosol reductions are a huge factor, starting around 10 years ago in China, and shipping aerosol reductions around 2020, where the energy was sequestered in the oceans and came out over that period 2023 – 2024 el nino. given el ninos release heat. He claims aerosols have a larger forcing effect than the mainstream science.
It is quite convincing except when you apply it to 2023, because the unusual levels of heating were evident before this year truly morphed into an el nino so why would the heat be expelled at that stage? And if his very high estimation of aerosols would still somehow explain 2023 temperatures, then 2024 should be warmer than it was assuming Hausthfathers analysis is correct on things like the solarcycle. So 2023 is still a mystery. But IMO Hansen is putting very useful ideas on the table for consideration. He leads the way.
December 2025 saw global temperature anomalies dropping down quite sharply after the warm wobble of Sept-Nov. ClimatePulse has but one day yet undeclared and the Dec-to-date anomaly is sitting at +0.48ºC. (Sept-to-Nov averaged +0.67ºC while Jun-Aug averaged +0.47ºC, these all down on the start of the year with Jan 2025 +0.79ºC.)
The warmth of Sept & Oct was due to the SH with a lot of that down to an abnormally warm Antarctic. Down there you regularly see wobbles of +/- 3ºC but wobbles usually not lasting anything like two months. With the Antarctic comprising 10% of the SH, such a long Antarctic wobbles did impact the SH Sept/Oct anomalies and also the global anomalies for Sept & Oct. The Sept-Oct wobble was enough to give a record annual Antarctic anomaly of +1.2ºC which is +0.6ºC above recent years. (So that Antarctic wobble was enough to add an unexpected +0.025ºC to the global 2025 average.)
The warm anomaly of Nov was a NH thing and not unexpected. In the NH, Autumn warming has been more pronounced than that of the other seasons and the resulting anomaly wobble is often quite a feature, although less-so in La Niña years. So far, this 2025 NH wobble seems quite short-lived, even with the developing La Niña.
With the anomaly of +0.48ºC, December 2025 becomes the 5th warmest December on the ERA5 record, below 2023 (+0.84ºC), 2024 (+0.76ºC) and below =3rd 2019 & 2015 (+0.54ºC), both the latter boosted by El Niño, with 2025 sitting ahead of 6th-place 2017 (+0.37ºC), 2016 (+0.34ºC) & 2018 (+0.33ºC).
Note there has been a bit of underlying AGW since 2018 and Dec 2016, 2017 & 2018 all sat above the 2010-22 linear regression line. December 2025 sits below that projected 2010-22 warming rate and is the 4th 2025 month (along with Jun, Jul & Aug) in ERA5 sitting below that rate. Previously, the most recent was back in May 2023.
Without the rather pronounced Sept-Nov warm wobble, the 2023-24 “bananas!!” temperatures could be surely declared dead and buried. And even so, I can’t see it as resulting from any reduction in aerosol pollution which is a NH effect (making it very unlikely) and permanent (making it surely impossible).
The annual ERA5 anomaly thus comes in at +0.59ºC, this only a shade below the 2023 average (+0.60ºC) but well below 2024 (+0.72ºC).
(In ‘above pre-industrial’, that’s 2024 = +1.60ºC, 2023 = +1.48ºC, 2025 = +1.47ºC.)
With the early months of 2025 still running with “bananas!!” anomalies, the 2025 annual anomaly sits above the 4th warmest year (2016 +0.44ºC), 5th (2020 +0.43ºC) & 6th 2019 (2019 +0.34ºC).
In ‘above pre-industrial’, that’s 2024 = +1.60ºC, 2023 = +1.48ºC, 2025 = +1.47ºC.
[just taking these at face value, unconfirmed]
Let’s be clear: the 2023–24 GMST spike — the so-called “Bananas!!” anomaly — is real and physically meaningful.
No cherry-picked NH aerosol adjustment, no local wobble, no post-hoc statistical contortion can erase it. It survives scrutiny across ERA5, satellite datasets, and multi-model comparisons. Attempting to attribute it solely to a short-lived NH aerosol reduction is inconsistent with physics and observations: the effect would be regional, transient, and far smaller than the global anomaly we saw.
Hansen’s acid test remains valid: the abrupt magnitude, persistence, and hemispheric spread of the spike confirm something unusual happened — energy was redistributed, feedbacks amplified, and surface temperatures jumped well above expectations. Your data — whether looking at Antarctic wobbles, seasonal NH/SH offsets, or annual averages — only confirms this.
In short: the “Bananas!!” temperatures are not an artifact, they are not explainable by simplistic aerosol arguments, and they are not “dead and buried.” They happened. They are real. Deal with it.
MA Rodgersays
Data (or whatever you call yourself),
The problem with this particular word salad you serve up here is that the ‘Hansen’ position you argue to support is contradicted by the absence of on-going “bananas!!” today, these both being positions you argue to support.
That is the ‘Hansen’ acid test was to show that the “bananas!!” were caused by reduction in aerosols or in feedbacks, this the ‘Hansen’ position. with both aerosols or feedbacks pointing to a high ECS. This ‘Hansen’ position is the opposite of the other position you argue for here. That is ‘Hansen’ is not supported by failure of his acid test where the “bananas!!” that once “happened” today are gone.
Perhaps you could tell that to your AI bot and it can then do better arranging its answer-ducks in a proper row.
Datasays
Allow me to summarize and hopefully put this to bed once and for all.
Atomsk’s Sanakan claims: the observed warming trend, better observationally-constrained CMIP6 models, CMIP5 models, the IPCC, etc., show we’re on pace for ~2°C by 2045-2050, 3°C by 2075-2090 (2060 at the earliest), and ~3.5°C by the end of the century.
Simultaneously, he claims: the German Physical Society (DPG) and the German Meteorological Society (DMG) are cherry-picking a small number of CMIP6 models known to overestimate warming, including up to 2025 — and if those models are too warm in 2025, they will also be too warm for 2050.
Across two months of fragmented threads, Atomsk offers a mix of non-peer-reviewed “references” — Forster 2025, Copernicus, Carbon Brief, ERA5 — presented as if they were confirmed projections. I have checked each source individually; none definitively supports the precise numbers he asserts. These references provide plausible ranges or scenario envelopes, not point predictions.
By combining multiple assumptions and datasets into a single narrative, Atomsk creates the impression of certainty where none exists. This rhetorical strategy — confident language, volume, and selective references — conceals the underlying uncertainty. Readers should treat such aggregated claims as illustrative, not authoritative, and distinguish between scenario envelopes and validated projections.
Nigeljsays
AS also provided a link to the warming projections in the last IPCC report, and even the worst case RCP8.5 scenario didn’t get to 3 degrees by 2050. So is the IPCC report crap as well?
Yup, Nigelj. The sockpuppet moved their response down here to make it harder to see the posts where I did that. Here I cited this from IPCC 2021 figure SPM.8. They also don’t understand the difference between projections vs. predictions.
And they’re willfully disinforming. For example, they said “Atomsk offers a mix of non-peer-reviewed “references” — Forster 2025, Copernicus, Carbon Brief, ERA5“. But that’s a lie since Forster 2025 was peer-reviewed. There’s even a tab at the paper’s link naming peer reviewers, showing their reviews, etc. The sockpuppet also left out other peer-reviewed sources they were cited, such as IPCC reports, Xu 2018, Dai 2023, and Hansen 2023. They tried to hide that from people by moving their response down here and not linking to what they’re responding to. Good illustration of how these Data/Jim/Neurodivergent/Mo Yunus/… sockpuppet accounts try to deceive people. How they respond (or don’t respond) to being caught on this obvious disinformation should further reveal their character.
I call RC readers’ attention to Zeke Hausfather’s blog post last week: https://www.theclimatebrink.com/p/consensus-machines. He offers a brief but helpful tutorial on how generative AIs arrive at their results, But first he says:
Zeke: there is a case to be made that the transition toward using LLMs as sources of knowledge might end up inadvertently recentering scientific expertise and creating a more unified information landscape for society.
If his explanation is accurate, I can see how that might work. But you should argue with him, not me, as my ignorance of the technology is still encyclopedic.
Two categorical aspects to current A.I. — (1) the use of LLMs to pattern match how humans convey (writing, visuals) or process information (software development) and (2) the use of NNs and related tools to train on data as a way to make predictions or solve problems.
The latter can be used in climate science, but it’s not clear what breakthrough it will discover. And if it does discover something, reverse engineering it will still be a pain. Yet, there is still work to be done hammering away via human ingenuity, such as this for modeling fluid dynamics => https://geoenergymath.com/2025/12/02/hidden-latent-manifolds-in-fluid-dynamics/
I also missed he paper in the link below when it first came out, but in it Pierrehumbert describes how and why climate scientists were awarded the Nobel Prize in Physics:
Fluid Mechanics: the quintessential complex system
How things can change in a few years.
Thanks for the Pierrehumbert reference… should be required reading before commenting here.
The ERA5 global SAT anomaly for November averages out at +0.65°C, down on October’s +0.70°C and a sliver below September’s +0.66°C.
The last three months sit above the summer months which averaged +0.47°C.
But November was different from Sept/Oct. The ERA5 numbers at the Uni of Main’s Climate Re-analyser site show November was warmer due to a warm northern hemisphere, (this due to the now-normal warmer NH Autumns that result from AGW. This NH Autumn wobble is usually smaller during La Niñas and the ENSO watchers are showing we have weak La Niña conditions.)
Unlike November, in Sept/Oct the higher SAT anomalies were due to a warmer southern hemisphere and in particular due to unusual Antarctic temperatures which experienced a big warm wobble.
A more reliable (less wobbly) measure of global temperature, the ERA5 60N-60S SST anomaly dropped to an average of +0.29°C for November, this now down below (just) levels projected prior to the “bananas!!” temperatures of 2023/24, the first time since Feb 2023.
(See graphics various at the Banana!! Watch page.)
Tropical “super greenhouse effect” not so super?
Ok, since I can not post a chart here, let me give you the data. Left column are the surface temperatures in the tropics (30°N-30°S) as taken from Ramanathan 2005. In the right column are the average lower troposphere temperatures also within the tropics (30°N-30°S) from the UAH data set.
Ts / Tlt
298.64 272.05
298.82 272.18
299.30 272.31
299.47 272.46
299.36 272.52
298.92 272.42
298.62 272.19
298.57 272.23
298.76 272.27
298.78 272.23
298.56 272.12
298.30 272.08
Max – Min equals 1.17K for Ts and 0.47K for Tlt. The variation of Tlt thus is 60% smaller than that of Ts. Ramanathan argued there was a very strong greenhouse effect in the tropics, and even “super GHE” in the inner tropics. That is because tropical dOLR/dTs is almost zero and partially below zero in the inner tropics. As the surface warms in the annual cycle, there is barely an increase in outgoing longwave radiation, ie the system can not cool itself.
The implicit assumption is that the increase in WV with warming would almost perfectly negate the otherwise to be expected Planck Response. So if you assume a tropical Planck Respone of say 3.5W/m2, while you observe dOLR/dTs ≈ 0, that would indicate the presence of a total of 3.5W/m2 positive feedbacks. Depending on whether you sample for skies only or not, that could also include a cloud feedback component. And most notably, the lapse rate feedback component is assumed to be negative.
WVF + CF + LRF = 3.5
For example you could solve this restriction then like WVF = 4, CF = 0.5, LRF = -1. A strong positive WVF and some neg. LRF. By sampling for clear skies one can try to eliminate the CF variable.
Anyway, the problem is documented in the data above. With Tlt being so sluggish relative to Ts, there is no negative LRF component, but instead it must be a huge positive LRF compoent, like 2.1W/m2, if we assume Tlt as a proxy for Tz. Of course there is no actual positive “lapse rate feedback” in this instance, it is just, let us call it, tropospheric temperature autonomy.
It then follows there is just a small WVF (+CF) residual of only 1.4W/m2. That is a very moderate WVF (+CF), easily to be dominated by a much larger negativ LRF with long term warming. And of course that is no “super GHE”..
I’ve not time to study E. Schaffer comment but anybody who has I suggest you look at what must be about 27 million clear-sky “greenhouse effect (GHE)” measurements for 1998-2014 for 63,000 equal area locations around Earth (grid pixels) at 2:27 at https://www.youtube.com/watch?v=NNgMyDRWWrA This of course is because LWIR-active GHG molecules “absorb” & “manufacture” photons and do not “absorb photons and re-emit 50% back down again”, especially not “to the surface”.
Then there’s fluid dynamics, an entirely-different and vastly-important aspect of Earth’s climate with it’s 2 big fluids “water” and “air”, about which I know bits and bobs but not much. I know they shift energy around Earth at like ~6,000 terawatts and from ocean to land at like ~2,200 terawatts.
Barry E Finch,
Myself, I would hope nobody wastes their time with the E. Schaffer comment above. There’s a lot of strange stuff that doesn’t add up and if you visit the weblink provided by E. Schaffer to find some clarity, you arrive at what he styles “The Greenhouse Defect – Saving the planet …from idiocy – The most disruptive site on climate science.”
An exemplar of the strange stuff in his comment is the insistence that “you observe dOLR/dTs ≈ 0” when, he suggests, the expectation would be something of the order of 3.5Wm^-2/deg C. CERES data shows a healthy annual OLR cycle averaging 3.4Wm^-2 peak-to-peak, not a double-peaked cycle as seen in Tropical SAT but big enough to show dOLR/dTs ≠ 0.
Ramanathan 2005 (book, not article)
http://ruby.fgcu.edu/courses/twimberley/envirophilo/Forcing.pdf
Check page 139 for the “double-peaked cycle” in the tropics.
E. Schaffer,
The difficulty with your reference to “Ramanathan 2005” was because it isn’t a book but a chapter in a book, specifically Kiehl & Ramanathan (2006) ‘Frontiers of Climate Modeling’. However I did find the link provided within your website.
Perhaps I should also point out that I noticed your problematic paywalled reference Raval & Ramanathan (1989) ‘Observational Determination of the Greenhouse Effect’ which is actually available for skinflints and paupers and all, being presented within Manowitz (1990) ‘Gobal Climate Feedbacks’ – Proceedings of the Brookhaven National Laboratory Workshop – June 3rd-6th, 1990.
Your confused presentation does not entice me into trying to understand properly what you are about but I would suggest your seeming mission to find fundamental flaws in the science supporting AGW by identifying some “unthinkable … blunder (that) went unnoticed for decades”: this mission is likely a fools errand.
Concerning specifically the tropical “super GHE” which you seem to want to paint as some figment of errant modelling, a quick look at the CERES data (Clear sky OLR 30N-30S) alongside ERA5 SAT (30N-30S) might just give a measure of your “WVF + LRF” w.r.t. SAT. With that thought in mind, see the graphic here – POSTED 6th December 2025.
MAR, actually the dOLR/dTs < 0 is a reality, as a best-fit trend, from CERES analysis. It's at https://www.youtube.com/watch?v=NNgMyDRWWrA at 2:27 with surface temperature increasing from ~299.5K to ~302.2K the OLR goes down from ~289 w/m**2 to 286 w/m**2, an apparent Super GHE, then rapidly returning, to the linear trend from ~302.2K to ~302.7K. However, it's a best-fit trend from a huge hash of measurements with wide range and seems likely to me that it's to do with some regional variability thing so, sort of, if there's 299.5K in some specific place and 302.2K in some other specific place then for these specific places there's clear-sky OLR of 289 w/m**2 at that specific 299.5K place and of 286 w/m**2 at that specific 302.2K place.
I greatly doubt that the trend through the vast hash plot means that when that 299.5K place warms to 302.2K its OLR goes down. I think its OLR goes up and what's being shown is comparing differing regions with something different between them that causes them not to respond identically. Tropical ocean SST typical is in that range but I don't know the relevance.
One needs to be careful about what perspective is in play. In this video, as far as I have seen it, they exclusive talk about the regional proxy. It is no secret this proxy does not work and is obsolete. Let me quote Dessler et al 2008:
“This is a quantitative estimate of the effect of the changing lapse rate on dOLR/dTs, and it shows that it is negative for almost all values of Ts. In other words, as Ts increases, so does the lapse rate, and the general effect of this is to reduce dOLR/dTs, and therefore OLR, below what they would be if the atmosphere maintained a constant lapse rate.
In most climate-change scenarios, the upper troposphere is expected to warm more than the surface, and the additional radiation from a warmer upper troposphere will act as a negative feedback on the warming.
This result demonstrates the unsuitability of using variations in different regions in our present climate as a proxy for climate change.”
The reason why there is such a reversal of the trend is with the inner tropics. There you have strong convective clouds, optically thick, reaching up to high altitudes and low temperatures. This of course reduces OLR.
Ramanathan however deals with the seasonal proxy and derives the “super GHE” from that perspective.
E. Schaffer says 8 Dec 2025 (with no “Reply” button on my screen, some weird hosting site thing I suppose) “The reason why there is such a reversal of the trend is with the inner tropics. There you have strong convective clouds, optically thick, reaching up to high altitudes and low temperatures. This of course reduces OLR. The CERES plot that I referenced is stated as being measurements for cloud-free skies only.
@BEF My bad, should have looked closer. I still had Fig.1 from Dessler et al 2008 on my mind, which is clear sky data btw.
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2008JD010137
Then thinking about it, it is somewhat odd. Is says “nighttime, clear-sky measurements of OLR” – I mean where are nightime temperatures reaching 310K and more?! Maybe right after sunset, idk. Anyway..
If it is a straight line with nightime temperatures, but features are “bulge” during day time (or all time), that would suggest it is mainly due to the size of the atmospheric window. From previous analyses I tend to believe the clear sky window is about twice (if not more) the size in the outer- and in the inner tropics.
With otherwise identical Ts it might mean a difference of 40-50W/m2 in the share of surface emissions in OLR. OLR itself will then be way more sensitive day time heat in the outer tropics. Would explain why it is straight line for nighttime OLR..
BEF: LWIR-active GHG molecules “absorb” & “manufacture” photons and do not “absorb photons and re-emit 50% back down again”, especially not “to the surface”.
BPL: Not sure what you’re saying here. There is definitely atmospheric back-radiation; we can measure it with instruments.
BPL, he’s trying to be precise about the language.
Photons are converted to energy within the molecule; the energy may be re-emitted or transferred to other molecules through physical interaction. (I believe the latter is the primary mechanism.)
And if the energy is re-emitted downward as a “new photon”, that photon isn’t likely to make it to the surface before being absorbed.
Zebra yep, not at all just a matter of phrasing as bods kept telling me on various Social Media (because everybody assigns their time and interests and they got involved without being interested). There’s an obvious fundamental difference regarding a popular type of Fossil memes, some variants of them, the last couple decades. Isn’t there? As I first posted on RC UV as a Trial Balloon years back to judge interest but was censored, then tried again 6 months later with something obtuse to check the censorship. You & MAR exchanged briefly and MAR noted that I’m crazy, which of course is correct but not relevant to radiative physics, which couldn’t care less about humans.
Barton. I’m not sure why you’re not sure. Looks crystal clear to me and it’s correct in overall essence per orbiting measurement since 1964 IRIS-A on Nimbus 1.
“atmospheric back-radiation; we can measure it with instruments”. Yep the down-welling radiation is measured at land surfaces and I think on Research Vessels. Please indicate how the pyrgeometers identify that these photons entering the sensor were absorbed from below by H2O gas, CO2, CH4, O3, N2O, CFCs molecules (the GHGMs) and then re-emitted back down again as you strongly claim, rather than being photons that were manufactured by the GHGMs as I strongly claim since July 2018 and you strongly refute (Me: when GHGMs collide they sometimes, not often, vibrate, maybe rotate I’ll call it all “oscillate”, as a result and then they sometimes, not often, emit a photon as a result of oscillating. BPL: Nope, they can’t do that, GHGMs are third-rate, defective molecules). On terminology I greatly prefer “down-welling radiation”, because its clear because all understand what “down” means, to “back-radiation” which is meaningless.
Certain molecules and atoms in solids, liquids and gases at certain temperatures are manufacturing photons all the way from the centre of Earth’s core to the top of Earth’s atmosphere. Right? This manufacture doesn’t stop at what we call “the surface”, does it?, it tapers off as gas concentration increases with altitude.
If the ocean somewhere geographically is divided into 27,500,000 layers each 200 microns thick then the H2O molecules in each layer are manufacturing photons and when not manufacturing photons they are either oscillating because they absorbed a photon or doing no manufacturing or absorbing, just “jiggling” with the energy that doesn’t involve photons. Each layer 200 microns thick emits ~460 w/m**2 of photons from its upper and its lower surface when it’s at 27 degrees, ~390 w/m**2 from its upper and its lower surface when it’s at 15 degrees and ~315 w/m**2 of photons from its upper and its lower surface when it’s at 0 degrees. Obviously, the molecules in each layer absorb photons entering from above and below and absorb some portion of their own photons. The ~315 w/m**2 of photons manufactured in the lowest layer 200 microns thick goes from its lower surface into the sea bed and the ~390 w/m**2 of photons (varying ~305 w/m**2 to ~460 w/m**2) manufactured in the highest layer 200 microns thick goes from its upper surface into the atmosphere.
The molecules and atoms from Earth’s core to its surface must be doing the same as the ocean, with the photon fluxes being much vaster.
The N2, O2, Ar molecules don’t manufacture non-negligible amounts but the GHGMs manufacture large photon quantities but not like the solids and liquids quantities because gas density is far lower. Take radiation of 4.5 – 100 microns wavelength except exclude 8.0-9.0 & 10.0-13.0 microns. Suppose the GHGMs in the lowest 200 m of atmosphere absorb all photons going in from above and below. The GHGMs in such a tall layer will also absorb most of the photons they manufacture but there will be leakage from its upper and its lower surface, which are 200 m apart. The leakage from its lower surface is what you (and presumably physicists) are calling “back-radiation” for no meaningful reason because that radiation isn’t going back anywhere. I call it “down-welling radiation” (except when the Gang Du Jour is using “back-radiation” and I don’t want to detract with wordiness from whatever the main point, such as “it’s 0.04%!!” or whatever).
The leakage from its upper surface enters the 200 m of atmosphere above. And so on. Obviously, this is simplified and physicists calculating quantities must determine the photon fluxes up & down from each layer (I know that William & Will Happer used 100 m layers, I don’t know whether that’s typical) and include the portion that can go through the layer. Obviously, the layers would need to get increasingly tall with altitude if one wanted to guarantee that each layer was 100% opaque to photons passing entirely through it, but I’m inferring that physicists don’t do it that way. I’m rather sure that that’s the correct physics as close as matters though and I’m not sure what you’re not sure about with that simple-enough thing. If there are 2 suitably-sized parcels of matter with a common boundary they exchange radiation with the warmer radiating more into the cooler than the cooler radiates into the warmer. Applies to solids, liquids and GHGMs.
On some Social Media places like GoogleysTubes I’d sometimes offer anybody interested to ask me why that isn’t just semantics and then I’d be willing to consume time (for no income) explaining why but I never found interest, just some stupid, ignorant replies such as “@mrunning10 Reported again. Because you’re insane” from the Trolls who are probably the grandsons of the Trolls around here. That’s Life.
Barry E Finch says
On some Social Media places like GoogleysTubes I’d sometimes offer anybody interested to ask me why that isn’t just semantics and then I’d be willing to consume time (for no income) explaining why but I never found interest, just some stupid, ignorant replies such as “@mrunning10 Reported again. Because you’re insane” from the Trolls who are probably the grandsons of the Trolls around here. That’s Life.
Neurodivergent responds; nah couldn’t be you who’s the mad hatter incoherent mad troll. nah, never. It’s everyone else who oppressing’ ya freedumbs dude.
jeez get lost, seriously. or get some therapy.
BEF: On terminology I greatly prefer “down-welling radiation”, because its clear because all understand what “down” means, to “back-radiation” which is meaningless.
BPL: It’s the accepted term. Like “greenhouse effect,” it may not be strictly accurate, but it’s too late to change the usage.
(cont. from https://www.realclimate.org/index.php/archives/2025/11/unforced-variations-nov-2025/#comment-842186 …)
POV = point of view
LOS = line of sight
mass absorption coefficient k_a for the air
= absorption cross-sectional area per unit mass of air [m²/kg]
= Σ_i ( n_i · σ_{a,i} ) ÷ ρ_{air} )
At any given POV, there is some (spectral) radiance ((spectral) brightness) L_ν you see coming from the direction (θ,ϕ); move backward a tiny (infinitesimal/differential) distance ds along the LOS to put additional material in front of you, with optical thickness dτ; because of the tiny amount of this added τ, we can proceed assuming none of its absorption cross sections σ_a overlap. Thus, the fraction of L_ν (seen looking from POV) which is blocked and replaced by the glow B_ ν of that added dτ is that dτ. Ie. The change in L_ν over ds is:
dL_ν = ( B_ ν − L_ν ) · dτ
ie. L_ν + dL_ν = L_ν · ( 1 − dτ ) + B_ ν · dτ
PS: PPIA:
ds = | sec(θ) dz | = | dz / cos(θ) |
dτ = | dτ_{vc} / cos(θ) |
= k_a · ρ_{air} · ds
= Σ_i ( n_i · σ_{a,i} ) · ds
= μ_a · ds = β_a · ds
( see https://en.wikipedia.org/wiki/Schwarzschild%27s_equation_for_radiative_transfer – note they are using “spectral intensity” to refer to spectral radiance. **)
Then integrate over s or τ or z or mp ( |d(mp)|= | ρ_{air} · dz | )…
Exact analytic solutions can be found for some cases eg.
where τ is measured along LOS, in the direction the light is going (you’re looking toward smaller τ in this context), from a point where L_ν = L_{ν,0} & B_ν = B_{ν,0} .
Constant B_ν :
L_ν = B_ν + ( L_{ν,0} − B_{ν,0} ) · exp(−τ)
asymptote: radiance lags behind by 1 unit of τ , ie.
L_{ν,asymp} = B_ν
Linear B_ν = B_{ν,0} + a·τ :
L_ν = B_ν ( τ ) – a + ( L_{ν,0} − B_{ν,0} ) · exp(−τ)
asymptote: radiance lags behind by 1 unit of τ , ie.
L_{ν,asymp} = B_ν ( τ − 1 ) = B_ν ( τ ) – a
More generally, the solution is an asymptote L_{ν,asymp} ( τ ) for a particular function of B_ν ( τ ), plus an exponentially decaying term that is
L_ν − L_{ν,asymp}
at any given τ
(which may be nonzero because that particular function of B_ν ( τ ) may only apply over a limited domain of τ; the decaying perturbation is coming from the L_ν entering that domain).
See https://scienceopinionsfunandotherthings.wordpress.com/2025/12/09/for-asymptotic-radiances-ppia-linear-and-general-cases-wip-awaiting-final-proofread-double-check-diagrams-pending/
(Just posted that; had been sitting on it for awhile; hope to post related posts soon, with formulas of L_ν and flux density Fd_ν for sinusoidal B_ν ( τ ))
** https://www.realclimate.org/index.php/archives/2024/08/unforced-variations-aug-2024/#comment-823976n : (edited from original)
https://en.wikipedia.org/wiki/Radiance#SI_radiometry_units :
Φ (radiant) flux: rate of energy flow, ie. power: [J/s = W]
flux density: flux per unit area (through an area): [W/m²]
I intensity: flux per unit solid angle, in a direction: [W/sr], eg. through an area of some orientation
(note the word “intensity” is often used for other things, though)
L radiance: flux density per unit solid angle, in a direction, through an area facing that direction: [W/(m²·sr)] If you focus at ∞ (infinite distance), then, with some caveats***, radiance corresponds to the brightness you see at a point in your visual field.
spectral ___ ≡ amount of ___ per unit of the spectrum (at a given point in the spectrum).
Eg., over ν: [W/THz] , [W/m²·THz] , … , [W/(m²·sr·THz)] ,
over \tilde{\nu} : [W/(m²·sr·cm‾¹)],
over λ : [W/(m²·sr·µm)]
over E : [W/(m²·sr·eV)]
correction:
Linear B_ν = B_{ν,0} + a·τ :
L_ν = ( B_ν ( τ ) – a ) + [ L_{ν,0} − ( B_{ν,0} − a ) ] · exp(−τ)
= L_{ν,asymp} + [ L_{ν,0} − L_{ν,asymp,0} ] · exp(−τ)
asymptote: radiance lags behind by 1 unit of τ , ie.
L_{ν,asymp} = B_ν ( τ − 1 ) = B_ν ( τ ) – a
complete correction:
Constant B_ν :
L_ν = B_ν + ( L_{ν,0} − B_{ν,0} ) · exp(−τ)
asymptote:
radiance lags behind by 1 unit of τ , ie.L_{ν,asymp} = B_ν
—-
Linear B_ν = B_{ν,0} + a·τ :
L_ν = ( B_ν ( τ ) – a ) + [ L_{ν,0} − ( B_{ν,0} − a ) ] · exp(−τ)
= L_{ν,asymp} + [ L_{ν,0} − L_{ν,asymp,0} ] · exp(−τ)
= L_{ν,asymp} + L_{ν,0}^’ · exp(−τ)
asymptote: radiance lags behind by 1 unit of τ , ie.
L_{ν,asymp} = B_ν ( τ − 1 ) = B_ν ( τ ) – a
(again, see https://scienceopinionsfunandotherthings.wordpress.com/2025/12/09/for-asymptotic-radiances-ppia-linear-and-general-cases-wip-awaiting-final-proofread-double-check-diagrams-pending/ – it’s easier to read there)
Now just multiply by the |cos(θ)| (or cos(θ)) & integrate over solid ange Ω to get spectral flux density Fd_ν (The standard symbol is E_ν or E if not spectral, but that could be confusing…
upward and downward flux densities: Fd↑ , Fd↓
net upward flux density: Fd↑net
net downward flux density: = − Fd↑net )
d [ Fd(↑,↓)_ν ] = L_ν(↑,↓) · |cos(θ)| · dΩ
(you can think of radiance L as the intensity I per unit area facing the direction of L ( ie, (θ,ϕ)); multiplying by the |cosine of θ| gives the intensity per unit horizontal area. PS I’m skipping over some fine points on my L_ν(↑,↓) & θ notation…)
dΩ = sin(θ) dϕ dθ
but for PPIA we can just use dΩ = 2π sin(θ) dθ
and then *(if I remember right)* we get asymptotic values for the linear case:
Fd↑_ν = π (B_ν + ⅔·Γ_{Bτ})
Fd↓_ν = π (B_ν − ⅔· Γ_{Bτ})
Fd↑net = ⁴/₃· Γ_{Bτ}
L_{ν,asymp} = B_ν − Γ_{Bτ} · cos(θ)
where Γ_{Bτ} = ∂(B_ν) / ∂(τ_{vc}) (ie the lapse rate in terms of (based on) the Planck function and vertical optical depth)
(this is how I get the EELs for Fd (“Flotsam and Jetsam” ( https://www.realclimate.org/index.php/archives/2025/06/unforced-variations-jun-2025/#comment-834660 – https://www.realclimate.org/index.php/archives/2025/06/unforced-variations-jun-2025/#comment-834815 )) @ ∆τ = ± ⅔ (which one should be Flotsam and which one should be Jetsam?)
The decay of Fd toward its asymptote is more complex than a simple exp(−∆τ_{vc}), and depends on the directional distribution of L. Interesting case: if you have an inversion layer above a(n isothermal) cloud layer, for some levels of opacity, you can get net radiant heating in the uppermost part of the cloud and net net radiant cooling deeper in the layer, both due to the radiances from above. If the overlying atmosphere is not too opaque, but opaque enough, L↓ from near vertical can be dimmer (colder) than B of the cloud, while L↓ from closer to horizontal can be brighter (hotter) than the cloud’s B. The L closer to vertical penetrates deeper into the cloud; L farther from vertical is absorbed over a shallower layer. Compare to https://scienceopinionsfunandotherthings.wordpress.com/2024/12/10/directionally-averaged-radiance-and-the-semi-gray-skin-temperature-wip-awaiting-final-proofread-double-check-diagrams-pending/ (see last part: *†* …”Meanwhile, the anomalously brighter radiance near vertical penetrates deeper below TOA than the anomalously darker radiance near horizontal “…)
****(please post this in place of last submitted comment)****
complete correction, skipping the ν subscript: τ increasing in the direction the light L is going (you’re looking toward smaller τ in this context), from a point where L = L_0 , B = B_0 .
Constant B :
L = B + ( L_0 − B_0 ) · exp(−τ)
L’_0 = ( L_0 − B_0 )
L_{asymp} = B
—-
Linear B = B(τ) = B_ 0 + a·τ :
L = ( B – a ) + [ L_0 − ( B_0 − a ) ] · exp(−τ)
= L_{asymp} + [ L_0 − L_{asymp,0} ] · exp(−τ)
= L_{asymp} + L’_0 · exp(−τ)
= L_{asymp} + L’
asymptote: radiance lags behind by 1 unit of τ , ie.
L_{asymp} = L_{asymp}(τ) = B(τ−1) = B(τ) – a = B – a
…
d [ Fd(↑,↓) ] = L(↑,↓) · |cos(θ)| · dΩ
… for PPIA we can use dΩ = 2π sin(θ) dθ
“and then *(if I remember right)* we get asymptotic values for the linear case:”
L_{asymp} = B − ΓBτ · cos(θ) for θ = 0° to 180° , (L coming from zenith angle θ)
ie.:
L↑_{asymp} = B + ΓBτ · cos(θ) for θ = 0° to 90° (L going toward zenith angle θ)
L↓_{asymp} = B − ΓBτ · cos(θ) for θ = 0° to 90° (L coming from zenith angle θ)
Fd↑_{asymp} = π ( B + ⅔·ΓBτ )
Fd↓_{asymp} = π (B − ⅔·ΓBτ )
Fd↑net_{asymp} = π · 4/3 · ΓBτ
where ΓBτ = ∂B / ∂(τ_{vc}) (ie the lapse rate in terms of (based on) the Planck function and vertical optical depth)
mp = vertical mass path (measured downward from TOA) [kg/m²], and
k_a = mass absorption coefficient : [m²/kg]
τ_{vc} = vertical optical depth (measured downward from TOA) : [m²/m²]
—-
Generally, you’d want to do a numerical (approximating) integration – over a vertical coordinate (eg. z, p, p/p_{sfc}, mp, τ_{vc}, …
dp = −g · ρ · dz = −g · d(mp)
d(τ_{vc}) = k_a · d(mp) = μ_a · dz
β_a ≡ μ_a = Σ_i ( n_i · σ_{a,i} )
**(isotropic absorption σ_{a,i})**
…),
over solid ange Ω, and over the spectrum.
over a vertical coordinate: an obvious choice is to just directly use dL = ( B − L ) · dτ , ie. approximate the local atmospheric column as a set of thin-enough isothermal layers from i=0 to … (from TOA) (PS index i refers to the layer and to it’s upper boundary (lower boundary of the i−1 layer), ie. TOA is i=0. L↑(TOA) = L↑[i=0]… ; ∆mp[i] = mp[i+1] – mp[i] , …)
But a step up in sophistication would use an approximation of the profile as a set of linear segments, so the decay to a linear asymptote can be used, ie. (PPIA … TBC…) – another step up could use parabolic segments, etc… TBC… You could even use a set of B = linear superposition of sinusoidal terms; the L and Fd values for each term would sum (for each ν – ∆τ[i] for each ∆mp[i] will vary over ν, as will the shape of B(mp) ). But you might want to have values calculated for some vertical resolution, such that there might not be much more to gain from such levels of sophistication…
PS note – if you actually have a B profile with linear segments with sharp features, using the
(spectral) net radiant cooling, per unit mass (of air):
NCm_ν = 4π sr · ( B_ν – L_{ν,4π} ) · k_{a,air}
formula at mp[i] works; but for a good sense of how NCm_ν varies spatially, you’ll want higher vertical resolution getting closer to the sharp turns in ∂B/∂( τ_{vc}) (lapse rate discontinuities) and discontinuities in B(τ_{vc}) (eg. TOA). And/but If you are approximating a smooth curve with a series/set of linear segments, this formula will work ≈ okay (AFAIK) if the ∆τ_{vc}[i] = k_a[i] * ∆mp[i] are small enough, but as they get large, the you’ll get spurious nonzero NCm_ν results, due to the lapse rate discontinuities; the NCm_ν values between the discontinuities will go to 0 as they should, but you’re not calculating those values, and so a graph will only show the erroneous remnant nonzero NCm_ν results. So it’s better to calculate & graph
NCm[i] = ( Fd↑net[i] − Fd↑net[i+1] ) ÷ ∆mp[i]
[W/m² ÷ kg/m² = W/kg]
plotted at mp = mp[i] + ( ∆mp[i] ÷ 2 )
in that case…
discontinuity in B(τ_{vc}): use a ∆τ_{vc}[i] = 0 so that you can calculate two NCm_ν values at same τ_{vc}.
——- —
“parabolic segments”: behold the mighty quadratic asymptote:
B = a·τ² + b·τ + c
L_{asymp} = a·τ² + (b−2·a)·τ + [c−(b−2·a)]
Proof: show ∂L_{asymp}/∂τ = B − L_{asymp}
————– —
integration: over a vertical coordinate, over solid ange Ω, a over the spectrum: I’m guessing that last part may be the hardest. I don’t know how they handle these things in climate models, but I’d guess they use simplifying approximations, eg. – shuffling small bandwidths around by tiny amounts to make the spectra smoother – I read something like that. I imagine parameterizations for some non-PPIA situations (horizontally-patchy, vertically-thick clouds like towering cumulus/cumulonimbus would destroy the PP part)…
Barton, It turns out some other physicist right here on RC UV also has your bemusement or disagreement re “Not sure what you’re saying here. There is definitely atmospheric back-radiation; we can measure it with instruments”. It’s just down below for you to ponder its physics, asserting “On some …. (physics stuff) some therapy” to sharpen and show your science chops. Alternatively BPL you might prefer not to waste a bit of your life.
PO27 (No Reply button) I’ve only time to state I didn’t exactly ignore yours of a couple years back but that doesn’t mean that I’ll ever actually find time to study it, or this bit. Still it’s always there (I mean unless the State deletes it all and increases the chocolate ration from 27 milligrammes to 18 milligrammes).
Barry: “ I mean unless the State deletes it all and increases the chocolate ration from 27 mg to 18 mg.”
I see you are an optimist, Barry. I lived in the State that didn’t see the need to delete it -they would not allow you to post it in the first place. And it increased the chocolate ration, for adults like you, not to 18 mg, but to 0mg/month. So if you really yearned for the taste of chocolate, you would have to trade in your vodka ration for somebody’s kid chocolate ration.
Re Barry E Finch – no problem; I wrote for anyone who might be interested. I’ll just emphasize one point: computational costs/resource constraints aside, (I expect) higher resolution (vertical (optically thinner layers), angular (directional), etc.) is generally better.
(The vertical, horizontal, and temporal distribution of net radiant cooling will affect the climate as it requires/drives/balances/shapes tendencies in convective/advective/latent heating/heat flow etc. Which is why trying to balance CO2+CH4 et al.’s impact on GMST by reducing solar heating (at least without spectral and latitudinal/etc. selectivity) would still result in a changed climate (& also the O3, photosynthesis, stomata, pH effects) https://www.realclimate.org/index.php/archives/2025/11/unforced-variations-nov-2025/#comment-84254 1re https://www.realclimate.org/index.php/archives/2025/11/unforced-variations-nov-2025/#comment-842488 )
PS I try not to take it for granted that I am able to often enjoy ~ 300 – 1000 times that amount of chocolate daily.
patrick o twentyseven says
“PS I try not to take it for granted that I am able to often enjoy ~ 300 – 1000 times that amount of chocolate daily.”
Yep I would average about that most days. When I gave up smoking chocolate was the substitute strategy. I’m probably a bit addicted to chocolate but its less of a problem than tobacco plus I love the stuff.
Lucky to have the money be able to freely indulge. One should definitely not take these things for granted.
UAH TLT has been posted for November with a global anomaly of +0.43°C, down on Sept & Oct (+0.53°C) and pretty-much back down to the anomalies of the summer. (JJA averaged +0.41°C.)
This drop from October was all southern hemisphere (down to +0.27°C from +0.55°C) with the NH showing an increase (up to +0.59°C from +0.52°C.)
The TLT anomalies have been carving a different path from the SAT through the “bananas!!” period.
Smoothed-out, the global TLT anomalies peaked in March 2024 and have been dropping pretty consistently ever since. The NH ‘plateaued’ rather than peaked and began to drop quite strongly from September 2024 while the SH peaked in March 2024 dropping until Jan 2025 since when it has remained essentially flat. (See this graphed out in the yellow graphics at the foot of the The Banana!!! Watch page
Surface sends net radiation, sensible & water evaporation-condensing into troposphere. When it’s warmer it sends more of those and I just calculated the increase in water evaporation-condensing equals 0.7 degrees of warmer air if it really has been 9% more H2O gas for the +1.3 degrees and if the energy was used for thermal capacity, warming air, instead of being latent. I’ve no time to ponder whether or not that means anything about the TLT change vs surface temperature change (the surface is solid or liquid but the measurement is made nominally 2m above the surface so perhaps I’ve noted nothing of interest).
Been a long time since I commented here. Thanks for the continued efforts you all put in. I can’t find the answer to a question that occurred to me lately and I’d be very grateful if someone could point me in the right direction:
If Hansen is right and climate sensitivity is higher than IPCC puts it, leading to the acceleration he posits, does that mean that reductions in atmospheric GHGs would reduce temperature faster than current modelling?
Thanks in advance if anyone cares to help me out.
Good question. It depends on how complicated an answer you want.
A few comments back, Paul P posted this reference, which I found very useful:
https://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/fluid-mechanics-the-quintessential-complex-system/313B5D56A3BF8D4776D398A638A23C72
So one could answer you by saying “you gotta do the math”.
But I think you have to be clear about your question. Do you mean reducing CO2 after it is already added, or reducing the future value by reducing emissions now?
For example, if you have already melted all the ice on the planet and then you figure out a magic way to draw down CO2, you would have to create completely new models.
“Do you mean reducing CO2 after it is already added, or reducing the future value by reducing emissions now?”
Thanks for responding. I mean “reducing CO2 after it is already added”, although obviously the latter scenario would be preferable..
in Re to One Anonymous Bloke, 6 Dec 2025 at 11:36 AM,
https://www.realclimate.org/index.php/archives/2025/12/unforced-variations-dec-2025/#comment-842675
Dear Sir,
Thank you for your clarification that you ask how the climate will change after the “net zero” emissions are reached.
In this respect, MA Rodger cited on 23 Aug 2025 at 12:00 PM,
https://www.realclimate.org/index.php/archives/2025/08/unforced-variations-aug-2025/comment-page-2/#comment-838092 ,
two references, namely
MacDougall et al (2020) ‘Is there warming in the pipeline? A multi-model analysis of the Zero Emissions Commitment from CO2’
https://bg.copernicus.org/articles/17/2987/2020/
and
Borowiak et al (2024) ‘Projected Global Temperature Changes After Net Zero Are Small But Significant’
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2024GL108654 .
In the following discussion, he explained that these publications bring evidence that while global mean surface temperature (GMST) rise will likely stop a few decades after the “net zero” in emissions of non-condensing greenhouse gases (GHG) is reached, the Earth energy imbalance (EEI) will stay positive and the sea level rise (SLR) will continue for millennia.
A closer look suggests that there is a spread across climate models tested – some may show a longer continuing temperature rise after the “net zero”, some an almost instant temperature decline.
It is likely a result of different rates of two counteracting processes that decide about the outcome in each individual model – the natural CO2 drawdown from the atmosphere (that decides about the decline of Earth energy imbalance (EEI)) on one hand, and proportionality of the GMST change to the EEI (which may be, in my understanding, closely related to the climate sensitivity) on the other hand.
If so, I think that it may be well possible that if the “hot” models indeed apply for the present Earth climate, the “zero emission commitment” (ZEC) can be higher than that should be expected in case that the climate sensitivity is moderate.
As a layman, I will, however, definitely appreciate a comment (and, possibly, a correction) from someone more skilled in the art of climate science.
Best regards
Tomáš
Thanks for that reply Tomáš.
My question is more about any removal of CO2 (in the event that a mechanism could be invented to do this) than ‘net zero’, and the difference (if any) between what the IPCC might predict vs. Hansen’s higher climate sensitivity.
Does a higher climate sensitivity imply that changes resulting from a (purely theoretical) reduction in CO2 would happen faster?
I just found this link from 2008, wherein Hansen et al mention “a possibility of seeding irreversible catastrophic effects.” So perhaps the answer to my question is “probably not”.
https://arxiv.org/abs/0804.1126
One Anonymous Bloke, you really should ask jim himself. Too easy to be misled otherwise.
https://jimehansen.substack.com/
or email https://www.columbia.edu/~jeh1/mailings/
Do subscribe: Hansen is the ‘featured’ top item (2nd link}
https://csas.earth.columbia.edu/
Global Warming Has Accelerated: Are the United Nations and the Public Well-Informed? – https://www.tandfonline.com/doi/full/10.1080/00139157.2025.2434494
I see these categories under “Our Work”
-Climate Research
-Climate Data
-Public Awareness & Policy Solutions
–Our Children’s Trust
–Citizen’s Climate Lobby
–350.org
Thanks very much for that, Neurodivergent, I’ve subscribed to JH’s substack.
OAB,
Yes. And it doesn’t really have to be a “catastrophic” change like my example of all the ice melting; it’s a matter of the system becoming “different enough” from what we are working with now.
That’s the real question with the whole “acceleration” discussion. The temperature (GMST) is one of many characteristic of the system that respond to the increase in total system energy caused by CO2.
But the current models may not be able to predict a future GMST if, for example, the AMOC slows down to some arbitrary level. That’s the nature of complex systems as discussed in the reference I gave. They are complex; you have to do the math.
Thanks Zebra. “The temperature (GMST) is one of many characteristic of the system”
An insight I hadn’t considered let alone appreciated.
I’ll point out 1 quick thing for now which is “Pattern Effect”. If it’s real then it’s unstoppable because it’s a Done Deal. Assessed at =0.8 degrees over a few hundred years it requires no Forcing because it’s only that the ocean redistributes heat already in it and asserted it’ll reduce low cloud cover (over eastern tropical Pacific I think I recall but check that yourself). At https://www.youtube.com/watch?v=jlolDdnSHCE
Re: One Anonymous Bloke
In a vague, i.e. inconsequential sense – probably yes, but the real question whether it will be significant/comparable to the Hansen acceleration.
Your question seems to anticipate symmetry – but there is no reason to expect one – Hansen’s higher sensitivity requires strong positive feedbacks and/or crossing tippings points. And different feedback have different mechanism and thus different strengths and inertias. For example, you can start reducing CO2 conc., but the ice would be still melting with lower albedo countering the cooling expected from dropping CO2.
And to see why we should not expect symmetry – see the glacial-interglacial sequences:
they are triggered by the orbital cycles, but they cause negligible differences in the avg. solar radiation Earth’s receives (its all about heating in Arctic in summer, even if it’s globally balanced by cooling elsewhere or winter), so the massive difference in GMST between Ice max and T max – is almost exclusively thanks to the four positive feedbacks: ice albedo-T, water cycle-T, CO2-T and CH4-T, each different in strengths, geographic patterns, inertia etc.) and likely different responses on the way up as on the way down. Not surprisingly deglaciation phase is MANY times shorter than the glaciation phase.
So if even a symmetrical signal (orbital cycles) is not a guarantee of a symmetrical outcome (glacial-interglacial sequences), then what expect when even the signal (here: atm. Co2 changes) is not likely to be symmetrical?
So the only way to evaluate is to run the models. With the “current-modelling” from what I heard on RC (M.Mann?) – the net-zero human emissions CO2 – by allowing natural sinks to REDUCE atm. CO2 –
could ~ STABILIZE GMST. So obviously no symmetry there.
And the “IPCC” models are not as dependent on the positive feedbacks as is Hansen – so asymmetry in Hansen would likely be more pronounced.
And that’s not even talking about tipping points, which importance is tied SOLELY to their asymmetry
(if they were symmetrical, thus easily reversible – they wouldn’t be tipping points).
So the answer to your question is either trivial (“probably yes”), or non-answer (“we don’t know whether it will be significant or not”).
Given that, a more interesting question is – why do you ask? ;-)
Thanks for that detailed response Piotr. Your remarks about asymmetry are especially helpful. As to why I asked the question, it’s partly curiosity and partly to avoid a mistaken sense of optimism.
This is an interesting review of what’s wrong with AI ‘science” and how publication and peer review are being corrupted: Artificial intelligence research has a slop problem, academics say: ‘It’s a mess’. AI research in question as author claims to have written over 100 papers on AI that one expert calls a ‘disaster’ – https://www.theguardian.com/technology/2025/dec/06/ai-research-papers [I’m going to try to use blockquote for the following but if it doesn’t work, please know that the following is all quote:}
similar cases among AI researchers, who said their newly popular discipline faces a deluge of low-quality research papers, fueled by academic pressures and, in some cases, AI tools.
…. “team endeavors” run by his company, Algoverse. The company charges $3,325 to high-school students and undergraduates for a selective 12-week online mentoring experience – which involves help submitting work to conferences.
….
Meanwhile, students and academics are facing mounting pressure to rack up publications and keep up with their peers. It is uncommon to produce a double-digit number – much less triple – of high quality academic computer science papers in a year, academics said. Farid says that at times, his students have “vibe coded” papers to up their publication counts. | “So many young people want to get into AI. There’s a frenzy right now,” …. “It’s just a mess. You can’t keep up, you can’t publish, you can’t do good work, you can’t be thoughtful,” he said.
…. “You have no chance, no chance as an average reader to try to understand what is going on in the scientific literature. Your signal-to-noise ratio is basically one. I can barely go to these conferences and figure out what the hell is going on.” | “What I tell students is that, if what you’re trying to optimize publishing papers, you know, it’s actually honestly not that hard to do. Just do really crappy low-quality work and bomb conferences with it. But if you want to do really thoughtful, careful work, you’re at a disadvantage because you’re effectively unilaterally disarmed,” he said.
I think many researchers are sensitive to this situation. The year 2020 marked early usage of LLM and by 2o21 there was more widespread adoption. My own research findings, which I assune can be misconstrued as LLM-assisted, all happened prior to 2019 and I haven’t published anything since. Not that I did this intentionally, but as time goes by, I’d like to maintain the focus on the original published work to avoid the appearance of it being tainted by LLM vibe content.
Perhaps there will be a demarcation of B.C. – “Before ChatGPT”, and A.D. – “Anno Discursio” to indicate when a work was formulated or published.
Oops: after saying I’d try blockquote I failed to do so. It’s still all quote, fwiw. A valuable article on the problem with publishing and peer review today. The lies have it!
Just Have a Think (Dave Borlace) is turning the heat up a notch (as the actual heat continues to increase):
New analysis. How corporate overlords are unlawfully ignoring future climate impacts. – https://www.youtube.com/watch?v=YtS0j4hXCAs
“Fiduciary Duty is a phrase often touted by corporate CEOs and Wall Street types to justify their dodgy deals and questionable board level decisions. But Fiduciary Duty also involves safeguarding the LONG-TERM security of shareholders investments. Now a group of expert lawyers has published a report outlining how Exec Boards and Fund Managers are acting unlawfully if they do not fully factor in the impacts of the climate emergency. And the findings are quite challenging.”
Susan, good stuff, thanks. Unfortunately, with Pres. Trump’s plans for the next SEC head and his upcoming pick for Federal Reserve head to replace Powell next year beginning to leak, it looks pretty clear that climate change and corporate governance policies are going bye-bye until the Democratic Party can retake the White House.
C.C. Side Topic — A bright sign I think I can see is with the U.S. Supreme’s having repeatedly expanded the reach of the Executive Branch, there is going to be an opportunity for the D’s to do some real things, that if done right, could create positive changes (including on AGW) for the swathes of America being stepped on now in Gilded Age II.
I watched the following YouTube yesterday that (conveniently) does a reasonable job of outlining my philosophy on the subject. It’s an conversation with Marc Dunkelman hosted by John Avalon (39min). If you Susan, or anyone, does have time to watch it one of these days, weeks or months ahead, I’d love to hear it:
“America’s New Crisis: We Can’t Build (w/ Marc Dunkelman) | How to Fix It”
https://m.youtube.com/watch?v=drL2yh8fiQg&pp=0gcJCR4Bo7VqN5tD
David, why would climate change and corporate governance policies go bye-bye when we have many Democrat-run states?
Interesting video. They point out over and over that the reason Dems never get anything done on environmental or other “progressive” projects is too much government red tape, over-regulation, threat of lawsuits, excessive permit requirements, and all the things that Dems love and that Republicans have said for decades need to be reduced. They even say that Reagan’s ideas would benefit us – get government out of the way. They said that every time an environmental or progressive project comes up, out come the “progressive” NIMBYs to stop it.
After pointing out for a half hour all of the Democrat policies that prevent environmental and/or “progressive” projects to be built, they trot out their possible DEMOCRAT presidential candidates! So, they think the same group causing total dysfunction in government is going to somehow, magically, all of the sudden become competent and start successfully building things. Hilarious.
Then they insult Trump (the guy with bad hair in the WH) – the man who, more than any other in government, has a proven track record of successfully building large projects, and in the past 10 months working tirelessly to Make America Great Again.. He’s famous for fixing in 4 months what Democrats in NYC government couldn’t fix in many years:
https://www.forbes.com/sites/offwhitepapers/2015/08/24/donald-trump-and-the-wollman-rinking-of-american-politics/
Then, to top it all off, at 36:48, the 2 Democrats say they want to Make America Great Again. BWAHAHAHA!
Every day in the newspapers of blue holes across the nation, are articles about how the Democrats running the blue holes are going to fix public schools so the kids can read and write, make housing affordable, fix the homeless problem, fix traffic congestion, reduce crime, and on and on. Every year, in the same newspapers it is reported how all of the above and more are WORSE than the year before and they print the promises of the Democrat mayor, governor and city council members to make the problems better in the new year. It never happens – it just gets worse. -year after year for DECADES. Every election, all the voters in the blue holes STAMP THE DONKEY, and wonder why their blue hole continues to decline. You know the old saying about doing the same thing over and over and expecting different results……
The place is a joke. Neither side of US politics offers anything tangible rational or sane. Trump is a 21st century Mussolini fascist – and idiot in power with bullying thugs lording it over the rest
James Carvill throws his imprimatur into the ring. Comment by Peter Turchin
More recently, his tone has changed. In the latest essay, Out With Woke. In With Rage (Nov. 24, 2025), he has started to formulate a positive program for the Democrats:
JC (by nature?)
” I am now an 81-year-old man and I know that in the minds of many, I carry the torch from a so-called centrist political era. Yet it is abundantly clear even to me that the Democratic Party must now run on the most populist economic platform since the Great Depression.”
This is a big shift and it reflects the revolutionary times we live in. As I wrote in End Times, the Democratic Party did a great job suppressing its populist wing. This contributed to the defeat of its presidential candidates in both 2016 and 2024. What Carville calls “centrist,” actually, means “conducting policies for and by the ruling class.” Now that it has been overthrown, the
Democratic Party is ripe for the takeover by the left-wing populists (just like the Republican Part may be in the process of being taken over by the right-wing populists). And that’s what Carville essentially proposes.
Carville’s piece reads a lot like my posts in the series A Chronicle of Revolution. I doubt he read it; most likely, it’s starting to dawn on the former ruling party that “centrism” is dead. A few quotes:
“The people are revolting, and they have been for some time.”
“the rigged, screwed-up, morally bankrupt system”
“If you’re a student of history, the French Revolution is in the American wind.”
“Le peuple se lève.”
https://peterturchin.substack.com/p/the-return-of-the-left-populism
circling the drain with Peter Turchin
https://www.youtube.com/watch?v=d2VTHcUeCA0
Harvard tracks the youth voice
the mainstream media and political parties are viewed more as threats than assets.
many indicators pointing to widespread financial, emotional, and social strain.
expecting fewer opportunities, greater threats to job security, and diminished meaning in their careers.
Social trust is unraveling, as many young Americans avoid political conversations, fear judgment for sharing their views, and doubt that people with opposing perspectives want what’s best for the country.
reveals a generation under profound strain, as young Americans report deep economic insecurity, eroding trust in democratic institutions, and growing social fragmentation.
https://iop.harvard.edu/youth-poll/51st-edition-fall-2025
Pathological Self-Interest and Greed Rules America – a republic in name only
Mr. Know it All, I’m curious–do you actually believe what you wrote in this comment?
Thomas,
Yes, my comment is factual, much of it just repeating what the 2 guys in David’s video said about why Dems can’t get anything done. BPL below said that Dems were able to get things done in 1948. Probably true – the party hadn’t gone totally off the deep end at that time. They at least knew the difference between a male and female – that’s a low bar, but today they fail even that basic test, and that is a sad commentary. The consequences of such incompetence are catastrophic and we’re seeing them every single day and it will likely get worse before it gets better.
Was there something in particular that you thought I might not actually believe?
On Neurodivergent’s comment about young American’s economic insecurity, I wonder how much their poor education today in public schools (and in college) is contributing to that? If they’ve gone into debt to get useless degrees in various “studies”, and been indoctrinated into nonsense, can’t do the math to make change at a cash register, have mental breakdowns whenever someone expresses a viewpoint they don’t like, and basically learned little to nothing of value in public schools or in college, then I’d expect them to have a hard time economically.
Neurodivergent says they are also experiencing “eroding trust in democratic institutions”. I’d expect that when the Democrat party will not allow basic election security measures to be put in place. It isn’t just young folks who don’t trust our elections – most don’t – and it could be fixed, but just as with “progressive environmental projects”, Democrats will not allow it to be fixed. We know why.
KIA: BPL below said that Dems were able to get things done in 1948.
BPL: I don’t remember saying that. I think that was someone else.
KIA: They at least knew the difference between a male and female – that’s a low bar, but today they fail even that basic test, and that is a sad commentary.
BPL: What do you guys have against transsexuals? Do you know any? I do. I have a good friend who is trans (male=>female). She’s a nice, clever, friendly person and I value her friendship. She isn’t a threat to anybody.
Lay off the hate. It’s very off-putting.
KIA: the reason Dems never get anything done on environmental or other “progressive” projects is too much government red tape, over-regulation, threat of lawsuits, excessive permit requirements, and all the things that Dems love and that Republicans have said for decades need to be reduced.
BPL: We got a lot done. We no longer have pollution emergencies like Donora, PA in 1948. Rivers no longer catch on fire. We got lead out of gasoline. My home town of Pittsburgh no longer has a coating of soot all over the buildings and cars each morning. So your starting point is counterfactual.
In Re to Barton Paul Levenson, 14 Dec 2025 at 9:21 AM,
https://www.realclimate.org/index.php/archives/2025/12/unforced-variations-dec-2025/#comment-842861
Hallo Barton,
KIA may be partly right. I think that it might have been David who pointed to the following report
https://energyimplementation.github.io/implementation-report.pdf
summarizing “lessons to learn” from the difference between goals and achievments of the Biden’s administration.
Greetings
Tomáš
Copernicus has posted ERA5 SAT for November confirming the Nov anomaly at +0.65°C. This continues the marked increase in anomaly through Sept-Nov averaging +0.67°C. The unusually warm SH seen in both Sept & Oct (driven by particularly unusual Antractic anomalies) faded through Nov with the NH showing some of its normal Autumn upward wobble. (By way of comparison. through the Summer, Jun-Aug globally averaged +0.47°C.)
With that Sep-Nov upward wobble, the 2025 Jan-Nov average is now effectively identical to the 2023 Jan-Dec annual average. Which year has the edge depends on which anomaly base you choose. (Using 1850-1900, 2023=+1.481°C, 2025-to-date=+1.477°C, using 1991-2020, 2023=+0.6008°C, 2025-to-date=+0.6013°C.) So a December average of more than +0.60°C would put 2025 as the 2nd warmest year on record. The first seven days of December are showing an average of +0.54°C. But it’s early days.
Contrary to what you were intimating in late 2024 and early mid 2025, is this a quite understated acknowledgment that your expectations were completely wrong?
I hope so.
Also I can safely conclude now that it’s is also an additional acknowledgement that you’re seeing Jim Hansen as being correct in his expectations what would support (or not support) his general theory culminating in his last 3 published papers ….. about the 2023-2024 massive spike in global temperatures.
quoting
The Acid Test: Global Temperature in 2025
James Hansen and Pushker Kharecha 20 February 2025
The unprecedented leap of global temperature in 2023 and early 2024 exceeded 0.4°C (Fig. 1). We
and coauthors2 interpret that uniquely large warming as being due about equally to a moderate El
Nino and reduction of ship aerosols, with a smaller contribution from the present solar maximum
(our entire paper, including Abstract & Supplementary Material is available in a single compressed
PDF here). An “acid” test of our interpretation will be provided by the 2025 global temperature:
unlike the 1997-98 and 2015-16 El Ninos, which were followed by global cooling of more than
0.3°C and 0.2°C, respectively, we expect global temperature in 2025 to remain near or above the
1.5°C level. Indeed, the 2025 might even set a new record despite the present weak La Nina. There
are two independent reasons. First, the “new” climate forcing due to reduction of sulfate aerosols
over the ocean remains in place, and, second, high climate sensitivity (~4.5°C for doubled CO2)
implies that the warming from recently added forcings is still growing significantly.
https://www.columbia.edu/~jeh1/mailings/2025/Acid.Test.20Feb2025.pdf
And this one here too
2025 Global Temperature
James Hansen and Pushker Kharecha 15 April 2025
Abstract.
Global temperature for 2025 should decline little, if at all, from the record 2024 level.
Absence of a large temperature decline after the huge El Nino-spurred temperature increase in
2023-24 will provide further confirmation that IPCC’s best estimates for climate sensitivity and
aerosol climate forcing were both underestimates. Specifically, 2025 global temperature should
remain near or above +1.5C relative to 1880-1920, and, if the tropics remain ENSO-neutral,
there is good chance that 2025 may even exceed the 2024 record high global temperature
https://www.columbia.edu/~jeh1/mailings/2025/2025GlobalTemperature.15April2025.pdf
Hansen get’s it right yet again.
No wonder then his science papers are being referenced all over the place today, such as in the The 2025 state of the climate report: a planet on the brink
https://michaelmann.net/wp-content/uploads/2025/10/RippleEtAlBioscience2025.pdf
Barry E Finch, Piotr and Atomsk’s Sanakan must be feeling gutted and embarrassed about their anti-Hansen anti-peer reviewed science trolling all over again.
Neurodivergent (or whoever you are),
I don’t know what it is you think was “intimating in late 2024 and early mid 2025,” but I am not aware of any volte-face in my understanding of the cause of the 2023-24 “bananas!!” temperatures.
Hansen acolytes such as yourself should consider the dropping temperature anomalies through 2025 and see that they do not suggest the “bananas!!” resulted from positive forcings resulting from the 2020 marine pollution regs. And I was always of the opinion that such forcings could not be made to fit the evidential basis of the “bananas!!”
Hansen did hedge his bets in a paper this year insisting the “bananas!!” (or perhaps it was the post-2010 acceleration generally) could be due to reducing aerosols but could also be due to the appearance of cloud feedbacks. He argued that both would have the same implications for ECS. Feedbacks can disappear when the initiating forcing or temperature wobble is remove so cloud feedbacks remain on the table. But the aerosol forcing idea is dead.
As for Hansen’s “acid test”, my reading has always been that when Hansen & Kharecha said “we expect global temperature in 2025 to remain near or above the 1.5°C level.” this concerned monthly anomalies. If it did not, their follow-on statement “Indeed, the 2025 might even set a new record despite the present weak La Nina” doesn’t make a lot of sense.
2025 monthly temperatures didn’t remain near to +1.5ºC (dropping to +1.25ºC for July) and the 2025 annual anomaly has never looked like threatening to best 2024’s +1.6ºC.
All we have is 2023 with a “bananas!!” end to the year and 2025 with a “bananas!!” beginning vying for the 2nd place. Likely they will be =2nd.
Re: “Barry E Finch, Piotr and Atomsk’s Sanakan must be feeling gutted and embarrassed about their anti-Hansen anti-peer reviewed science trolling all over again.“
That’s nice, Mo Yunus, a.k.a. several other sockpuppet accounts. You’ve implicitly confirmed I was right about you. Regardless of how many sockpuppet accounts you use, you revert to your usual tactics, like idolizing Dr. James Hansen to the point that you angrily misrepresent even mild criticism of what he says.
Let me know when you can cogently address the actual criticisms of what Hansen said. I won’t hold my breath, though, since that would require you replacing your idol worship with the integrity and intellect needed to grasp topics like statistical tests for acceleration, selection bias, etc. You’ve never managed that across your several accounts.
Re: “[“]An “acid” test of our interpretation will be provided by the 2025 global temperature: unlike the 1997-98 and 2015-16 El Ninos, which were followed by global cooling of more than 0.3°C and 0.2°C, respectively, we expect global temperature in 2025 to remain near or above the 1.5°C level. Indeed, the 2025 might even set a new record despite the present weak La Nina.[“] […] Hansen get’s it right yet again. […] Barry E Finch, Piotr and Atomsk’s Sanakan must be feeling gutted and embarrassed about their anti-Hansen anti-peer reviewed science trolling all over again.“
The temperature drop from 2024 to 2025 is at least as large as the global surface temperature drop from 2016 to 2017. Similarly, the difference between the 2023/2024 average vs. 2025 is at least as negative as the difference between the 2015/2016 average vs. 2017. So no, 2025 did not set another record, nor is its temperature drop from 2023/2024 so small as to make 2023/2024 appear starkly “unlike the 1997-98 and 2015-16 El Ninos.”
Moreover, my criticisms of Hansen’s claims have not been about the global temperature anomaly for 2025 vs. for 2023/2024. My criticisms are instead about him using statistically unsound methods to claim acceleration of global surface warming, when statistically sound methods instead do not show statistically significant warming. I also previously noted that Barry E Finch gave a warming trend comparable to what your fellow Hansen idolizer Geoff Miell cited from Hansen:
You quoting Hansen on 2025 vs. 2023/2024 does not rebut Barry E Finch’s point on the multi-decadal warming trend, nor does it rebut my point on statistically significant acceleration. Like so many of Hansen’s fans, you don’t get the difference between shorter-term fluctuations vs. longer-term trends that are more statistically robust. And/or this great illustration of how you willfully misrepresent criticism of Hansen’s claims.
So 5 questions for you, Neurodivergent:
The answers to these questions are:
I predict you will not honestly address those questions, much like Geoff Miell repeatedly avoided pertinent questions:
Atomsk: “ Barry E Finch gave a warming trend comparable to what your fellow Hansen idolizer Geoff Miell cited from Hansen
I am not sure they actually “idolize Hansen” – they USE Hansen for their overriding psychological need – to prop up their ego by association with Hansen intellectual and ethical authority:
if I, [Multitroll, Geoff Miell, etc …), without much climate science background, can see (in Hansen) what top climate scientists can’t or refuse to see, then I must be very, very, smart and virtuous .
So they use Hansen as a drunkard would use a police-grade heavy flashlight – not for enlightenment, but to bash opponents head.
With supporters like that, who needs enemies?
Yeah, Piotr. It’s rather sad. It’s the same petty behavior Neurodivergent showed when posting under their Lleim sockpuppet account:
It’s gotten to the point that they don’t even see the implications of what Hansen is saying, as I illustrated with my 4th question. And as I said elsewhere, I think a lot of this is driven by misinformation from people like Leon Simons.
Re: “My criticisms are instead about him using statistically unsound methods to claim acceleration of global surface warming, when statistically sound methods instead do not show statistically significant warming.”
I mistakenly left out a word. That should instead read:
‘My criticisms are instead about him using statistically unsound methods to claim acceleration of global surface warming, when statistically sound methods instead do not show statistically significant warming acceleration.’
Re: “And/or this great illustration of how you willfully misrepresent criticism of Hansen’s claims.”
I mistakenly left out two words. That should instead read:
‘And/or this is a great illustration of how you willfully misrepresent criticism of Hansen’s claims.’
No honest attempt to address the questions, as expected. Just more evidence-free ranting and evasion, likely largely AI-generated.
https://www.realclimate.org/index.php/archives/2025/12/unforced-variations-dec-2025/#comment-842875
Atomsk’s Sanakan,
To be fair, I think the answer to your question 1) is “No, not yet.”
Hansen’s ‘Acid test’ only makes sense if it refers to something other than annual temperatures.. The quote “the 1997-98 and 2015-16 El Ninos, which were followed by global cooling of more than 0.3°C and 0.2°C” likely refers to the rolling 12=month values plotted-out by the blue trace in the graphic at the top of the Hansen & Kharecha posting linked above. The numbers used look like GISTEMP so the rolling 12-month peak and troughs (with end of period dates) would be:-
1998 … 8 .. +0.65°C
2000 … 2 .. +0.36°C
Cooling … 0.30°C
2016 … 9 .. +1.07°C
2018 … 4 .. +0.85°C
Cooling … 0.22°C
2024 … 8 .. +1.32°C
2025 … 11 .. +1.21°C (latest)
Cooling … 0.11°C so far
The problem with Hansen’s ‘Acid test’ is that it wasn’t explained very sharply. The general idea that the 2023/24 El Niño was not the entire driving force behind the “bananas!!” is likely true. However, Hansen’s ‘Acid test’ was going a step further by saying 2025 would see no cooling relative to 2024 (and could even see further warming), this predicated on the view that the extra ingredient was a forcing which would continue its work after the 2023/24 El Niño had come and gone. That ‘forcing’ explanation appears to be wrong.
MAR, I wonder if Hansen is half right: The year 2025 is indeed cooler than 2024 but you would expect this as the planet is moving out of el nino and into a la nina since September, But 2025 is still at least moderately warmer than what the climate community was expecting previous to 2023 isnt it? Therefore there may be some forcing continuing its work.
MA Rodger says
Hansen’s ‘Acid test’ only makes sense if it refers to something other than annual temperatures..
The problem with Hansen’s ‘Acid test’ is that it wasn’t explained very sharply.
That ‘forcing’ explanation appears to be wrong.
These flawed conclusions and allegations against Hansen’s acid test explanations must only apply to people who do not understand the simplicity of the information presented by Hansen.
Likely coupled with their inability or outright refusal to contact the author direct and seek his personal edification on their confusions.
The ignorant with too much to say, throwing sand in the eyes of genuine truth seekers, remains their own problem. Not Hansen’s.
https://jimehansen.substack.com/ or https://www.columbia.edu/~jeh1/mailings/
Common Sense dictates that Atomsk’s Sanakan, Piotr, and Rodger will unlikely be cured of their difficulties here.
Re: “Atomsk’s Sanakan,
To be fair, I think the answer to your question 1) is “No, not yet.”
Hansen’s ‘Acid test’ only makes sense if it refers to something other than annual temperatures.“
Thanks for pointing that out. If the test is interpreted as annual values for the two El Niño years, then enough time has passed to assess it. But it has the problems noted in my comment. If it’s instead interpreted in the way you suggest, then the Neurodivergent sockpuppet account was wrong when they said: “Hansen get’s it right yet again“. After all, the sockpuppet didn’t wait long enough after 2024 to know they’ve reached a trough, or at least long enough to match the wait time after 1998 and after 2016, as shown in your comment.
So they’re wrong either way. I probably shouldn’t have given them the benefit of the doubt by interpreting Hansen’s statements to fit with their assumption that enough time had passed to assess Hansen’s statements.
MAR My 1-minute 5-cents analysis worth. I still suggest strongly that Matthew H. England et al 2 papers about ocean surface winds (entirely different) have been significant over (1) 1996-2015 increasingly, not a step-change (2) 2023 the period covered by Matthew H. England et al 2nd Paper I refer to.
(1) Quote: “The record-breaking increase in Pacific Equatorial trade winds over the past 20 years had, until now, baffled researchers”. “When it does end, they expect to see some rapid changes, including a sudden acceleration of global average surface temperatures … It will be difficult to predict when the Pacific cooling trend and its contribution to the global hiatus in surface temperatures will come to an end,” Professor England says.”
“Recent intensification of wind-driven circulation in the Pacific and the ongoing warming hiatus” Matthew H. England, Shayne McGregor, Paul Spence, Gerald A. Meehl, Axel Timmermann, Wenju Cai, Alex Sen Gupta, Michael J. McPhaden, Ariaan Purich & Agus Santoso Nature Climate Change 4, 222–227 (2014) doi:10.1038/nclimate2106 Received 11 September 2013 Accepted 18 December 2013 Published online 09 February 2014 Corrected online 14 February 2014
My +0.065 degrees increase at 2014 by rotating 1995-2014 estimate I measured a couple months ago over 30 minutes from the pictorial at 21:38 at https://www.youtube.com/watch?v=agKayS6h6xA (I’ve been tracing various screen plots since 2013, zoomed up on 8×11 or 11×22 paper, GMST plots, Arctic Ocean albedos, ice loss, etc.) mid-east Pacific 60S-60N cooled average 0.20 degrees while GMST NOAA rose 0.30 degrees and 0.50 * 13% of Earth surface area I measured = +0.065 degrees GMST for a 20-year Unnatural Variation caused by humans warming the Atlantic faster than Pacific which imbalance caused Atlantic easterly surface winds to drive Pacific easterly surface winds faster than they been for at least the last 130 years (the reliable record length is what I understand). I assume that Atlantic wind effect on Pacific easterly surface winds has been diminishing or has stopped.
(2) https://www.youtube.com/watch?v=39T7bW7KA18
Re: “Likely coupled with their inability or outright refusal to contact the author direct and seek his personal edification on their confusions.“
That’s nice, sockpuppet account. Jim, you again give yourself away with your Hansen idolization. If you’d ever written a paper before, then you’d know the paper is supposed to be self-contained, such that it includes all the information needed to interpret it without needing to contact the authors. If Hansen and his co-authors did not include that level of detail, then that’s their fault, not the fault of the reader. Contacting the authors is supposed to be for things like requesting raw data, inquiring about collaborating, etc. It’s not supposed to be a get-out-of-jail-free card for the authors to write their paper in an ambiguous or unclear manner.
Re: “These flawed conclusions and allegations against Hansen’s acid test explanations must only apply to people who do not understand the simplicity of the information presented by Hansen.“
Then give an explanation of that information instead of just posturing. Given an interpretation of what Neurodivergent quoted from Hansen that:
1) matches what Hansen said
2) has enough time pass to assess whether Hansen is right
3) confirms Hansen is right
Conditions 2 and 3 are from your sockpuppet account Neurodivergent saying: “Hansen get’s it right yet again“. I gave an interpretation that met condition 2, arguably condition 1, but contradicted condition 3. MA Rodger gave an interpretation that met condition 1, but contradicted conditions 2 and 3. My point is that there is no plausible interpretation that meets all three conditions, thereby debunking what Neurodivergent said. And given your track record of evidence-free evasive posturing across your sockpuppet accounts, you’re not going to give an interpretation that meets all three conditions.
Barry E Finch,
I recall that you have raise this ‘wind-driven-circulation’ thing before and specifically cited England et al (2014). At publication, England et al were setting out a potential cause of that slowdown in AGW which was exercising everybody back then.
Matthew England is well-published but I don’t see any updates that reinforce the findings of England et al (2014). Note he is a co-author of Li et al (2022) ‘Recent acceleration in global ocean heat accumulation by mode and intermediate waters’. (‘Mode’ isn’t a particularly well-known term here. It does have a Wiki page – Mode Water.) Li et al conclude by saying:-
The rate of GMST increase under AGW will be greatly dependent on ocean warming and mechanisms therein. Famously, El Niño’s are an example of this dependence leading to the large ENSO wobble. And there may have been a different but similar/associated outpouring of ocean heat that resulted in the “bananas!!”. Myself, I did start a search for signs of it but didn’t get very far.
It is now a couple of years since the “absolutely gobsmackingly bananas!!” proclamation but as yet no published papers that I have seen pointing strongly in the direction of ocean heat being the cause, even from Matthew England, although there may be something hiding away in his long publication list. (For the record, I didn’t see England et al (2025) as providing the long-term wobble that would fit the “bananas!!”.)
Matthew England may perhaps be saying some eye-opening stuff in that hour-long YouTube you link-to, but sadly I’ve presently not the time/inclination to be searching through it without more to go on.
Jim: ” Common Sense dictates that Atomsk’s Sanakan, Piotr, and Rodger will unlikely be cured of their difficulties here.”
Quite a statement from somebody who just arrived on this group ;-)
If it walks like a Yebo, quacks like a Neurodivergent, swims like a Pedro and poops in public places like a Dharma, then it is a Jim.
And Atomsk simple questions still await – changing your face won’t change anything in that.
More info on mode water, which is imp0rtant in stratification and metastability, consider in lakes —
Autumn: As the surface cools, the epilimnion (a mode water layer) deepens. Eventually, the entire lake cools to ~4°C, triggering the autumn overturn. After overturn, the whole lake becomes, temporarily, one large mass of mode water (isothermal).
Winter: In ice-covered lakes, inverse stratification may set in.
Spring: After ice-off, the surface warms to 4°C, triggering spring overturn. As warming continues, wind mixing creates a new, warm mode water layer at the surface (the new epilimnion), re-establishing summer stratification.
So overturning is the reset button that mixes the whole lake. Mode water is the uniform slab of water that is either a major part of a stratified lake or the entire lake just after the reset.
Wish that oceans were this predictable in overturning, which is complicated by salinity, Coriolis, and the obvious strong tidal forcing effects — exaggerated immensely by density differences in stratification!, which are further incommensurate with seasonal cycles, thus creating an erratic pattern.
MARodger “ to Matthew England may perhaps be saying some eye-opening stuff in that hour-long YouTube you link-to, but sadly I’ve presently not the time/inclination to be searching through it without more to go on”
I share your sentiment. And I would like to expand it in a more general comment to improve the effectiveness of discussion here and elsewhere:
a link to a video does not prove your point. Yes, it is OK to give a link to Youtube video for people looking for a general explanation of some question they have little familiarity with – but for specific technical argument – a link to 1hr+ long video is a non-starter – I would have to waste an hour of my life to listen to a talk covering things that I likely already know to get to the promised morsel of insight hidden somewhere there.
The proof of showing how a video clip supports one’s specific argument lies on the proponent – you have to point to the minute where the referenced video covers your point – after all you must have watched this video and it is your, not my, argument.
Particularly that too often (and I am NOT saying this about you, Barry) it is a Hail-Mary pass by the deniers and Multi-trolls, who having failed to defend their point – throw in link to a video, as if all the vindication of their position they needed was there.
And a link to a you-tube is not at all like a link to a paper – that – unlike a youtube link, has been peer-reviewed and I can quickly look at the abstract, graphs and conclusions before deciding whether is was worth my time or not.
They all understate here but such is the nature of scientific blogs and they are harsh too on others.
Pete Best,
“They all understate here”
If you wish to claim people understate the climate problem, you have to provide some specific evidence they are doing this. For example MAR and AS are both obviously warmists, but have posted lengthy comments sceptical of some of the more extreme claims made on the climate issue.
Where exactly do you think they are getting it wrong? Please understand just quoting someone who thinks climate change will be at the extreme end or whatever, is not adequate. You have to show in detail where MARs and AS’s specific claims and reasoning are wrong.
Personally, I think climate change could potentially be towards the upper level of estimates but I’ve seen some really extreme claims that simply lack credibility. Not an expert myself but some of this stuff is still just obviously very speculative and isn’t thought through.
Pete Best’s comments are just the usual substance-free tone trolling. One way to deal with that sort of person is to ask them pertinent questions, give them sufficient information to answer the questions, and then see whether they address the questions. Trolls expose themselves by not honestly and cogently engaging with the questions. Typically they just bravely run away.
I’ve asked the questions in this comment above. So I’ll leave it to the trolls to expose themselves, as the geologist and science journalist Peter Hadfield (a.k.a. Potholer54) noted:
https://michaelmann.net/wp-content/uploads/2025/10/RippleEtAlBioscience2025.pdf
This paper seems to be stating it’s getting a bit desperate but you wouldn’t know it trying to read the posts here .
It’s a scientific blog and I get that and I know the world appears to be presently warming between 0.2C and 0.3C presently. James Hansen is a sincere scientist so I see no reason for the IPCC to try and get his work. From being published
‘If you wish to claim people understate the climate problem, you have to provide some specific evidence they are doing this. ….
Where exactly do you think they are getting it wrong? ‘
The usual bit–trying to model AND predict the next El Nino. “Getting it wrong” is perhaps not the right wording, as the skill level has yet to produce anything useful. Researchers are still trying though, with many papers featuring machine learning approaches.
I don’t recall why I’d be “gutted” but I might have lost track. May 2023 I questioned the EEI 1.33 w/m**2 because I’d gotten “Karina von Schuckmann et al’s latest 0.78 w/m**2 (I eye balled 0.88 w/m**2 for last 4 years off her plot with her recent talk), so I looked into it and found of course that was correct that EEI had increased a lot (I recall 0.90 w/m**2 over 20 years) so I updated my notes and started pondering with the new information and I posted:
“OK, I didn’t realize that the EEI has been increasing at a rate as high as the 0.5 w/m**2 / decade. I’ll have to take another look at my quick calculation 5 years ago of 0.20 degrees / decade + 0.06 degrees / decade**2 for +GMST if I ever find the time (it was based of course on what I’d read as the prior increase in EEI since 1970)” so if I was “gutted” it would have been in May 2023 and some people just aren’t keeping up to date because it’s December 2025 now. I wasn’t “gutted” in May 2023, I just updated my notes. It’s interesting.
“Neurodivergent”: “Barry E Finch, Piotr and Atomsk’s Sanakan must be feeling gutted and embarrassed about their anti-Hansen anti-peer reviewed science trolling all over again.”
What can be asserted without evidence can also be dismissed without evidence,
So stop giving the neurodivergents bad name, the same way you have tarred the reputation of a renewable expert Pedro Prieto by appropriating his name and pushing your claims as him.
The search engines and AI won’t know that you have been an imposter and will forever associate his name with your troll production. Way to pay a “tribute” to him, as you defended your practice.
As for “feeling gutted and embarrassed” – isn’t this what you feel looking in the mirror in the morning? If I were you – incapable of understanding what you read and on what you base your derision toward others, and seeing your opponents constantly running circles around you – I would have felt “gutted and embarrassed” too.
Hansen’s words do not mean what you think they mean, nor do posts of Barry, Atomsk or me.
And no, you can’t hide your intellectual and ethical shallowness by draping yourself in Jim Hansen (the “ authority by association“).
Nor will we pull our punches just because you now appropriated a “ neurodivergent ” label – nobody, save perhaps Susan ;-), will go:
“ Atomsk, for God’s sake – stop battering that neurodivergent boy with falsifiable arguments and with your “Yes or No” questions – see you’d made that poor boy cry ”
Now, go away or we shall taunt you a second time. Fetchez la vache!
Piotr: “As for “feeling gutted and embarrassed” – isn’t this what you feel looking in the mirror in the morning? If I were you – incapable of understanding what you read and on what you base your derision toward others, and seeing your opponents constantly running circles around you – I would have felt “gutted and embarrassed” too.”
This guy probably doesn’t feel gutted and embarrassed. He / she obviously has some sort of superiority complex. Some sort of narcissistic psychological issue. He/ she probably genuinely believes they are right. Neuro divergent may in this instance mean genuinely neurodivergent. You and I would be gutted and embarrassed (and would tidy up our act) but dont assume everyone would be. But he / she does indeed misinterpret what people say.
Nigel “This guy probably doesn’t feel “gutted and embarrassed“.
not at a conscious level
Nigel: “ He / she obviously has some sort of superiority complex.”
that masks the deep seated inferiority: ” A superiority complex is an inflated self-image masking deep-seated inferiority, leading to arrogance, dominance, and devaluing others”
Nigel “Neuro divergent may in this instance mean genuinely neurodivergent. ”
Should an internet troll be considered “neurodivergent”, or just a pathetic type, who hasn’t achieved anything meaningful in life – so he tries to bait opponents, because this would give him the sense of control – thus make his life not pathetic (would a pathetic person be able to “own” supposedly smart people ?). Does it make the multi-troll -neurodivergent ?
Don’t think so. Being a pathetic human being is not something he can’t do anything about, as would be the case for a real neurodivergent.
So the Occam’s razor suggests multitroll adopted this handle to be cute – look, if I call myself “neurodivergent” then it must be ironic – thus proving that I am anything but
Since photons in the infrared wavelengths are being tossed about (or manufactured or re-emitted or down-welling or back-radiated) I’m NOT going to participate in that, but throw in mechanical work being done by the temperature difference between surface and space. The invention will not fix the world but might evolve into producing useful work in specific situations. But one component could be much more useful.
“Scientists Generate Power At Night By Passively Beaming Heat into Outer Space. It’s “Like Solar Cells in Reverse”
UC Davis engineers have invented a Stirling engine that captures Earth’s escaping heat to generate power from the night sky.”
The secret sauce is the coating that the device exposes to the open sky.
“The top plate (warm side) uses a paint that is highly emissive in the infrared. This allows heat to pass directly through a clear section of the atmosphere, called the atmospheric transparency window (between 8 and 13 µm). The heat radiates directly into space, cooling the panel far below the ambient air temperature.
“It doesn’t actually have to touch space physically, it can just interact radiatively with space,” Munday explains.”
That from here, and the article links to the underlying Science Advances research article.
https://www.zmescience.com/future/scientists-generate-power-at-night-by-passively-beaming-heat-into-outer-space-its-like-solar-cells-in-reverse/
But there are now a number of different ways researchers have invented to create coatings (or materials) that radiate their heat in that transparency bandwidth range. Science had a paper maybe ten years ago about a plastic film with embedded glass nanoparticles that radiate in the range. That can be manufactured by the mile on standard plastic sheet machinery. Others have worked on paints and other coatings that do the same.
Another team found a way to treat wood such that the resulting product doesn’t just radiate to space, but it’s stronger, too.
https://www.science.org/content/article/engineered-wood-radiates-heat-space-potentially-slashing-cooling-costs.
And another one from just last month: “Researchers at the University of Sydney and start-up Dewpoint Innovations have developed a nanoengineered polymer paint-like coating that can passively cool buildings and capture water directly from the air — all without energy input.”
https://www.techbriefs.com/component/content/article/54267-this-paint-can-cool-buildings-without-energy-input
These won’t fix “the world” either, but since IR was a topic, it’s worth thinking about buildings and other structures in hot, sunny, arid places where there’s little water vapor at night to block those IR photons and their trip to space, taking away fairly substantial heat from what’s under the treated surface. Could be a lot of use for that. Zero power cooling.
For whatever reason, the first time I’d read of the plastic film I mentioned above, my first thought of a practical use was shaded shelter for livestock in places where subsistence farming along with goats or cattle happens in hot areas.
More specifically a case would be around the Arabian Sea where they’re first predicting brief episodes where wet-bulb temperatures lethal to large mammals without cooling. If some type of cattle shed with a passively-cooling roof was inexpensive enough, and durable, it could mean the difference between a living farmer without any surviving livestock or a farmer continuing to survive without becoming another refugee. Some kind of earthen walls and maybe a more transmissive mass on the roof so cooling at night would persist a bit in the day – guessing on it, but that could make a difference.
Here’s that first piece I’d seen – 2017.
https://www.science.org/content/article/cheap-plastic-film-cools-whatever-it-touches-10-c
I think something would have to be done to prevent the film or paint from working during the day.
The difficulty with passive cooling under extreme wet bulb conditions is that they occur with an extremely high dew point. This means that nearly all of the cooling power would go into condensing water instead of cooling the air. If the condensed water was collected, it could be useful in a desert climate, however.
John, didn’t you just describe a dehumidifier?
Zebra, that’s not what I understood b fagan to be describing. He seems to be talking about passive cooling for an animal shelter by coating the top. That’s not my idea of a dehumidifier.
Sorry, John, I was trying to be too clever (but making a serious point).
My understanding of the problem with high wet bulb temps is that the body can’t cool itself through evaporation.
Conventional dehumidifiers produce thermal energy themselves, of course, but this technique would avoid that problem, so even if it didn’t remove thermal energy (or just a little), it should still be beneficial for the occupants. (?)
Hi guys,
I was bringing them up based on the usefulness of these IR-tuned passive radiative materials in general and then, again because the extreme wet-bulb risks are greatest in a lot of areas where low-income pastoralists and/or small farms with cattle or goats are still common.
One thing they’d face that could drive them off their land into big cities is loss of all their livestock, and building sheds with high-powered fans and A/C systems is a non-starter for most of that set of people. So my speculation for a critical use for the material, specific to avoiding large-scale abandonment of lifestyle and locale due to what might be one or two days in summer where there are daytime hours where temperatures are lethal without kind of artificial cooling.
So how to design for low-cost and effectiveness without much or any power. If the passive radiator can do a big piece of the cooling work, survivability of person and their livestock may be enhanced – avoiding a migration trigger for as long as possible while the rest of us end the greenhouse emissions overall.
Another article on the wet-bulb risk , and a visualization tool courtesy of the folks at Columbia Climate School.
https://news.climate.columbia.edu/2020/05/08/fatal-heat-humidity-emerging/
Looking at the scale of the at-risk sections of the globe, this should be something made ready soon if it’s not already being tried..
https://news.climate.columbia.edu/2020/05/08/interactive-map-daily-maximum-wet-bulb-temperature/
And it turns out KPMG put out something this summer discussing the materials, opportunities, etc.
https://assets.kpmg.com/content/dam/kpmg/cn/pdf/en/2025/06/power-free-passive-radiative-cooling-industry-development-and-market-insights.pdf
Being able to accomplish significant cooling without power, just by choice of building material or coatings is going to be reeeeeeally helpful worldwide.
Hi Steven and John,
I did some poking around and there’s a lot of stuff looking at how to -actually- use the transparency window rather than just my thought of gluing the film onto sheets of corrugated iron. Unsurprising since cooling becomes increasingly important and avoiding extra energy demand and local heat retention are both bonus points. So here are a few links and they seem to also have some interesting other links to more work.
PS on the condensed water, John, that’s part of what they describe in the research written about in the NASA Techbriefs link (last in my initial post). Other research on using passive cooling, including at least one of the ones below, also looks to avoid the problem of condensation – the good news is this is a lot of engineering and construction-trade level work so again, this won’t Fix The World, but it seems likely it will help specific use cases and needs.
This one has passive heating AND cooling. Published: 12 September 2024 in Nature Communications
Passive isothermal film with self-switchable radiative cooling-driven water sorption layer for arid climate applications
https://www.nature.com/articles/s41467-024-52328-z
This one for passive cooling even in high temperatures and significant (up to 100%) humidity. Published 2019 in Optics Express
Nighttime radiative cooling in hot and humid climates
They calculate results but also did some experimental testing of a simple physical mock-up where they got this: “We experimentally demonstrated nighttime radiative cooling in summer with RH from 53–100%. Even at a hot summer night at T-ambient = 29 °C with RH = 100%, we achieved radiative cooling of 5.2 °C below ambient. With a more sophisticated photonic design, a similar, if not better, cooling performance could be achieved in hot and humid climates at daytime.”
https://opg.optica.org/oe/fulltext.cfm?uri=oe-27-22-31587
And this one – 2022 in International Journal of Thermofluids
Potential of hybrid radiant cooling with infrared-transparent membranes to improve thermal comfort in hot and humid climate
https://www.sciencedirect.com/science/article/pii/S2666202722000775
Emph mine:
I’m glad they’re upfront about the low power densities; the value seems to be for (in present-day developed-nation context) niche applications.
Apologies for breaking Susan’s Law, but I have to push back on this claim:
On part 1: depends on the surface which would otherwise be there. Maybe if It’s a low-emmisivity surface like dry rock? (depends on spectrum of albedo) … OLR would be maintained if a perfect emitter at just the right temperature Tc replaces a surface with Th and lower emmisivity ε (in the window*) with
window ∫ ε · B_h· dν = window ∫B_c· dν
i = c,h
E_{Ti} = k·T_i
B_i = (2h·ν³/c²) ÷ ( exp(−hν/E_{Ti}) – 1 )
( https://en.wikipedia.org/wiki/Planck%27s_law )
But actually the ε may need to be lower to make up for the technology’s ε=0 of the outside the window* (*ε=1 of the technology) because the atmosphere’s window has transitional bandwidth.
On part 2: No. It increases the fraction by taking that heat flow out of the atm. window and sending it to do useful work, which is then dissipated ultimately as heat, which now must still find a way out of the Earth System.
Back to part 1- as it is with the atmospheric heat engine ( https://www.realclimate.org/index.php/archives/2025/07/unforced-variations-july-2025/#comment-835660
https://www.realclimate.org/index.php/archives/2025/07/unforced-variations-july-2025/#comment-835665
), solar power – thermal (max conversion efficiency at Th → T_Sun, but max net energy flux into collector at cold Th ), PV (open circuit V vs short circuit I, … more…), and wind turbines (complete conversion of flow through swept area requires that flow = 0 (complete deflection by pressure); Betz limit),
having a nonzero conversion efficiency requires Tc get cooler, which reduces the OLR; equilibrating to the brightness T of the window maximizes the conversion efficiency, but then there is no flux to convert. (The window OLR / heat flow into Th = Tc/Th ideally. Eg. 6 W/m² supply could come from 300 K Th, 270 K Tc (1-Tc/Th = 90%), 60 W/m² inflow, 54 W/m² emitted.) (Ideally, the window of ε=1 would cover the bandwidth over which the emitted W/(m²·cm¯¹) would be greater than the sfc Fd↓ (Tc still warmer then brightness temperature of ↓flux density @ sfc), with ε=0 outside of that (includes SW bandwidth, so would work in sunlight).
… But probably not a big issue given the likely niche application.
Fd = flux density
correction:
having a nonzero conversion efficiency requires Tc get cooler, which reduces the OLR; equilibrating to the brightness T of the window’s Fd↓@sfc maximizes the conversion efficiency, but then there is no flux to convert. (The window ( emitted Fd↑ − Fd↓@sfc) / (heat flow into Th) = Tc/Th ideally. Eg. 6 W/m² supply could come from 300 K Th, 270 K Tc (1-Tc/Th = 90%), 60 W/m² inflow, 54 W/m² = emitted Fd↑ − Fd↓@sfc) . (Ideally, the window of ε=1 would cover the bandwidth over which the emitted W/(m²·cm¯¹) would be greater than the sfc Fd↓_ν (Tc still warmer then brightness temperature of ↓flux density @ sfc), with ε=0 outside of that (includes SW bandwidth, so would work in sunlight – wait, that might make up for the OLR dimming ).
(Above was about/from: https://www.zmescience.com/future/scientists-generate-power-at-night-by-passively-beaming-heat-into-outer-space-its-like-solar-cells-in-reverse/ )
…
Actually, I forgot to include the reflected …
(specular (like a mirror) or diffuse (Lambertian is the most diffuse, right? https://en.wikipedia.org/wiki/Lambertian_reflectance ) … or retroreflective (I’ve observed a bright spot around the shadow of my head in some natural surfaces (gravel, grass), so it’s not only an artificial thing; also glories ( & https://en.wikipedia.org/wiki/Brocken_spectre )… ))
… radiance L from the sfc.
Generally, even in the atmospheric window, only some fraction of the Fd↑ (flux density) from the sfc gets through the atmosphere to become part of the OLR at TOA; but of course maintaining the OLR without other changes requires maintaining either that Fd↑(sfc) with the same angular & spectral distribution of L_ν, or perhaps a different Fd↑ with compensating angular &/or spectral distributions of L_ν, such that the same transmitted Fd↑(sfc) gets to TOA… Anyway, for maintaining the window OLR, window ∫∫∫ t(θ,ϕ)· [ ε(θ,ϕ)·B_h + L_{reflected}(θ,ϕ) – B_c ] · ½·sin(2θ)·dφ·dθ·dν = 0 . where sfc @ T=Tc, ε=1 replaces sfc @ T=Th, ε.
( ½·sin(2θ) = sin(θ)·cos(θ) )
With a sufficient inversion & GHE, sfc LW albedo could increase OLR. OTOH, with sufficient cloud cover, there is no direct effect from the sfc on OLR. If the highest clouds are warmer than the sfc, they … etc.
PS hey, these look cool!
https://opticsthewebsite.com/OpticsCalculators
https://photonicsproject.org/calculators/blackbody/
…“or retroreflective (I’ve observed a bright spot around the shadow of my head in some natural surfaces (gravel, grass),”… it’s subtle.
“It was almost a pre-bunking effort,” — Daniel Swain, climate scientist with University of California Agriculture and Natural Resources
Not paywalled…
“EPA erases references to human-caused climate change from websites
The agency revamped its webpages to feature natural causes of rising temperatures such as the Earth’s orbit.”
By JEAN CHEMNICK | 12/09/2025 06:18 AM EST
E&E News by Politico
https://www.eenews.net/articles/epa-erases-references-to-human-caused-climate-change-from-websites/
Off Topic: Lee Zeldin is drawing slowly increasing calls for Pres.Trump to fire him by some conservative groups aligned with MAHA movement over EPA’s sweeping efforts to relax, ignore, postpone, remove rules for regulating a number of toxic chemicals. Maybe a sliver of hope? A Christmas wish perhaps for a man who has overseen such extraordinary damage in so many ways in ten months? (lol, no comments needed, just a momentary spark of fool’s hope by me)
UN environment report ‘hijacked’ by US and others over fossil fuels, top scientist says – https://www.bbc.com/news/articles/c1w9ge93w9po
begin quote ->
“I thought we had gone beyond the point of recognizing that when you burn oil, this big, thick black stuff comes up, and it probably isn’t good, especially when you try and breathe it in,” said Dr David Broadstock, with the Lantau Group, and one of the report’s lead authors.
“It’s kind of pretty obvious, and yet we’re still seeing parties wanting to pursue the increasing scale of production of such things,” he told BBC News.
Since taking office President Trump has sought to boost fossil fuel production and roll back US commitments to fight climate change, calling for the country to be a global energy superpower with cheap and reliable resources.
He has also sought to get the US courts to overturn the idea that carbon dioxide is a danger to public health. His government has also followed up with efforts to restrict or limit the efforts of international bodies that set out to tackle warming.
This year has seen efforts at international plastics negotiations, at the international maritime organisation and during COP30 to strike out language that states that climate change is a major issue requiring the world to move away rapidly from fossil fuels.
The disagreement over the Global Environment Outlook report will raise concerns about future negotiations for the Intergovernmental Panel on Climate Change reports as these studies are seen as the bedrock of global efforts to limit global warming. <-end quote
https://youtu.be/4-a-qeMyaPE?si=ooH2TWSDn8jn5mMK
Hansen makes some good points I think.
An example of expert herd mentality
is the response to our global warming
acceleration paper. The next day,
these experts unanimously condemned
our paper in the media.
[and on blogs including RC]
Not one of them discussed the physics in
our paper or explained what was wrong.
Instead, there were ad homonym remarks.
“Hansen makes lots of mistakes. Hansen
exaggerates. Hansen is not collegial.”
For many years over a decade now, James Hansen has been asserting in public, repeatedly :
‘What we witness now is scientific reticence on steroids’
Ignore him. Maybe the truth will go away.
…says the sockpuppet account still bravely running away from questions that shows it’s wrong.
https://www.realclimate.org/index.php/archives/2025/12/unforced-variations-dec-2025/#comment-842796
“And then I say I trust the crowd because I haven’t got any views of my own.”
~Penrose
https://www.youtube.com/watch?v=7HE7xgiFXRE
Q:What is it that you disagree with your colleagues about?
If I disagreed strongly with my colleagues about it,
then I probably shouldn’t be thinking it,
because of the wisdom of the crowds;
they believe that they’re the ones that are most likely incorrect if everyone else believes something different [sic]
Q: But how is it that you can maintain this level of, maybe belief is not the correct word, conviction, credence in your own ideas, despite being criticized by colleagues? How do you psychologically deal with that?
It’s just that the arguments are wrong. I mean, I don’t see any good arguments against my point of view.
The thing about the cosmology is that it’s a crazy idea. My idea is a crazy idea,
and I admit it’s a crazy idea. But you need something crazy because the conventional ideas
don’t work.
And I think people just sort of go with the crowd.
I’m just not persuaded by going with the crowd. It doesn’t seem to me… I mean,
There are lots of things I don’t know anything about.
And then I say I trust the crowd because I haven’t got any views of my own.
Reply to JCM
The “fallacy of popular opinions” is the Ad Populum fallacy (Appeal to Popularity/Bandwagon Effect), which incorrectly claims something is true, good, or right just because many people believe it, ignoring evidence or logic. It exploits our desire to fit in (bandwagon effect) and uses emotions or majority agreement as proof, even though history shows the majority can be wrong (like the Earth being the center of the universe). This fallacy is common in advertising, politics, and everyday debates, relying on conformity rather than facts.
How it works:
Argument Structure: “Everyone/Most people believe X, therefore X is true”.
Leverages Emotion: Plays on the human tendency to conform or belong (the “bandwagon effect”).
Avoids Evidence: Substitutes popularity for solid reasoning or factual proof.
In climate science debates, a related error occurs when consensus or model agreement is treated as equivalent to established fact. Many key quantities — such as cloud feedbacks, aerosol forcing, ocean circulation, and regional climate responses — are not directly observed but estimated through models with evolving assumptions. When provisional outputs are presented as settled facts, and model agreement is mistaken for empirical confirmation across the full climate system rather than a limited metric like global mean temperature, this becomes a form of reified consensus rather than evidence-based reasoning.
What’s happening is not just appeal to popularity. It’s a stacked set of epistemic errors that get collapsed into “we have the facts” when, in reality, we have provisional, model-dependent estimates.
The Fallacy of Reified Consensus (also called “Consensus Reification” in philosophy of science)
Definition:
Treating a scientific consensus — especially one derived from models, assumptions, and parameterisations — as if it were a settled body of empirical fact, rather than a provisional framework subject to revision.
In short: Turning agreement into evidence. Calling this out is not anti-science — it’s pro-scientific humility. The disarming in climate dialogues is manifold in sidestepping the “facts”.
We have Argument from Authority (Ad Verecundiam) – “The IPCC says…” – “97% of scientists agree…”
This is used improperly when:
uncertainty ranges are downplayed
dissenting evidence is dismissed without engagement
authority substitutes for falsifiable validation
Accusations of trolling thrown about and allegations that sockpuppets have no facts arguments or scientific support. It does not get more anti-science anti-reason and fallacious than that low step. The bastion of scoundrels and deeply engrained institutional censorship wins the skirmish and lose the war against humanity and truth. The anonymous nobody accusers are the Concern Trolls here.
Model Platonism (Informal but accurate) A category error where:
climate models are treated as the climate itself
internal consistency is mistaken for empirical completeness
This is especially relevant for:
cloud feedbacks
aerosol forcing
ocean heat uptake
regional circulation
Models are tools, not observations. The opposite is deployed by trolls to disarm confuse and manipulate people.
The Fallacy of Precision
Presents narrow confidence intervals, average means, precise numerical targets (1.5°C, 2.0°C),
exact timelines when the underlying system is in fact chaotic, poorly constrained, and dependent on assumptions that change over time
Complexity and Precision does not equate to Accuracy. In Reasoning or Math. Incompetent anonymous Concern Trolls tells you it does. The authoritive experts look on and say nothing.
Surrogate Validation Fallacy is an important one. Definition:
Claiming a model is “validated” because it reproduces one aggregate metric (e.g. global mean temperature), while failing across many coupled components (clouds, ice, precipitation, circulation, regional variability).
Matching one curve only does not mean the work, “the experiment” is understanding the system correctly. When everything else fails real world observations then the one that appears to match is also wrong.
The Trolls and silent expert observers can’t cope with facts evidence nor reason and logic. It just doesn’t compute within their distorted world view anymore. They have become what they rail against.
N: a related error occurs when consensus or model agreement is treated as equivalent to established fact.
BPL: I’m pretty sure you don’t know what “scientific consensus” means.
Neurodivergent @14 Dec 2025 at 9:09 PM
His / her comments are an entire forest of strawman arguments, and non sequiturs and evidence free accusations against nameless people and muddled, confused thinking, and inflammatory claims (ie:trolling). Which is somewhat ironic.
Just more evidence-free ranting and tone trolling that’s likely largely AI-generated. All to bravely run away from evidence and questions that debunk a trolling sockpuppet account.
https://www.realclimate.org/index.php/archives/2025/12/unforced-variations-dec-2025/#comment-842796
https://www.realclimate.org/index.php/archives/2025/11/raising-climate-literacy/#comment-842607
If crowds were wise we wouldn’t have Trump treating the US as his personal protection racket, and climate denial would not exist. We wouldn’t have ready access to high powered killing machines. We wouldn’t blame victims. We wouldn’t have extreme income inequality. We wouldn’t enable toxic waste to give gazillionaires more att our expense. etc. etc. etc.
Both GISTEMP and NOAA have posted for November.
GISTEMP gives November with an anomaly of +1.22°C, a little up on October’s +1.19°C.
The NH saw a big rise (+1.47°C to +1.69°C) which is to be expected as northern summers are taking longer to cool off under AGW, while the SH saw a not-quite-so-big drop (+0.91°C to +0.76°C).
2025-to-date (+1.20°C) is running cooler than Jan-Nov 2024 (+1.29°C) but warmer than Jan-Nov 2023 (+1.17°C). This makes a 2nd place 2025 a certainty in GISTEMP, requiring Dec25 to average +91°C or less to drop 2025 down to 3rd warmest. The last time a GISTEMP anomaly that low was seen was Jan 2023.
Meanwhile NOAA gives November with an anomaly of +1.18°C, a little down on October’s +1.19°C, the NH rise (+1.65°C up from +1.52°C) being a bit smaller than the SH drop (+0.71°C down from +0.87°C).
The difference in the Jan-Nov average anomalies for 2025 & 2023 is smaller in the NOAA numbers making a 2nd place for 2025 pretty unlikely, requiring a Dec anomaly above +1.31°C.
Please note, global and hemispheric temperature anomalies are with respect to the 1901-2000 average.
Do not confuse this data with the Paris set +1.5C anomaly and current tracked GMST
https://yaleclimateconnections.org/2025/12/3rd-warmest-on-record-again-november-2025-keeps-a-hot-global-streak-going/
What exactly are you posting about – is it significant posting the exact temperatures from satellites etc
This article states that the past 3 years are the warmest on record and 2023 and 2025 will tie for second warmest.
Are you suggesting the warming is significant ?
Copernicus
The global three-year average temperature for 2023–2025 will likely exceed 1.5°C above pre-industrial levels for the first time.
November 2025 was the third-warmest November on record globally, keeping 2025 on track to be the second- or third-warmest year recorded.
NOAA’s NCEI November 2025 was Earth’s third-warmest November in analyses of global weather data going back to 1850, …………………… NOT 1900-2000 RANGE THAT RODGER USES
.
.
.
According to NOAA, the year-to-date period (January-November) has been the 2nd-warmest on record for the globe, running just 0.01°C (0.02°F) above the January-November value for 2023 and 0.1°C (0.2°F) behind the value for 2024.
.
.
.
James Hansen and Pushker Kharecha 15 April 2025
Abstract. Global temperature for 2025 should decline little, if at all, from the record 2024 level
.
Absence of a large temperature decline after the huge El Nino-spurred temperature increase in
2023-24 will provide further confirmation that IPCC’s best estimates for climate sensitivity and
aerosol climate forcing were both underestimates.
Specifically, 2025 global temperature should remain near or above +1.5C relative to 1880-1920
.
>WHICH IT HAS
.
https://www.columbia.edu/~jeh1/mailings/2025/2025GlobalTemperature.15April2025.pdf
Dr Gilbz isn’t too happy about it either
https://youtu.be/VF9M-sDW7HI
Pete Best: Thanks for the link. I wish people would stop attacking anyone who dares to deviate from their exact interpretation of what is going on. I find your contributions reasonable and reality based. Attempting to lower the temperature and stop arguing over minutiae is admirable. The neverending hostilities are not a useful contribution and make this comment section less useful than it might be.
Once again, as representatives of the supposed ‘extremes’ Hansen, Mann and Schmidt are not very far apart compared to, for example, Russ Vought and Trump’s predatory liars.
Dr Gilbz is more than not happy. Her mental health has been in the bin.
03:43 – (Climate) Academia is broken
https://www.youtube.com/watch?v=mw6miP-v1Ds&t=223s
She Quit!
Communicating the science is the way
that I can have the most impact. Of
course, scientific research is essential,
but we know enough to act already.
Talking about the changes that need to
happen and sharing what we know
already about climate change is
really for me a much better use of my time
and energy.
Dr Gilbz
A Breath of fresh air. The youth are the future. She’s spotted the critical gap. The weakness.
Pete Best I’m bemused about your question if it’s to MAR. Just looks like plain vanilla relevant asserted quantities to me. Whenever I decide to take a butcher’s at such I challenge any that look incorrect, perhaps ask for citations where not provided, and/or note alternative measurement analyses of the same, perhaps something related, else I don’t comment because I’ve no comment (unless I’m whimsical and thought of a chocolate quip),
People here keep on producing charts of warning (it’s not cooling now is it).
https://www.independent.co.uk/news/uk/home-news/christmas-traffic-congestion-aa-b2887258.html
Nothing changes but I’m thinking oh the facts will change people’s minds because it hadn’t yet bit one day it will get so warm it’s going to.
The whole edifice of climate change, climate science and the world as it is tells me you will be posting these charts of warming for a long time to come and little to nothing will change because it costs too much, ppl cannot afford it, it’s not good enough or it’ breaks down.
A few Teslas and Chinese EVs won’t change anything
A delightful ditty about physics, climate, scientists and weather [found via Gavin Schmidt’s Bluesky]
Call Me Charney: A GFD Parody
https://www.youtube.com/watch?v=qbMwX2uo23U
The trumpster dumpter administration’s planned destruction of the National Center for Atmospheric Research (NCAR), which has been a foundation to US atmospheric science scientific research for over 60 years is utterly vile. It is as anti-science, anti-research, anti-data, and anti-facts as it gets. As is anyone who supports the action to deny basic scientific facts that have been extensively and unequivocally peer-reviewed. The action is also destroying America scientific leadership in the world.
https://www.usatoday.com/story/news/politics/2025/12/16/trump-dismantle-national-center-atmospheric-research-climate/87798771007/
I have read that many foreign research institutes and their host countries have initiated programs to recruit American scientists abroad. It is reverse brain drain as scientists leave in order to avoid ideological control of science. Not all American scientists have the option of moving abroad, but those US research facilities not under direct US government control are also being attacked.
Still taking that in (NCAR threats, and the intemperate lies about reality). It’s hard to believe. I keep thinking they can’t shock me any more, but I was wrong.
My only hope is that public outrage will be so high they’ll put it off.
News flash – a large bipartisan deal to fund most of the government, a so-called minibus bill, has been stopped dead in its tracks by two Senators from Colorado who said Congress must prevent Trump from dismantling NCAR if they want the deal to go through.
Dan’s use of the word “vile” is a spot-on description of this latest plan to conduct yet another malicious act of destruction of federal science efforts by the Trump Administration.
Hopefully, people will get out their phone and call their U.S. Representative and both of their state’s U.S. Senators to make one’s thoughts known. Particularly those of us with Republican representation.
And all because the State government won’t play ball with pardoning Tina Peters.
Everything that follows is based on measured atmospheric data, not model projections or policy scenarios.
What this means, in simple physical terms
Earth is currently out of energy balance. More energy is coming in than going out.
Right now, that imbalance is about +1 watt per square metre (W/m²). That may sound small, but spread across the entire surface of the planet, it represents an enormous and continuous heat input. Because the oceans absorb heat slowly, much of the warming this imbalance causes has not happened yet. But, it is already locked in.
Even if greenhouse gas levels stopped rising tomorrow, significant additional warming is unavoidable because the system has not yet equilibrated.
Climate forcing is the driver — not targets or pledges
Climate forcing is the push that causes warming. Greenhouse gases reduce how much heat escapes to space.
Doubling CO₂ causes about +4 W/m² of forcing. Today, total human-caused forcing is already around +2.5 to +3 W/m², even after subtracting the cooling effect of aerosols. The key point is warming follows forcing, not political timelines.
The forcing is not slowing — it is accelerating
Over the past 15 years, the growth rate of greenhouse gas forcing has risen sharply, reaching about ~0.5 W/m² per decade. This is not a projection. It is measured from atmospheric data.
That rate is far higher than what would be required to stabilise temperature, let alone reduce warming.
Reality is tracking RCP8.5 — not RCP2.6
The IPCC’s “safe” pathway (RCP2.6) assumed a rapid slowdown in greenhouse gas forcing growth.
That slowdown never happened. Measured forcing growth has diverged dramatically from RCP2.6 and instead tracks close to RCP8.5, the high-end emissions scenario once described as the “worst case” scenario.
This means staying below 2 °C is now implausible. Staying below 1.5 °C is already gone. Impossible. While “Net Zero by 2050” does not align with physical reality under any plausible interpretation of current forcing trends.
Carbon capture cannot close the gap
In theory, carbon capture could compensate for the difference between reality and RCP2.6. In practice, using current technology, the cost of capturing that gap would already be $2.4–5 trillion per year (as of early 2023)
And the gap — and the cost — keeps growing. This alone makes the Net Zero framing non-credible at planetary scale.
The key chart is missing for a reason
For 25 years, Hansen and colleagues have published a simple, transparent chart showing actual greenhouse gas forcing growth — the so-called “colorful chart”. (See link)
Despite relying on the same underlying data as the IPCC, this chart does not appear in IPCC reports.
The omission matters because the chart shows, unmistakably, that:
Forcing growth accelerated
The climate problem worsened
Policy narratives did not match physical trends
The central scientific failure
Climate models and scenarios are useful — but data must come first. When measured forcing trends are ignored or downplayed, projections become detached from reality.
The result is false reassurance, built on modelled scenarios that assume future actions and technologies that do not exist at the required scale or with demonstrated feasibility.
The situation now is fundamentally different
This is no longer an early-warning phase. We are already in the consequence phase. Warming is accelerating. Feedbacks are activating. Irreversible thresholds are closer.
The Decisions made in the next 5–10 years will shape outcomes for centuries — not because of targets, but because of physics.
Ending where the responsibility lies
If policymakers misunderstand the severity of the situation, scientists share responsibility when they allow unrealistic scenarios to be treated as credible futures.
The data are clear. The forcing is rising fast. The trajectory is wrong.
…………………
Inspiration and data source
Abstract
The growth rate of greenhouse gas climate forcing has increased rapidly over the past 15 years, reaching about 0.5 W/m² per decade. This measured acceleration shows that reality has diverged sharply from the IPCC’s low-emissions scenario (RCP2.6) and instead tracks close to the high-emissions RCP8.5 pathway. As a result, limiting global warming to below 2 °C is now implausible. The continued rise in forcing demonstrates that mid-century “net zero” targets are not aligned with physical reality. Transparent, data-driven analysis of climate forcing must take precedence over scenario-based projections if dangerous interference with the climate system is to be properly understood.
Authors James Hansen Pushker Kharecha Dylan Morgan
21 November 2025
https://www.columbia.edu/~jeh1/mailings/2025/ColorfulChart.21November2025.pdf
Data. it’s nice to have that laid out. Essentially everybody who comments here knows and understands those physical science things and more for months, years, decades variously (has a worthwhile physics education). I had no idea that there has been some 25-year conspiracy or whatever within the U.N. IPCC framework to exclude the work of James Hansen. Are you able without risking Actionable comment to pin it down to groups of persons or to the Governments of countries with specifics (not just “Petro States blah blah). Real checkable specifics? Seems interesting.
Real checkable specifics?
Sophies Choice.
25 years of Hansen output.
https://www.columbia.edu/~jeh1/mailings/
Critical commentary by IPCC authors who quit.
Plenty of useful data, detail and analysis in this study: Carbon Brief. Analysis: What are the causes of recent record-high global temperatures? Zeke Hausfather 10.12.2025 | 3:00pm
In this article, Carbon Brief explores four different factors that have been proposed for the exceptional warmth seen in recent years. These are:
A strong El Niño event that developed in the latter part of 2023.
Rapid declines in sulphur dioxide emissions – particularly from international shipping and China.
An unusual volcanic eruption in Tonga in 2022.
A stronger-than-expected solar cycle.
Carbon Brief’s analysis finds that a combination of these factors explains most of the unusual warmth observed in 2024 and half of the difference between observed and expected warming in 2023.
However, natural fluctuations in the Earth’s climate may have also played a role in the exceptional temperatures, alongside signs of declining cloud cover that may have implications for the sensitivity of the climate to human-caused emissions……
https://www.carbonbrief.org/analysis-what-are-the-causes-of-recent-record-high-global-temperatures/
Nigelj, your description of the likely causes of recent record-high global temperatures is missing the recent paper of Matthew H. England et al (MEetal). Why? As soon as I saw the rapid rise of GMST late Spring 2023 I thought “That’s the ocean because the ocean modulates surface-air temperatures because the ocean has ~all the heat content that is significant on these times scales (land is tens of thousands of years and longer responding). So only ocean shoaling can do this much (or a big part of it). MEetal found that in 2023 the El Nino had an effect (presumably unusual and powerful) in shifting a High-Pressure system which slowed northern ocean surface winds and MEetal noted that rising sea surface temperatures (SSTs) followed this around the northern oceans. Why not being considered as a significant contributor?
My “northern ocean(s)” S.B. “North Atlantic Ocean”. I forgot that since July.
Barry E Finch, Ocean shoaling sounds plausible to me. The problem is with thousands of papers being published almost weekly its possible Carbon Brief are not aware of the paper you mentioned. Might be worth your time emailing them.
Just on another tangent. When I looked at the carbon brief graph of global surface temperature I notice the so called pause after 1998 the temperatures eventually drop slightly below the long term linear trend line then after 2015 temperatures creep above this line a little. Just eyeballing the graph, hope the eyes are working properly. Makes me wonder if whatever caused the so called pause which appears to be some sort of ocean and wind driven process might have now reversed. However the recent warming spike clearly has a combination of causes several of them anthropogenic with potential to accelerate the warming trend.
“Ocean shoaling” is an alternate way of describing the behavior behind ENSO.
Nigelj,
I wasn’t particularly ‘blown away’ by Zeke Hausfather’s CarbonBrief piece. To me, it read as the same exercise as performed through the months-gone-by and coming to very similar conclusions – that the “bananas!!” resulted from a conspiring set of miscreant climatic stuff. That may be so. But it doesn’t feel a robust conclusion to me.
I think we can say that the dropping global temp anomalies do point to there being no forcing from aerosols as a major cause of the “bananas!!” That still leaves the possibility of a cloud feedback amplifying a natural wobble. Or it may be the “bananas!!” are what El Niño’s have come to look like now, with or without a potential big feedback.
My graphical comparisons of the “bananas!!” with previous El Niño haven’t been updated for quite a while & for clarity I’ve posted new graphics showing global, NH & SH GISTEMP through the 1997/98, 2015/16 & 2023/24 El Niño’s HERE – Posted 18th December 2025.
The global anomalies 2022-25 (top graph) don’t show such a seriously massive difference from 2014-17 or 1996-99 wobbles. The warm wobble in 2023 wasn’t actually that big but it did arrived very early, didn’t cool that much through 2024 with another big warm wobble following in late-2024 and signs of yet another warm wobble (size yet unknown) in late-2025.
These warm wobbles are in the main actually the NH autumns not cooling down as quickly as in the past and this means NH autumns usually have anomalies rising faster than the rest of the year, and this now big enough to feature large in the global values. They can be less of a feature in La Niña years. And plotting out these NH anomalies (middle graph) shows these warm wobbles in all their splendour.
The SH (bottom graph) shows that the initial bit of those rising global anomalies was in the SH autumn with the SH (so far) has not seen a lot of cooling reversing that wobble. Note that the cooling 2014-18 wasn’t particularly rapid either. But the SH warmth does seem to e hanging on, although I’d speculate on another mechanism at work. It may be a one-off event but maybe not – I do wonder if there is a speculative SH wobble through the SH winter beginning to appear, but saying this, such thoughts are somewhat fanciful so far.
Recent analyses, including those summarised by Carbon Brief, offer plausible short-term contributors to the exceptional warmth observed since 2023. These discussions are useful. However, they are often received and deployed as more definitive than the underlying uncertainties allow.
In particular, large uncertainties remain in aerosol forcing, aerosol–cloud interactions, and cloud feedbacks. Given the size of these uncertainties, conclusions about the relative contribution and sufficiency of individual short-term factors should be treated as provisional rather than settled.
This matters because some analyses implicitly treat model-based expectations as stable reference points, while unresolved uncertainties — and peer-reviewed challenges to those expectations — receive limited direct engagement. Hansen et al. (2025), whether ultimately right or wrong, present a peer-reviewed analysis that makes falsifiable claims and argues that recent observations may point to a structural underestimation of climate sensitivity in current models.
Their argument does not deny aerosol or cloud uncertainty; it incorporates it. The claim is that uncertainty does not simply add noise, but may implicate core model assumptions — particularly the combination of aerosol masking, ECS tuning, observed forcing, Earth’s energy imbalance, ocean heat uptake, and paleoclimate constraints.
By contrast, analyses that focus primarily on additive short-term factors operate largely within existing model expectations. If uncertainties are large, confidence should scale accordingly.
Short-term forcings can explain anomalies only if the underlying model framework is sound — Hansen’s work questions that assumption, and that challenge still needs direct engagement.
On “uncertainty” and “paleoclimate constraints” mentioned and me trying to push work onto others does anybody know what I wondered the last couple years, where did Jim Hansen’s 3.0 W/m**2 for GHG forcings of warming from the LGM at AGU 2011 come from and what better science since 2011 improved it to Jim’s newer 2.25 W/m**2 for GHG forcings that therefore has increased Climate Sensitivity by 13% (not insignificant) additional t the 40% increase due to LGM GMST increase was ~7.0 not ~5.0 degrees?
Reply to Barry E Finch
does anybody know what I wondered the last couple years?
I do not. I know of no one who does. Observations of your commentary suggests you do not know either, but perhaps you’re still trying. So, good luck.
“Data” says 22 Dec 2025:
“ Reply to Barry E Finch – “does anybody know what I wondered the last couple years?”
I do not. I know of no one who does.
Well, if you DIDN’T CUT your “quote” JUST as Barry explained what he was wondering about, perhaps it wouldn’t be such an impenetrable mystery to your brilliant mind. Here you go:
Barry: “does anybody know what I wondered the last couple years where did Jim Hansen’s 3.0 W/m**2 for GHG forcings of warming from the LGM at AGU 2011 come from
Data: I do not. I know of no one who does. Observations of your commentary suggests you do not know either
So your oh so witty, repartee only shows how much your observations/ethical integrity.are worth.
Now, quickly change your handle, so the new one can deny the responsibility for … “Data”‘s manipulation.
The great scientist Richard Feynman famously ridiculed scientific reticence.
with reference to the late Wally Broecker, in Sophie’s Choice Jim Hansen writes
“…the quality of Wally that I admire most was his courage to speculate.
Progress in science depends on people who have the knowledge and the courage to attempt an
interpretation of available data, which are always incomplete and contain measurement flaws.
This quality is the antithesis of scientific reticence. Sometimes Wally’s proposed interpretations
were criticized as a “house of cards,” and, indeed, they often came tumbling down, but, even in
such cases, he stimulated research. Other scientists criticized his proposal, flaws were exposed,
and improvements were made – that is how scientific progress is made rapidly.”
A Global warming projection. Assumption of at least a moderate El Nino beginning in 2026
leads us to the projection in Fig. 5, with global temperature reaching a minimum at or above
+1.4°C within several months and then rising to a record global temperature of about +1.7°C in
2027. This new record will occur only four years after the 2023 El Nino, so additional,
underlying, global warming at the accelerated rate of 0.31°C per decade is only about 0.1°C.
Fig. 5. Projected global temperature in 2026 and 2027
https://substackcdn.com/image/fetch/$s_!y_Vt!,w_1456,c_limit,f_webp,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2F480bbefc-da3a-4870-8609-dc60d57e5438_777x418.png
Numerous models and evidence point toward an El Nino beginning in the second half of 2026.
For example, Fig. 4 is an ensemble of projections of the current NOAA NCEP model.
We can use the well-founded expectation of this upcoming El Nino for a further test of
global warming acceleration.
Warm or cold anomalies need to exceed 0.5°C for several consecutive months to qualify as
El Nino or La Nina. Beware that rapid global warming of the past half century is perturbing
the quantitative significance of Nino3.4. The strongest El Nino relative to its surroundings
was the 1997-98 El Nino;
the 2015-16 and 2023 El Nino strengths are exaggerated by the effect of global warming
on the Nino3.4 index, which also diminishes apparent strength of recent La Ninas.
Two years ago (29 March 2024) Hansen et al projected that global warming in the
then-ongoing El Nino would rise much more than in prior El Ninos, raising global
temperature to at least +1.6°C, and that temperature after the El Nino would fall only
to +1.4°C (see Fig. 2).
(Expectation of unusual warming was based on realization that a long-term global
cooling effect of aerosols had recently shifted to warming, as we will discuss further
in an upcoming post.)
Consistent with this prior projection, Hansen et al expect a minimum 12-month running-
mean temperature of about +1.4°C to be reached in the first half of 2026, after which
global temperature should begin a rise that will continue into 2027, reaching a new record
high, as discussed above.
Global temperature of +1.47°C in 2025 relative to 1880-1920 is the 2nd highest in the period
of instrumental data, about 0.1°C cooler than the 2024 record high (Fig. 1) in the GISS analysis.
(Hansen et al assume the exact December temperature has imperceptible effect on the
2025 temperature in Fig. 1).
The 3-year (2023-2025) temperature is +1.5°C relative to 1880-1920. Hansen et al will provide
details on the geographical and temporal temperature change in a communication in early
2026.
Abstract. Global temperature in 2025 declined 0.1°C from its El Nino-spurred maximum
in 2024, making 2025 the second warmest year. The 2023-2025 mean is +1.5°C relative to
1880-1920.
The 12-month running-mean temperature should decline for the next few months,
reaching a minimum about +1.4°C. Later in 2026, we expect the 12-month running-mean
temperature to begin to rise, as dynamical models show development of an El Nino.
We project a global temperature record of +1.7°C in 2027, which will provide further
confirmation of the recent global warming acceleration.
Source
https://www.columbia.edu/~jeh1/mailings/2025/GlobalTemperaturePrediction2025.12.18.pdf
https://youtu.be/rI8z6A0c5Q4
Kevin Anderson once again demonstrates that it is very easy for the political and economic perspective on climate change and how to tackle it to delude itself and tell the public all is well and going in the right direction.
The reality iof the issue is that until we address human behaviour and its implications we arnt going fir enough
Reply to Pete Best
Kevin’s data explanations and political insights are first class. Unfortunately COP isn’t failing because of bad leadership or bad science. COP is failing because consensus-based sovereign bargaining is structurally incapable of governing a physical system.
COP outcomes are therefore merely performative in nature. We cannot expect different results from repeating the same approach that has dominated these negotiations for thirty years. Focusing on COP30 Brazil failures highlights the impossible 100% Consensus requirement among 192 nations with individual critical needs. The original UNFCCC Rules ensure failure.
That failure is structural not political. And not a failure of science but in it’s application through compromised agreements among players, big and small, all kicking the can down the road. The COP structure needs root and branch reform. As does the IPCC structure–not the science they are to make wise judgements about.
Kevin is indeed right. But there is no venue or process where it can made to work. Only the chattering classes where nothing gets done.
Heard some climate news on BBC radio last night and did some searching for more details. Apologies if you already know. Things look grim in the US across the board.
At the AGU 2025 Fall Meeting (December 15–19), climate researchers adopted notably cautious and strategic messaging in response to journalists. This reflected a hostile political climate in which the Trump administration proposed closing major facilities such as NCAR and dismissed climate research as “alarmism.”
In several high-profile sessions, federal scientists avoided potentially politicized terms like “fossil fuels” and even “climate change.” During the 2025 Arctic Report Card briefing, for example, NOAA’s acting chief scientist addressed Arctic warming in terms of “long-term environmental observations,” without explicitly naming human drivers.
Instead, researchers emphasized data continuity and measurement reliability, underscoring that observational records remain accessible and scientifically robust rather than drawing policy-linked conclusions.
AGU also encouraged disciplined media engagement, advising scientists to rely on precise, concrete metrics (such as specific glacier retreat rates) and to minimize jargon.
As discussion of once-taboo topics like solar geoengineering increased, scientists framed these issues through shared ethical frameworks focused on responsible research and governance, avoiding personal advocacy.
Despite public caution, many researchers simultaneously engaged in internal advocacy, including coordinated efforts to lobby Congress to protect climate research infrastructure such as NCAR.
During the 2025 Arctic Report Card press conference at the AGU Annual Meeting, NOAA’s Acting Chief Scientist Steve Thur was questioned by journalist Barbara Moran regarding the agency’s stance on the causes of climate change
……………………….
On Tuesday, Russel Vought, President Donald Trump’s Office of Management and Budget Director, said the administration plans to close the National Center for Atmospheric Research, a Colorado research facility that has operated since 1960. The facility “is one of the largest sources of climate alarmism in the country,” Vought said in a post on the social media site X.
And this year, unlike the other years since 2006 when NOAA published the first Arctic Report Card, the agency declined to issue a news release about it.
Thur, asked if NOAA will continue to publish report cards in the future, said the agency will continue the work that goes into the annual documents.
“What I would say in response to that question, is that we’re here today and that we have released the 2025 version,” he said. NOAA has continued its long-term environmental observations in the Arctic, both with satellite observations, he said. “So I think one of the things that the community can rely upon is that our efforts to continue to observe the planet will remain present,” he said.
Thur also demurred when asked whether NOAA still stands by the statements about fossil fuels made by the agency’s prior administrator, Rick Spinrad. When last year’s report was issued at the end of the Biden administration, Spinrad said the changes in the Arctic were directly related to fossil-fuel emissions. Thur did not mention fossil fuels.
“What I would say in response to that question is that we recognize that the planet is changing dramatically,” he said during the news conference. “Our role within NOAA is to try to predict what’s going to occur in the future by documenting what’s occurring today,” he said. “There is a human role, as our administrator currently, Dr. Neil Jacobs, said during his congressional confirmation hearing, for humans in influencing those changes.”
Matthew Druckenmiller of the National Snow and Ice Data Center, another lead editor of the report, made no such equivocations.
“Let us start by first acknowledging that the warming of our planet driven by human greenhouse gas emissions into our atmosphere is amplified in the Arctic,” he said near the start of the news conference. “The Arctic continues to warm much faster than the globe overall, amplified by the loss of reflective sea ice and snow, causing more of the sun’s heat to penetrate into land and ocean.”
Druckenmiller also said the Trump administration did not interfere with drafting of the report.
“I can say that in producing the Arctic report card in 2025, we did not receive any political interference with our results,” he said.
https://alaskabeacon.com/2025/12/16/ecosystem-shifts-glacial-flooding-and-rusting-rivers-among-alaska-impacts-in-arctic-report/
…………………………………….
other reports
Orange rivers and melting glaciers: federal report shows rapid change in the Arctic
https://www.wbur.org/npr/nx-s1-5639224/arctic-climate-change-noaa-report
https://www.npr.org/2025/12/19/nx-s1-5648270/trump-weather-climate-national-center-atmospheric-research-ncar
https://www.wypr.org/2025-12-19/scientists-push-back-on-trump-plan-to-break-up-a-critical-climate-and-weather-center
https://edition.cnn.com/2025/12/17/climate/ncar-trump-climate-research-weather-safety-forecasts
But some saw NCAR’s dismantling as a reason to leave the US. Space physicist Alexandros Chasapis is planning to move back to France to continue his research.
“The fact that this is on the table on its own is causing damage,” he said of closing NCAR. “Even if they walk this back tomorrow, you lose trust.”
What was clear to countless researchers at AGU is the scientific value of NCAR. “Every scientist has benefited in some way from what NCAR does,” said Marc Alessi, a science fellow at the nonprofit Union of Concerned Scientists.
Bloomberg at AGU — $53 billion The minimum cost to reconstruct Gaza. Bloomberg remote sensing journalist Krishna Karra has used satellite data and a machine learning model to map destruction and population movements in Gaza, and he presented the work at AGU.
https://www.bloomberg.com/news/newsletters/2025-12-19/five-takeaways-from-the-world-s-biggest-earth-science-meeting?srnd=homepage-africa
and
Several scholars and cultural critics have voiced perspectives that align with the view that the current political climate—characterized by juvenile rhetoric and “pissy” plaque rewritings—is a reflection of a deeper, systemic cultural decay in the United States.
Historians and political scientists have increasingly identified parallels between 2025 America and the rise of European fascism: Ruth Ben-Ghiat (NYU) An expert on strongmen, she notes “striking” similarities between current political tactics and Mussolini’s 1920s laws that dismantled judicial independence and centralized power. She argues that Trump’s use of “ritual humiliation” and victimhood narratives conditions followers to see political opposition as “the enemy within”.
Daniel Ziblatt (Harvard): Author of How Democracies Die, he observes that the combination of false allegations and threats of retribution against opponents mirrors the tactics of 1930s European fascists.
Critics point to a broader “mindset maturity” issue and a culture of narcissism permeating the American public. Academic studies highlight “national collective narcissism,” where a belief in national exceptionalism—threatened by perceived outsiders—justifies authoritarian leadership and the disregard for democratic procedures.
Observers see the “violence” of the current moment manifesting both rhetorically and physically. As of October 2025, approximately one-third of Americans believe political violence may be necessary to “set the country on the right path”—a significant increase from previous years.
Fact-checking White House plaques targeting former US presidents
https://www.bbc.co.uk/news/articles/c8e9jexe5k8o
Following on from the above news reports, this comment brings together several recent sources, historical perspectives, and ideas I’ve been reading and thinking about over the past year, alongside my own reflections. I asked an AI tool to help review the draft for clarity and coherence. These are challenging times for science and institutions globally — though the U.S. currently appears to be a focal point.
Where to from here: Climate Science in an Age of Imperial Decline and Institutional Simplification
What we are witnessing in the U.S. is not simply a communications failure or a temporary political aberration, but a deeper structural breakdown. Joseph Tainter’s framework helps clarify this: societies under rising complexity eventually reach a point where returns on complexity turn negative. At that stage, dysfunction is no longer anomalous — it becomes emergent. What looks like juvenile political theater, historical rewriting, or performative outrage is better understood as a system that can no longer manage reality nor complexity, and is beginning to fragment.
This interpretation aligns with a broader “declinist” perspective. Alfred McCoy has long argued that the U.S. is following the familiar arc of late-stage empires, marked by imperial overstretch, a bloated security apparatus, and costly interventions that undermine domestic resilience. By his account, the early 2020s represented a critical inflection point. Similarly, historian Mike Duncan has suggested that the U.S. has passed its imperial zenith, with current political devolution echoing the late Roman Republic — where inequality, institutional capture by private interests, and erosion of civic norms led citizens to seek refuge in demagogues rather than governance.
Climate science is not peripheral to this decline; it sits directly in its path.
As institutions deteriorate, the capacity to observe, measure, and respond to physical reality becomes a political liability. In late 2025 this reached a critical point. The Department of Government Efficiency (DOGE), even after formally closing, effectively institutionalized a logic of “simplification” that translated into mass attrition across the federal workforce. By December, more than 200,000 civil servants had departed, including thousands from NASA and HHS. The loss was not merely numerical — it represented decades of accumulated institutional memory, tacit knowledge, and continuity of observation.
From a Tainter perspective, this is not reform but forced simplification: a deliberate reduction in the state’s ability to perceive and manage complex physical systems. Climate research becomes especially vulnerable under such conditions because it depends on long time-series, stable institutions, and trust in measurement rather than ideology.
Complicating matters further is a growing convergence across the political spectrum toward what some critics describe as “liberal authoritarianism.” The neoconservative logic that once justified torture, surveillance, and disinformation — treating dissent as intent to harm — has increasingly been adopted in softer form by parts of the liberal establishment. Nuance is replaced by moral sorting, and disagreement becomes evidence of bad faith. This dynamic further fractures the social fabric and leaves climate science trapped between denial on one side and performative consensus enforcement on the other.
In such an environment, inconvenient truths are not debated; they are sidelined. The erosion of climate science is therefore not just about censorship or funding cuts, but about a broader collapse in the legitimacy of reality-based reasoning itself.
So how does climate science survive — even after Trump?
Not by persuasion alone, and not by returning to business as usual. In the short to medium term, survival depends on routing around federal dysfunction: state-level support, university-based refuges for expertise, independent data archiving, and communication that emphasizes concrete, locally experienced consequences of lost observational capacity. Farmers understand degraded weather forecasts; coastal communities understand missing tide gauges.
Longer term, recovery requires rebuilding institutional resilience rather than assuming political normalization will fix the problem. Legal protections for scientific integrity, durable stewardship of observational data, and public communication that explains what is lost when institutions fail matter more than rebutting bad-faith rhetoric online.
The core issue is not misinformation alone, but institutional collapse. Climate science persists not because society is ready to hear it, but because physical reality continues to assert itself. The task now is to preserve the capacity to observe that reality until institutions — and civic culture — are capable of facing it again.
A good thoughtful article.
The Climate Paradox: Politics of the Possible vs. Science of the Necessary
by Paulo Magalhães December 15, 2025
https://globalgovernanceforum.org/climate-paradox-politics-possible-vs-science-necessary/
According to the UNEP Emissions Gap Report 2025, global emissions reached a record 57.7 GtCO₂e in 2024, an increase of 2.3% over the previous year, more than four times the average annual growth rate of the 2010s. On the current trajectory, the world is heading toward 2.5°C of warming, even assuming full compliance with Nationally Determined Contributions, which is far from guaranteed.
UNEP’s Global Cooling Watch 2025 further estimates that avoiding catastrophic outcomes would require removing roughly 10 billion tonnes of CO₂ annually, effectively creating the planet’s second-largest industry, after fossil fuels, financed by more than one trillion dollars per year. These reports quantify need but leave open essential questions: who will act, under what legal framework, and with what financing?
Recognizing that emissions must fall 42% by 2030 compared with 2019 is not a plan.
COP30: resistance without regression
For many, the mood at COP30 contrasted sharply with the sense of possibility that followed Brazilian President Lula da Silva’s electrifying 2022 speech at COP27, when Brazil’s candidacy to host COP30 was celebrated as a potential turning point. That moment suggested a decade after Paris could deliver a science-aligned breakthrough from the heart of the Amazon.
But political winds shifted. Climate denialism gained ground. The U.S. left the Paris Agreement and this year, for the first time, they were not present at a COP. A parallel “politicized science” emerged, distorting debate. In this context, Dubai’s COP28 (held in a petrostate) is now remembered for at least mentioning a “transition away from fossil fuels.” Belém’s COP30 could not even agree on that, and in terms of deforestation, the final text was nearly identical to that of COP29 in Baku. A feared collapse was avoided, but only by holding the line, not advancing it.
Breaking the vicious cycle
If politics is the art of the possible, it becomes art only when creativity expands what is possible. As Nelson Mandela reminded us: “Everything is impossible until it’s done.” After thirty years of incrementalism, with Paris targets at risk of collapse this decade, continuing the same strategies is no longer responsible.
Or rational?
I don’t see how humanity survives this. 3 C by 2050. 5 C by the end of the century! Someone help me out with this. Thoughts?
https://www.responsiblealpha.com/post/scientists-3-c-by-2050-5-c-by-2100
Those are incorrect claims from the German Physical Society (DPG) and the German Meteorological Society (DMG). They’re cherry-picking a small number of CMIP6 models that are known to overestimate warming, including warming up to 2025. If those models are too warm in 2025, then there’s good reason to think they’ll also be too warm for 2050. The observed warming trend, better observationally-constrained CMIP6 models, CMIP5 models, the IPCC, etc. instead show we’re on pace for ~2°C by 2045-2050, 3°C by 2075-2090 (2060 at the absolute earliest), and ~3.5°C by the end of the century.
Atomsk’s Sanakan says
23 Dec 2025 at 7:23 AM
Those are incorrect claims from the German Physical Society (DPG) and the German Meteorological Society (DMG). They’re cherry-picking a small number of CMIP6 models that are known to overestimate warming,
Data: You need to prove that allegation is true, science based, then show your work and that list of “cherry-picked CMIP6 models”
AS: including warming up to 2025.
Data: no one needs a model to see what the warming up to 2025 are. But if they were serious then the diferences between the models and the observation would be already clear.
AS :If those models are too warm in 2025, then there’s good reason to think they’ll also be too warm for 2050.
Data: Prove that is true, show your work and reference everything.
AS : The observed warming trend, better observationally-constrained CMIP6 models, CMIP5 models, the IPCC, etc. instead show we’re on pace for ~2°C by 2045-2050, 3°C by 2075-2090 (2060 at the absolute earliest), and ~3.5°C by the end of the century.
Data: Prove that is true, show your work and reference everything.
Emotionally charged incoherent troll dumps on a forum do not count as credible science. Forster etc aren’t scientifically valid nor support your claims. ~2°C by 2045-2050 is blatantly false and unfounded.
Peer-Review doesn’t confirm a paper’s analysis and findings are in fact correct Scattered paintballs of ‘claims’ on a wall isn’t coherent science, let alone valid evidence of anything. Please take your unsubstantiated rants and trolling somewhere else.
None your tripe addresses cogently addresses evidence I linked, sockpuppet account. Let folks know when you can actually manage that. I doubt you’ll ever be able to, since you couldn’t even manage answering basic questions you were asked.
Re: “~2°C by 2045-2050 is blatantly false and unfounded.“
Great illustration of how Data disinforms, along with their sockpuppet accounts Jim, Neurodivergent, etc. The link in the post they replied to already cited evidence on this, despite Data pretending otherwise and willfully ignoring the evidence cited. That debunks their pretense of caring about references and evidence.
The document in question used Paris Agreement targets. Warming for those targets is calculated using a 20-year mean to mitigate bias from outlier years. This puts us at ~1.4°C. Extrapolating recent observed warming of ~0.26°C/decade implies 2°C by 2045-2050, not near 3°C:
Using a slightly higher trend of ~0.28°C/decade for reasons gone over in that post, implies 1.5°C by around 2029/2030, 2°C by 2045-2050, 3°C by 2075-2090, and 4°C by 2105-2130. That’s in the range of other projections, observationally-constrained CMIP6 models, CMIP5 models, the IPCC, etc. It’s also less warming than 3°C by 2050 and 5°C by 2100:
None of this evidence would ever get through to a sockpuppet account like Data.
Reply to Atomsk’s Sanakan Jan 1
Observed warming trends and CMIP projections are scenario-dependent and highly uncertain beyond a few decades; top-of-atmosphere energy imbalance, feedbacks, and emission pathways make exact dates for 2–3°C or 4°C warming inherently approximate.
CMIP outputs are plausible pathways under defined assumptions, not precise predictions.
My Ref:
The primary purpose of these projections is to inform policymakers about the potential consequences of different emission pathways, highlighting the urgency of reducing greenhouse gas emissions. Therefore, any suggestion that CMIP outputs, the IPCC, or other frameworks are making a temperature prediction for 2050, 2100, or any specific future period is scientifically invalid; these models do not make such predictions.
https://www.realclimate.org/index.php/archives/2026/01/unforced-variations-jan-2026/#comment-843345
Addendum to Reply to Atomsk’s Sanakan Jan 1
https://www.realclimate.org/index.php/archives/2025/12/unforced-variations-dec-2025/#comment-843341
Here are the relevant references showing Reply to Atomsk’s Sanakan “claims” based upon his multiple false / as yet unproven/falsified CMIP assumptions.
Atomsk’s Sanakan says
23 Dec 2025 at 7:23 AM
Those are incorrect claims from the German Physical Society (DPG) and the German Meteorological Society (DMG). They’re cherry-picking a small number of CMIP6 models that are known to overestimate warming, including warming up to 2025. If those models are too warm in 2025, then there’s good reason to think they’ll also be too warm for 2050. The observed warming trend, better observationally-constrained CMIP6 models, CMIP5 models, the IPCC, etc. instead show we’re on pace for ~2°C by 2045-2050, 3°C by 2075-2090 (2060 at the absolute earliest), and ~3.5°C by the end of the century.
https://www.realclimate.org/index.php/archives/2025/12/unforced-variations-dec-2025/#comment-843058
Atomsk’s Sanakan “whole argument” is relying on his assertions about CMIP modelling output and their assumptions.
SEE my Reply > Data says
23 Dec 2025 at 11:41 PM
Atomsk’s Sanakan says
23 Dec 2025 at 7:23 AM
Those are incorrect claims from the German Physical Society (DPG) and the German Meteorological Society (DMG). They’re cherry-picking a small number of CMIP6 models that are known to overestimate warming,
Data: You need to prove that allegation is true, science based, then show your work and that list of “cherry-picked CMIP6 models”
AS: including warming up to 2025.
Data: no one needs a model to see what the warming up to 2025 are. But if they were serious then the diferences between the models and the observation would be already clear.
AS :If those models are too warm in 2025, then there’s good reason to think they’ll also be too warm for 2050.
Data: Prove that is true, show your work and reference everything.
AS : The observed warming trend, better observationally-constrained CMIP6 models, CMIP5 models, the IPCC, etc. instead show we’re on pace for ~2°C by 2045-2050, 3°C by 2075-2090 (2060 at the absolute earliest), and ~3.5°C by the end of the century.
Data: Prove that is true, show your work and reference everything.
Emotionally charged incoherent troll dumps on a forum do not count as credible science. Forster etc aren’t scientifically valid nor support your claims. ~2°C by 2045-2050 is blatantly false and unfounded.
Peer-Review doesn’t confirm a paper’s analysis and findings are in fact correct Scattered paintballs of ‘claims’ on a wall isn’t coherent science, let alone valid evidence of anything. Please take your unsubstantiated rants and trolling somewhere else.
https://www.realclimate.org/index.php/archives/2025/12/unforced-variations-dec-2025/#comment-843073
To date none of these questions or points have been properly addressed nor falsified by Atomsk’s Sanakan, or anyone else.
Your post contains no cited evidence nor does it address the evidence I cited, sockpuppet. So I’ll continue to go with peer-reviewed published evidence from climate researchers like Forster et al., while you contradict your other sockpuppet account in your desperate attempts to dodge evidence. You don’t know better than published experts and you never will. Stew about it.
Re: “Observed warming trends and CMIP projections are scenario-dependent and highly uncertain beyond a few decades; top-of-atmosphere energy imbalance, feedbacks, and emission pathways make exact dates for 2–3°C or 4°C warming inherently approximate.“
None of the scenarios get to 3°C by 2050, as you’d know if you actually read the material cited to you (ex:this from IPCC 2021 figure SPM.8). But it’s clear you dodge evidence, as you’ve done across your sockpuppet accounts. Moreover, what Chuck originally cited and asked about was itself a projection. So it’s special pleading if you complain when others cite projections in response to show Chuck’s cited projection does not align with observed warming, nor with any other plausible projection. Your bias and reflective contrarianism is showing.
Re: “Therefore, any suggestion that CMIP outputs, the IPCC, or other frameworks are making a temperature prediction for 2050, 2100, or any specific future period is scientifically invalid; these models do not make such predictions.“
I said: “That’s in the range of other projections“. You responded with “prediction“, not ‘projection’. In messing up on the ‘projection vs. prediction’ distinction, you debunked your own point. Troll less, Data/Neurodivergent/Jim/etc., and actually learn the basics of what you discuss.
– Chuck: “2+ 2 = 17.5. I don’t see how humanity survives this.”
– Atomsk: “This is incorrect. 2+2=4”
Multi-troll, having no problems with Chuck’s doomer claim, attacks instead Atomsk:
“You need to prove that allegation is true, science based, then show your work”
The onus of proof, my little Jimmy- is on the party that makes the more extreme, countering the scientific consensus claim. That party is called: “Chuck”
And no, Chuck’s link to …. some website that links …. NOT to a peer-review paper, but another website is NOT “a science-based” paradigm-changing proof.
Data, the German Physical Society must have used models with high to very high climate sensitivity. Because the IPCC RCP 8.5 worst case scenario is based on medium climate sensitivity and high emissions, if you read their reports, and it generates 3 degrees C by about 2060 at the earliest, so to get to 3 degrees by 2050 requires high climate sensitivity, assuming the same emissions level. But given the high emissions pathway is now unlikely due to a reducing rate of coal use, this also reinforces that high climate sensitivity would be required. And the high sensitivity climate models have problems easily googled and discussed on this website. So you are asking AS to prove something already proven, like night follows day.
If a model can’t predict the warming trend up until 2025 with at least reasonable accuracy then its unlikely to be able to predict temperatures beyond 2025, in the same way as if your car is unreliable its unlikely to suddenly spontaneously become reliable. Its self evident. It doesn’t need mathematical proof.
in Re to Nigelj, 24 Dec 2025 at 6:12 PM,
https://www.realclimate.org/index.php/archives/2025/12/unforced-variations-dec-2025/#comment-843097
Hallo Nigel,
according to page 5 of the pdf fulltext of the common DMG&DPG call
https://www.dpg-physik.de/veroeffentlichungen/publikationen/stellungnahmen-der-dpg/klima-energie/klimaaufruf/pix/dpg_klimaaufruf_vollversion.pdf ,
its authors rely in one of their warnings (that high climate sensitivity – about 5 K for atmospheric CO2 concentration doubling – is more likely than the lower limit of the considered range 2-5 K) on three sources listed as reference 11, namely:
a. Witkowski et al. (2024). Continuous sterane and phytane δ13C record reveals a substantial pCO2 decline since the mid-Miocene. Nature Communications, 15(1), 5192. https://doi.org/10.1038/s41467-024-47676-9
b. Goessling et al. (2024). Recent global temperature surge intensified by record-low planetary albedo. Science. https://doi.org/10.1126/science.adq7280
c. Hansen et al. (2023). Global warming in the pipeline. Oxford Open Climate Change, 3(1), kgad008. https://doi.org/10.1093/oxfclm/kgad008
As regards the graphic from page 3 of the report suggesting the possibility of 3 K warming till 2050, it seems to be produced by certain Mr. or Ms. Gehlen, who was, according to reference (IV), inspired by a certain climate activist and book author, named Marcus Wadsak,
https://www.linkedin.com/in/marcus-wadsak-272971272/ ,
namely by his LinkedIn post
https://www.linkedin.com/posts/marcus-wadsak-272971272_timetoactisnow-klimawandel-activity-7205858639495016448-A7q9/?originalSubdomain=de
and, according to this reference, used the data from Shakun et al
https://www.nature.com/articles/nature10915
and Marcott et al.
https://www.science.org/doi/10.1126/science.1228026
I have not checked if these references can be indeed construed the way presented in the graphic.
It is, however, remarkable that “further literature to the topic” includes, as item (VIII), also a publication by Zeller and Nikolov,
https://archive.is/o/D6jev/https://doi.org/10.3390/geomatics4030017
Also interestingly, the full list of references is only in the archive version cited by Atomsk’s
https://archive.is/D6jev
that comprises also active links to Shakun, Marcott and Nikolov as cited above, whereas although the pdf. version cited above is accessible from this “archive”, it comprises only references (I)-(V) and some links therefrom seem to be inactive / inaccessible. On the other hand, the reference (IV) in the pdf. version comprises also the source of Wadsak’s graphic
https://climateemergencydeclaration.org/wp-content/uploads/2018/09/DontMentionTheEmergency2018.pdf
that is absent in the reference (IV) from the “archive” version.
Greetings
Tomáš
Tomáš Kalisz @ 25 Dec 2025 at 6:32 PM
Thanks for that information. I didn’t read the footnotes.
Its clear the German Geophysical Society are making quite big bold claims of 3 degrees C by 2050 given their graphic in the link posted by AS. To get to 3 degrees c by 2050 would require quite a massive leap in the decadal rate. I think Piotr said it would need to get to 0.65 degrees per decade which sounds correct.
AS seemed to be suggesting they are using discredited climate models. I couldn’t find a specific reference to this in the link he posted. But I thought they must be using the climate models that run very hot. In hindsight perhaps they could also be relying on something else related to the links you posted, but I doubt its James Hansen. He is predicting something like 0.45 degrees c per decade over the next couple of decades, which is way less than 0.65 degrees.
Its possible the GGS are just extrapolating the trend slope over the last 3 years which would be pretty stupid. Or perhaps they are relying on another source in one of the links you posted. I haven’t read all those. Its just a bit much to wade through and one paper is paywalled. And I’m already personally satisfied the GGS claim of 3 degrees by 2050 doesn’t sound credible, partly because its so much higher than the IPCC or even Hansen.
I do personally think climate change most likely accelerated around 2015 and this acceleration will likely significantly accelerate further, and that we are looking at future warming somewhere between what people like Mann and Hansen are predicting. This mainstream prediction is quite concerning enough without bothering about whether the extremists and speculators say, especially when like the GGS, they don’t bother to clearly state in their report how they arrived at 2 – 3 degrees by 2050. For all I know its from a science fiction novel.
But I do respect what Hansen says. He does back his claims with various suggested mechanisms and evidence although I lean a bit more towards the IPCC estimates.
The Three Musketeers?
Concern Trolling with nothing to say that’s relevant, no Data to contribute, or anything scientific.
They’ll keep.
Knock it off. I’m not trolling. I’m looking for either verification or an explanation. And I’m not a sock puppet account, as someone suggested.
I’m not a regular poster these days, but what I posted here did get some great explanations, which I am reading now.
I’m not a scientist but I do occasionally have questions. Relax.
Chuck: I agree the obsession with labeling people is wasteful and often inappropriate. That’s not to say that these entities don’t exist, but using them to insult people here has taken over the conversation in a way which is often nasty and wrong.
However, as noted, 3C is projected (possible, even likely) by 2100, not 2050. I don’t know where you got that figure. Surviving it is problematic at best, but it’s not happening in 14 years.
Oops, 24 not 14 years (2050 – 2026). My bad.
Susan to Chuck: “I agree the obsession with labeling people is wasteful and often inappropriate.
Except nobody “labelled” Chuck with anything. Nobody called _him_ “sock puppet account”, it’s the sock-puppet account that was called a “sock-pocket account”.
And to identify him as such, based on the 100s of earlier posts under various made-up name is calling “spade a spade”, if anything – a public service saving people here time on treating new sockpuppet handles as if they represented a new, open to arguments, person.
So your “labeling people is wrong” reply is misdirected – applies to the sock puppet account who resorts to labelling people as an unwitting admission of being incapable of disproving opponents arguments,
As for “Chuck” – by his fruits we shall know him. So far does not look good: he dramatically questions the future of humanity based on …. non-credible extreme numbers, and when these numbers are challenged, Chuck throws his original argument under the bus:
=========
Chuck: “ Knock it off. I’m not trolling. I’m looking for either verification or an explanation ”
Me: Sure, your:
Chuck: “ I don’t see how humanity survives this 3 C by 2050. 5 C by the end of the century!”
certainly sounds like … just a question by somebody who has no opinion on the matter.
And ended with the exclamation mark – that universal signal of a doubt … ;-)
================
To clarify: I’m not saying you’re trolling or a sockpuppet account. I’m saying Data and Jim are sockpuppets of Neurodivergent. You’re clearly not one of their accounts.
No doubt those 2 sockpuppets will soon leave, to be replaced by at least 1 new sockpuppet that posts with the same high frequency, posting style, idolization of Dr. James Hansen, failed criticism of the climate science community outside of James Hansen (ex: the IPCC), whining about ‘net zero by 2050’ not being enough, and so on. After all, they’ve been doing that for years across several rounds of sockpuppet accounts. The rest of us at least have the integrity to stick to the same account instead of using multiple accounts to spam, pretend others agree with us, bravely run from questions, etc.
Piotr, chill out. C’mon, enough. Make your point calmly.
– Chuck: “I don’t see how humanity survives this 3 C by 2050. 5 C by the end of the century!”
– Piotr: ” the current warming rate is below 0.3C per decade, not 0.64C.”
– Chuck: “And I’m not a sock puppet account, as someone suggested.”
– Piotr: “Nobody suggested _that._”
– Ron R.: ” Piotr, chill out. C’mon, enough. Make your point calmly.
=====
Good one, Ron! I didn’t know you are into deadpan. ;-)
Piotr: By writing a lengthy complaint which reveals you misread the meaning of what I wrote, you diminish your effectiveness. I keep my posts short for a reason. You left out this: “That’s not to say that these entities don’t exist, but using them to insult people here has taken over the conversation in a way which is often nasty and wrong.” On the whole, I trust you on science. It’s the insults which undermine your point(s).
I suggest you spend less time here. Find something local to do which helps more than extensive writing here, no matter how accurate.
Susan Anderson 29 Dec “ On the whole, I trust you on science. It’s the insults which undermine your point(s).”
What insults? Neither I nor Atomsk used ANY insults toward Chuck – NOBODY dismissed Chuck by insulting him as “troll”, and Nobody called _him _ “sock puppet account”.
You jumped in with your support for Chuck, without BOTHERING to check whether his claims were true, And your response:
S: “ I agree the obsession with labeling people is wasteful and often inappropriate.”
sounds much more like you agreeing with …. you – Chuck said NOTHING about “obsession” – nor wasn’t he protesting ineffectiveness of it.
And when I pointed that Chuck mistook to him what was clearly addressed to the Multi-troll – you …. glossed over these facts, and used my proving my points with quotes to …. dismiss my post as “lengthy complaint “, and lectured me of misreading/ignoring? your real message:
Susan: “You left out this: “That’s not to say that these entities don’t exist, but using them to insult people here has taken over the conversation in a way which is often nasty and wrong.”
I misread/ignored nothing, quite the contrary – I have directly challenged it:
====
P: “to identify [sock-puppet as sock-puppet] based on the 100s of earlier posts is calling “spade a spade”, if anything – a public service saving people here time on treating new sockpuppet handles as if they represented a new, open to arguments, person.”
====
And I stand by it – life is too short to not call spade a spade. It SAVES time when we identify the new handle as the old sock-puppet, and when Atomsk. MARodger, BPL or me answer puppet’s specific claim – that’s not for the multitroll’s edification, but for the benefit of a non-scientist, as an immunization against similar claims repeated elsewhere.
As for your advise, “I suggest you spend less time here.” coming at the end of
a disappointing for me post (I believe you are better than it), we clearly don’t see eye to eye on that. So I suggest you do you, and I’ll do me.
in Re to Atomsk’s Sanakan, 23 Dec 2025 at 7:23 AM,
https://www.realclimate.org/index.php/archives/2025/12/unforced-variations-dec-2025/#comment-843058
Dear Atomsk’s,
Thank you very much for your reference.
The problem I see not only with James Hansen, DPG, DMG but also with other scientists who try to somehow alarm the public with respect to the present climate change – irrespective whether it is about a stronger or weaker “climate emergency” or, in some cases, about alleged lack thereof – is the circumstance that many of them seem to genuinely believe they are right and their opponents are wrong.
My former boss told me once that “patent attorney should not be inventive”. In other words, if the attorney tries to somehow improve or further develop the concept presented by an inventor by his or her own ideas, there arises a risk that the contribution may be, finally, rather harmful than favourable for the client. I am afraid that a scientist who becomes so strongly convinced about his or her truth that (s)he is willing to present his or her view(s) as the “right” science in public campaigns may be, in fact, still wrong. I am afraid that such scientists may, step-by-step, lose their ability to perceive hints that are contrary to their view(s), and thus progressively suffer from a self-strengthening confirmation bias.
As a member of the public who necessarily hears the loudest voices only, I am afraid that under the described circumstance when all these mutually contradictory views present themselves as a scientific truth, I tend to assess all of them with a deep scepticism, as potentially biased.
Anyway, I think that it may be better to live in an uncertainty than in a false certainty. Therefore, I would like to appreciate not only your efforts but also all critical analyses provided by the moderators and other commenters.
I wish you merry Christmas!
Greetings from Zlín, Czech Republic
Tomáš
“Anyway, I think that it may be better to live in an uncertainty than in a false certainty”
i think it might not be a popular sentiment around here, and I apologize in advance to them, but not always. You ever heard of the term, “ignorance is bliss”. If you could choose to be happy or to know everything which would you choose? I know which I’d choose in a heartbeat (though it might be why we in the world have the problems we do).
True, some are happy and knowledgable but true happiness is a very rare gem.
https://usdictionary.com/idioms/ignorance-is-bliss/
in Re to Ron R., 27 Dec 2025 at 10:37 PM,
https://www.realclimate.org/index.php/archives/2025/12/unforced-variations-dec-2025/#comment-843176
Hallo Ron,
To be honest, I do not believe that any human being can know everything. That is why I cannot answer your question; I simply cannot imagine that such a choice could be available. Should someone offer this choice to me, I would have, very likely, hardly trusted that it is a serious offer.
What makes a sense to me is a slight modification to this offer which may better fit the practical life. I am afraid that curiosity may act as a kind of a drug. If I seek an answer to a question, I tend to sacrifice lot of things that are usually linked to happiness, simply because I would have not been happy if I knew that I stopped asking before I tried everything in my power.
In my case, the disadvantage of this addiction is that with increasing age, my list of unresolved questions that I had to put on ice becomes longer and longer anyway, despite of the invested effort.
Greetings
Tomáš
Tomáš, yeah. They say the more you know the more your realize that you don’t know. :/
It won’t be 3C by 2050 because the planet isn’t warming at 1C per decade but at o.2C which means by 2050 it would have warmed another 0.5C maximum making 1’95C which isn’t great. Even if CC has accelerated to 0.25C then it’s 0.6C per in 25 years.
Seems about right. We’re currently at ~1.4°C for the Paris Agreement’s longer-term level (the long-term trend, not the annual anomaly). And we’re warming at ~0.26°C/decade:
At around that rate we’re on pace to reach the Paris Agreement’s 1.5°C longer-term level by about 2029/2030, 2°C by 2045-2050, and 3°C by 2075-2090:
That’s in the range of other projections:
Pete,
keep in mind the 2024 record high (Fig. 1) in the GISS (Goddard Institute for Space Studies) analysis.
based on Hansen – https://www.giss.nasa.gov/pubs/abs/ha00510u.html
and Lenssen Schmidt – https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023JD040179
specifically see the Fig 1 graph to be found top of page on
https://jimehansen.substack.com/p/global-temperature-in-2025-2026-2027
Which shows 1970-2010 0.18 C and 2010 to present (2025) a linear fit of 0.31 C per decade
Hansen’s reasoning is to found in various commentary articles.
and then there is Rahmstorf Foster https://tamino.wordpress.com/2025/05/28/how-fast-is-the-world-warming/
We mentioned extrapolating the final rate estimate into the future (albeit only a few years), and that it is conceivable it might continue accelerating. Some think this was ill-advised, given that the central estimate for the most recent rate according to the given analyses is about 0.4°C/decade, quite a bit higher than expected and higher than most people believe.
using the Berkeley data and
The given analyses estimate the rate at about 0.043 ± 0.01 °C/year (0.43 ± 0.1 °C/decade), and those are sound computations but they are predicated on the assumption (or should I say “presumption”) that the signal follows our model exactly. …. When it comes to statistical models, no matter how useful they might be, George Box was right: they’re all wrong.
and
There’s a lot of good reason to believe that the rate isn’t as high as 0.4°C/decade. For my best estimate, I’ll say the rate is 0.33 -.1 +.2 °C/decade (i.e between 0.23 and 0.53, best guess 0.33).
If I could put words into Stefan and Grant’s mouths, is appears to me they do not believe it will be less than 0.30 C per decade warming in the near future.
As good as if not better than any other persons guess. Of course this is only statistics, and statistics are not reality. He’s right, it just “guessing”. All things being “equal” though 0.2C or less seems improbable now.
0.3C per decade warming, without any further acceleration (which cannot be ruled out scientifically) places the increase in warming from + 1.5C average the last 3 years (Hansen + multiple sources) to an 1880-1920 GISS Anomaly of +2.25 C by 2050.
Given the high degree of Unknowns though, I think it’s rash to completely rule out closer to +3.0 C anomaly by 2050 as anything could happen going forward we cannot safely predict. No one predicted the 2023-2024 rapid acceleration either. .
Whereas breaching 2C before 2040 is imminently plausible now. The joint DMG/DPG call makes clear that things are urgent even if their projections are on the higher end of what’s probable.
Re: “0.3C per decade warming, without any further acceleration (which cannot be ruled out scientifically) places the increase in warming from + 1.5C average the last 3 years (Hansen + multiple sources) to an 1880-1920 GISS Anomaly of +2.25 C by 2050.“
Nope, sockpuppet account. The document in question used Paris Agreement targets. Warming relative to the pre-industrial baseline of 1850-1900 for the Paris Agreement is calculated using a 20-year mean to mitigate bias from outlier years (i.e. what you’re exploiting). That puts us at ~1.4°C, not yet 1.5°C:
So ~1.4°C combined with 0.3°C/decade would mean the Paris Agreement’s 2°C threshold would be crossed around 2045. That’s consistent with what I said elsewhere and not near 3°C by 2050. Yet your sockpuppet account ‘Data’ baselessly claimed that: “~2°C by 2045-2050 is blatantly false and unfounded..” So you should talk with yourself to reconcile that difference with your sockpuppet; your eagerness to disagree and troll caused you to contradict yourself.
Re: “Given the high degree of Unknowns though, I think it’s rash to completely rule out closer to +3.0 C anomaly by 2050 as anything could happen going forward we cannot safely predict. No one predicted the 2023-2024 rapid acceleration either.“
The predictability of a longer-term trend exceeds that of a shorter term fluctuation. Hence why it’s easier to accurately predict a 1-to-1 ratio of heads-to-tails for 200 coin flips than for 10 coin flips.
Re: “The joint DMG/DPG call makes clear that things are urgent even if their projections are on the higher end of what’s probable.“
3°C by 2050 is not on the higher end of what’s probable. It’s not even probable; it’s extremely unlikely and undermined by evidence cited previously, such as cherry-picking models that overestimated warming through 2025. Wanting to urgently call people to action is not an excuse for promoting extremely unlikely scenarios without making it clear to the audience that they’re extremely unlikely. And yes, ‘extremely unlikely‘ is an appropriate term here, maybe even ‘exceptionally unlikely’. It’s ‘extremely likely’ and maybe even ‘virtually certain’ that 3°C won’t happen by 2050. That’s consistent with IPCC terminology and the uncertainty ranges for the IPCC’s projections:
It would be like if I told people it’s possible their plane flight explodes, without telling them how extremely unlikely that is. That would lead some people to behave like Chuck, saying: ‘I don’t see how plane passengers survive this! Someone help me out with this. Thoughts?‘.
Chuck says 20 Dec 2025 at 7:56 PM
I don’t see how humanity survives this. 3 C by 2050. 5 C by the end of the century! Someone help me out with this. Thoughts?
You are right to be alarmed questioning how humanity survives that kind of world. The goal of the article I suspect.
First their comment “global warming could reach 3°C above pre-industrial levels by about 2050” is using the upper bound of the calculations provided by the DPG/DMG German article.
https://www.dmg-ev.de/wp-content/uploads/2025/09/dpg-pm-xx_Klimaaufruf_pressemitteilung.pdf
Keep in mind the Mid-Century period (20-year averages covering roughly 2041–2060) on current SSP trajectories of SSP2-4.5 (Intermediate) and SSP3-7.0 (High GHG) the IPCC AR6 also gives broader warming ranges with the upper bounds of +2.5C to +2.6C respectively.
This implies that by around 2050, the multi-decadal average warming relative to 1850–1900 could lie somewhere in ~1.2 °C–3.0 °C (max @ SSP5-8.5), depending on how emissions evolve. These kinds of numbers are not definitive but estimated predictive ranges. The DPG/DMG as well uses projections out to 2050. They are not directly comparable.
A useful distinction here is between what AR6 actually showed and what this DPG/DMG statement is doing with recent observations. In AR6, the upper end of SSP5-8.5 already reached a potential ~3 °C in the 2042–2060 window, so a mid-century 3 °C outcome is not new within that scenario.
However, current global emissions are not tracking SSP5-8.5, and AR6 treated that pathway as a high-end stress test rather than a likely trajectory. The DPG/DMG statement instead extrapolates from recent observed warming, which necessarily includes short-term variability (ENSO, aerosol changes, ocean heat uptake), on top of the forced trend.
That makes the claim observationally motivated but not equivalent to being “on an SSP5-8.5 pathway”, and it does not resolve how much of the recent acceleration reflects transient natural or semi-forced factors versus a sustained long-term rate. Keeping that distinction explicit matters for interpretation.
Furthermore, the DPG/DMG statement itself is a call to policy makers for action. Of course they are emphasising the worst case top-end scenarios here. Which the Responsible Alpha journalistic article expands upon. Unfortunately they are not asking for anything new as far as action to solve the problem.
While it is still early days, to me this is another example of extrapolating the recent unexpected and not predicted 2010-2025 warming acceleration into the future. Will this acceleration rate be sustained? A good reason to keep one eye on what Hansen et al are suggesting is the underlying physics here.
My thoughts are we’ll have to wait for a while longer.
Re: “Keep in mind the Mid-Century period (20-year averages covering roughly 2041–2060) on current SSP trajectories of SSP2-4.5 (Intermediate) and SSP3-7.0 (High GHG) the IPCC AR6 also gives broader warming ranges with the upper bounds of +2.5C to +2.6C respectively.
This implies that by around 2050, the multi-decadal average warming relative to 1850–1900 could lie somewhere in ~1.2 °C–3.0 °C (max @ SSP5-8.5), depending on how emissions evolve.“
None of the IPCC’s warming scenarios reach 3°C by 2050, sockpuppet account; they’re all less than 3°C. That’s shown, for example, in this from figure SPM.8.
Re: “The DPG/DMG statement instead extrapolates from recent observed warming, which necessarily includes short-term variability (ENSO, aerosol changes, ocean heat uptake), on top of the forced trend.“
Extrapolating recent observed warming of ~0.26°C/decade would give 2°C by 2045-2050, consistent with observationally-constrained CMIP6 models, CMIP5 models, the IPCC, etc.:
So it’s not 3°C by 2050. 3°C by 2050 instead comes from cherry-picking a small number of CMIP6 models that are known to overestimate warming, including warming up to 2025.
Re: “While it is still early days, to me this is another example of extrapolating the recent unexpected and not predicted 2010-2025 warming acceleration into the future. Will this acceleration rate be sustained?“
1) You haven’t shown statistically significant acceleration of global surface warming. That’s because there’s not statistically significant acceleration yet.
2) Acceleration was expected, despite not enough time passing for it to be statistically detectable at a predetermined threshold for statistical significance.
Again, none of this is being said for your benefit, since you’re a lost cause. It’s instead for those you’re trying to disinform.
in Re to Atomsk’s Sanakan, 25 Dec 2025 at 11:36 AM,
https://www.realclimate.org/index.php/archives/2025/12/unforced-variations-dec-2025/#comment-843119
Hallo Atomsk’s,
In my recent reply to Nigel
https://www.realclimate.org/index.php/archives/2025/12/unforced-variations-dec-2025/#comment-843129 ,
I tried to show that the most alarming graphic on page 3 of the common call of the German Physical and Meteorological Societies seems to have a somewhat dubious origin. I have a plea to you:
If you have an access to primary sources that allegedly comprise the data forming (at least according to the reference (IV)) the basis for this alarming graphic, could you perhaps check if their interpretation in this strange graphic allegedly produced by certain Mr. or Ms. Gehlen (who is absent in the list of the authors at the end of the call) is correct?
To be honest, even though the equilibrium climate sensitivity were as high as 5 K for doubling of atmospheric CO2 concentration (as the authors of the common call are willing to accept), I still do not understand how this level of warming could be achieved already about the year 2100, as suggested by the said graphic.
Many thanks in advance for a comment and best regards
Tomáš
There’s not going to be an accurate figure/diagram that gets you to 3°C by 2050. I think you’re referring to the graph on page 3 of this. An accurate counterpart to that would be figure 1 of Kaufman 2022. But all the projections in that figure are below 3°C by 2050, similar to this from IPCC figure SPM.8. So again, what seems to have happened is people got 3°C by 2050 by cherry-picking a small number of CMIP6 models that are known to overestimate warming, including warming up to 2025.
in Re to Atomsk’s Sanakan, 27 Dec 2025 at 6:39 PM,
https://www.realclimate.org/index.php/archives/2025/12/unforced-variations-dec-2025/#comment-843169
Dear Atomsk’s,
In my reply to Nigel, I tried to show that
(i) the references in the common GPS/GMS call do not seem to refer to any specific set of CMIP6 models,
(ii) the most alarming graphic on page 3 seems to be inconsistent even with other statements of this call,
(iii) there seem to be discrepancies even between the text of the common call
https://www.dpg-physik.de/veroeffentlichungen/publikationen/stellungnahmen-der-dpg/klima-energie/klimaaufruf/stellungnahme
as published on the official DPG page and its pdf version you are referring to.
All these circumstances suggest that, unfortunately, both respectable scientific societies have not invested the necessary effort into editing the call thoroughly enough.
I am afraid that the editors simply failed in avoiding mutually conflicting and potentially misleading information. Personally, I really regret that two important societies representing German science demonstrated such a deficit of accuracy and thoroughness that have been traditionally considered as German virtues.
Greetings
Tomáš
Chuck 20 Dec: “ I don’t see how humanity survives this. 3 C by 2050. 5 C by the end of the century! Someone help me out with this. Thoughts?”
Garbage in (Chuck’s +0.64C per decade), garbage out: (Multitroll: “You are right “) ?
Reply to Piotr
Intentional quote surgery normally requires anaesthetic. That is not what I wrote, nor what I meant.
Re Data’s 27 Dec insinuations
Put your money where your mouth is, Buttercup, i.e., show how in your response to Chuck:
====
– Chuck: “ I don’t see how humanity survives this. 3 C by 2050. 5 C by the end of the century! ”
– “Data”: ” You are right [to be alarmed questioning how humanity survives that kind of world]”
===============================
by “ that kind of world ” you …. did NOT mean Chuck’s “ 3 C by 2050. 5 C by the end of the century!“, but apparently some …. completely different kind of world (D: “ not what I wrote, nor what I meant. “)
Until then:
– Now stand aside!
– Data: Tis but a scratch!
– A scratch? Your arm’s off!
– Data: No, it isn’t. [Then, seeing his arm gone] I’ve had worse.
This is interesting: “My 2026 and 2027 global temperature forecasts. The best thing about predicting the near future is you don’t need to wait long to be wrong Zeke Hausfather Dec 21, 2025.” Refer:
https://www.theclimatebrink.com/p/my-2026-and-2027-global-temperature
It relates to Regarding “Data says 18 Dec 2025 at 9:31 PM on Hansens warming predictions for 2026 – 2027.
I haven’t read all this material in detail, and I have no idea yet who might be making the best predictions, and I avoid taking sides too much. I’m posting this ONLY because its relevant not to necessarily promote ZH.
I do instinctively find Hansen quite impressive in a general sense. He is a visionary and he considers the big picture very well. Not everyone has that talent. And I know I have provably good instincts. But I also know instincts can be WRONG, so I maintain a healthy scepticism of anything anyone says including Hansen. Otherwise you end up with out of control hero worship like Taylor Swifts “swifties” . Good grief I don’t want to end up like that.
Nigelj,
That’s an interesting post by Zeke Hausfather – ‘My 2026 and 2027 global temperature forecasts’.
I note that he plots a 2025 annual average while using “the prior year’s temperature, the latest monthly temperature” in his methods. Both 2025 and Dec2025 still have a few days to go.
The ERA5 numbers at Climate Pulse are showing Dec2025 to-date (+1.40°C) with a far lower anomaly than Sept-Nov2025 (+1.52°C). Using this 1850-1900 anomaly base, Dec2025 to-date is sitting higher than Jun-Aug2025 (+1.28°C), although not with the 1991-2020 base (Jun-Aug +0.47°C, Sept-Nov +0.69°C, Dec to-date +0.47°C).
The annual ERA5 SAT averages thus would run 2023 +1.48°C, 2024 +1.60°C, 2025 +1.47°C.
Mind, Zeke Hausfather isn’t using SAT (which is a bit more ‘acceleraty’ than the SAT/SST records.
The annual SAT/SST averages he plots run 2023 +1.46°C, 2024 +1.55°C, 2025 +1.44°C.
And just to add to the confusion, GISTEMP used by Hansen (SAT/SST) averages 2023 +1.45°C, 2024 +1.56°C, 2025-to-Nov +1.47°C. The full year GISTEMP 2025 will likely end up +1.46°C.
The various predictions (each given with large confidence intervals not shown by me) as reported by Hausfather, run for 2026 (& 2027 in brackets):-
Hansen….. … …. +1.47°C (+1.70°C)
Hausfather……… +1.41°C (+1.57°C)
UK Met Office… +1.46°C
I don’t actually see this 2026 =. +1.47°C quoted by Hausfather in Hansen’s ‘Global Temperature in 2025, 2026, 2027’ so I assume it is a mis-quote.
Hansen’s suggestion that the 12-month rolling temp will drop at some point due to the next La Niña to +1.4°C (previously sort-of implied back in March) before rising to the new record for 2027. That +1.4°C La Niña dip may then fit with the Hausfather’s 2026=+1.41°C although perhaps the 12-month rolling averages may drop further. The last seven months Apr-Nov25 actually average +1.40°C and what with the strange Sept-Nov warm SH wobble over and the autumn warm NH wobble looking rather muted, the next few months may dip down below +1.4°C.
MA Rodger says
“I don’t actually see this 2026 =. +1.47°C quoted by Hausfather in Hansen’s ‘Global Temperature in 2025, 2026, 2027’ so I assume it is a mis-quote.”
And nigelj ” you don’t need to wait long to be wrong”
–
Quoting Zeke:
“Not to be outdone, James Hansen released his estimate that 2026 temperatures will also be around 1.47C in the GISTEMP dataset (albeit using a somewhat different 1880-1920 baseline)3, with the 12 month average dipping down to around 1.4C in the coming months before rising back up by year’s end.”
https://www.theclimatebrink.com/p/my-2026-and-2027-global-temperature
I don’t think this is likely to be a “misquote” by Zeke so much as a reading or interpretation issue.
In the Hansen et al. paper, there is no explicit global temperature prediction for 2026. The +1.47 °C figure refers specifically to 2025:
“Global temperature of +1.47 °C in 2025 relative to 1880–1920 is the 2nd highest in the period of instrumental data …”
Hansen et al. then note that:
“The 12-month running-mean temperature should decline for the next few months, reaching a minimum about +1.4 °C.”
https://jimehansen.substack.com/p/global-temperature-in-2025-2026-2027
Zeke’s phrasing (“2026 temperatures will also be around 1.47 °C”) appears to be an extrapolative paraphrase rather than a value stated by Hansen et al. Direct quotation seems the safer and clearer approach here.
Addendum (clarification)
Hansen et al. distinguish carefully between calendar-year global mean temperature anomalies and the 12-month running mean. The +1.47 °C value refers to the 2025 annual mean. The subsequent statement that temperatures “should decline for the next few months, reaching a minimum about +1.4 °C” refers specifically to the evolution of the 12-month running mean, not to an annual average for a future year.
Describing this as a “12-month average” or associating it with a specific calendar year risks conflating these two distinct quantities.
Nigelj says
22 Dec 2025 at 2:46 PM
I haven’t read all this material in detail, and I have no idea yet who might be making the best predictions, and I avoid taking sides too much. …………… Otherwise you end up with out of control hero worship like Taylor Swifts “swifties” . Good grief I don’t want to end up like that.
You know, everyone can see what you say.
Thanks Nigel.
ZH, “The best thing about predicting the near future is you don’t need to wait long to be wrong”
Refreshing. In this narcissistic world to be humble enough to admit one’s own imperfections is quite rare. More of that.
https://midmiocene.wordpress.com/2015/12/31/resolutions/
Ron R. says
23 Dec 2025 at 8:21 PM
Refreshing.
It is quite common. More common that you chaps seem to be aware of. The prevailing climate here isn’t real world. Spread your wings.
Ron R. Excellent. Thanks for the link.
Happy New Year all.
Ron, I have this question about “regrets”:
If you had never done any of those things you regret, who would you be?
(I mean, if you are going to reference Watts, you have to be prepared to encounter those kinds of profundities, right? ;-) )
I liked the video, especially the stars. I haven’t seen them in a long time; it’s actually the only thing I’ve got on my one-last-time list. Crawling out from a bag, standing in the snow peeing, looking up… pretty much covers what he was talking about.
Zebra, good question. Have to think about that for awhile. Not the current me, though. Of all the many paths I could have taken I would hope I’d have chosen a better path. Who wouldn’t? Be a better version of me. Might have saved myself a lot of anguish. But then I might not have learned as much. That last part might be what your driving at.
But then again, would I rather know or be happy?
Watts was an environmentalist. But he was also a Zen Buddhist. As far as I know, Zen Buddhism’s bottom line is that you have to discover the answers for yourself. You can correct me if I’m wrong, my friend.
Zebra, I muffed that up. You understand. I have more evolving to do. :/
Ron,
I will try to reply further next month. For me, it’s a very interesting topic; Watts wrote specifically on that “who am I?” trying to show the difference between “Eastern Thinking” and “Western Thinking”. And it all ties in with modern physics and even climate science.
Oh and you motivated me to check wiki-p on Watts; lots of interesting details I had no idea about. I just have this old paperback of his turning yellow on my bookshelf; you also motivated me to get it down after all these decades and check out the pages I had bookmarked.
Ron R. “Refreshing. In this narcissistic world to be humble enough to admit one’s own imperfections is quite rare”
You may be reading more into it than there is. ZK has admitted nothing, certainly not “his own imperfections”. He wouldn’t offer his prediction if he did NOT think that the odds of him being right are substantially higher than him being wrong. As such – this is neither a proof of any particularly “refreshing humbleness”, nor is as rare as you think it is.
What about Hansen et al “warming predictions” for 2026 – 2027?
First what of his 2025 “predictions”, they count now already. These suggest that Hansen’s “acid test” proved valid. And his “predictions” (couched in the unknown of how the typical 0.5C swing in natural variation of ENSO would unfold) have proven quite correct-if not at least they confirm his analysis is stronger now 2 years ago.
Global surface temperature averaged over 2025 will depend in part on how ENSO develops during 2025, but even if a La Nina reemerges, we expect 2025 global temperature to be at least +1.5°C relative to 1880-1920.
https://www.columbia.edu/~jeh1/mailings/2025/2025GlobalTemperature.15April2025.pdf
Showing an actual +1.47C anomaly, a drop of only 0.1C off the 2024 GMST (GISS) of 1.57c
Further back-
Two years ago (29 March 2024) we projected that global warming in the then-ongoing El Nino
would rise much more than in prior El Ninos, raising global temperature to at least +1.6°C, and
that temperature after the El Nino would fall only to +1.4°C (see Fig. 2).
https://www.columbia.edu/~jeh1/mailings/2025/GlobalTemperaturePrediction2025.12.18.pdf
Actual 2024 was 1.57C and after el nino this year 2025 is +1.47C and falling. Quite close given the constraints.
See-
Global temperature of +1.47°C in 2025 relative to 1880-1920 is the 2nd highest in the period of
instrumental data, about 0.1°C cooler than the 2024 record high (Fig. 1) in the GISS (Goddard
Institute for Space Studies) analysis.
https://www.columbia.edu/~jeh1/mailings/2025/GlobalTemperaturePrediction2025.12.18.pdf
Next for some more context see how Hansen et al differentiate their findings from others “predictions” eg Zeke H and many others.
IPCC’s approach to climate analysis came to be dominated by use of global climate
models (GCMs) for climate simulations of the past 1-2 centuries. We have taken a complementary
approach, placing comparable emphasis on paleoclimate data, GCM modeling, and modern
observations of climate processes, as described in our three main papers published in the past
decade: (1) “Ice melt, sea level rise and superstorms,”4 (2) “Global warming in the pipeline,”5 and
(3) “Global warming has accelerated.”6 The third of these, published last week, was long, as it tied
all three together, especially via its Supplementary Material (SM),7 which usually houses only
secondary material. Here is a link to the Abstract + Paper + SM as a single document. Below, we
first provide a plain language summary of the three principal conclusions of this paper and then
address questions raised in the media by kibitzers.
1. The leap of global temperature in 2023-2024 is explained; no new physics is required
2. Climate sensitivity is 50 percent larger than the best estimate of IPCC
https://www.columbia.edu/~jeh1/mailings/2025/Acceleration.12Feb2025.pdf
That article, need to be read in full and understood in context of those peer-reviewed papers,
See-
The question is: how much further is climate sensitivity altered by the cloud feedback? Let’s consider
three cases: (1) negligible cloud feedback, gcl ~ 0, (2) modest cloud feedback, gcl ~ 0.1, and large cloud
feedback, gcl ~ 0.25. These three cases yield equilibrium climate sensitivities of 2.4°C, 3°C and 4.8°C
(see equation 4), respectively. The observed change of Earth’s albedo during the past 25 years allows
unambiguous discrimination among these three cases: the large observed decrease of Earth’s albedo
rules out the zero and moderate cloud feedbacks. The cloud feedback is large, implying, with a high
degree of confidence, that real-world climate sensitivity is much higher than 3°C for doubled CO2.
https://www.columbia.edu/~jeh1/mailings/2025/CloudFeedback.13May2025.pdf
And again we see Hansen’s repeated accurate and scientifically valid “prediction” for 2025.
The Acid Test: Global Temperature in 2025
James Hansen and Pushker Kharecha 20 February 2025
An “acid” test of our interpretation will be provided by the 2025 global temperature:
unlike the 1997-98 and 2015-16 El Ninos, which were followed by global cooling of more than
0.3°C and 0.2°C, respectively, we expect global temperature in 2025 to remain near or above the
1.5°C level.
https://www.columbia.edu/~jeh1/mailings/2025/Acid.Test.20Feb2025.pdf
Best read in full and understood. The 2025 result is +1.47C – which is “near” the 1.5C level. This preliminary “acid test” has been passed. A drop on 2024 el nino of only 0.1C as opposed to the historical norm of 0.3C to 0.4C fall in GMST the following year / period due to ENSO. Goes to some confirmation of Hansen’s larger “theory” of what is happening now, and why.
This work and analysis by Hansen et al spanning 6 years now goes far beyond anything Zeke H has to say on global temp anomalies. Instincts have nothing to do with it. It’s good science and excellent reasoning. The 2025 temp results offer strong conditional support that Hansen’s analysis is correct. Being mindful that anything might happen with “so-called natural variation” in the meantime his 2026 and 2027 predictions offer the opportunity for further confirmation his theory is on solid scientific ground, once the Data is in.
See- Fig. 4. NCEP CFS.v2 Nino3.4 forecast (issued 15 December)4
Global warming projection. Assumption of at least a moderate El Nino beginning in 2026
leads us to the projection in Fig. 5, with global temperature reaching a minimum at or above
+1.4°C within several months and then rising to a record global temperature of about +1.7°C in
2027. This new record will occur only four years after the 2023 El Nino, so additional,
underlying, global warming at the accelerated rate of 0.31°C per decade is only about 0.1°C
https://www.columbia.edu/~jeh1/mailings/2025/GlobalTemperaturePrediction2025.12.18.pdf
Soooo… anyone notice that my 2015 #theory on #ElNino effects on #ASI is still intact, unbroken after ten years?
Reply to Killian
Sounds reasonably plausible. Pity a paper wasn’t published on it.
The other issue (I think you may have flagged too Killian) about global warming will “soon” show itself to be disrupting the ENSO pattern. The cycle is being disrupted now and this is clearly being observed. La Nina in particular is showing as being affected where decline in temps and other conditions are shifting. Time frames are contracting, ot at least appear so. In time this too will be undeniable. And change everything surrounding the “so-called natural variation” tool when things do not add up nor reflect the expected conditions based on models and typical consensus thinking.
My observation based opinion which I predict will eventually be reflected in the real science. I expect before 2030 there should be some papers out about this shift. Along with many more about albedo aerosols and cloud feedbacks and ongoing warming acceleration no matter what happens with ENSO or emissions here on in. Ideas first, the data will follow.
Started affecting ENSO in 1995. It started 1995. By 2012 the wind was a massive 30% (1 metre / second) stronger than pre-1995. I’ve not yet found post 2012 so I don’t know whether the big 2015/16 El Nino was the end of the massive 17 to 20 year Trade Wind surge. ENSO is an utterly-vast feature of Earth’s surface-air.
—————-
Quote: “Atlantic warming turbocharges Pacific trade winds Date: August 3, 2014 Source: University of New South Wales. New research has found rapid warming of the Atlantic Ocean, likely caused by global warming, has turbocharged Pacific Equatorial trade winds. Currently the winds are at a level never before seen on observed records, which extend back to the 1860s. The increase in these winds has caused eastern tropical Pacific cooling, amplified the Californian drought, accelerated sea level rise three times faster than the global average in the Western Pacific and has slowed the rise of global average surface temperatures since 2001. It may even be responsible for making El Nino events less common over the past decade due to its cooling impact on ocean surface temperatures in the eastern Pacific. “We were surprised to find the main cause of the Pacific climate trends of the past 20 years had its origin in the Atlantic Ocean,” said co-lead author Dr Shayne McGregor from the ARC Centre of Excellence for Climate System Science (ARCCSS) at the University of New South Wales.”
—————-
Quote: “The record-breaking increase in Pacific Equatorial trade winds over the past 20 years had, until now, baffled researchers. Originally, this trade wind intensification was considered to be a response to Pacific decadal variability. However, the strength of the winds was much more powerful than expected due to the changes in Pacific sea surface temperature. Another riddle was that previous research indicated that under global warming scenarios Pacific Equatorial Trade winds would slow down over the coming century. The solution was found in the rapid warming of the Atlantic Ocean basin, which has created unexpected pressure differences between the Atlantic and Pacific. This has produced wind anomalies that have given Pacific Equatorial trade winds an additional big push. “The rapid warming of the Atlantic Ocean created high pressure zones in the upper atmosphere over that basin and low pressure zones close to the surface of the ocean,” says Professor Axel Timmermann, co-lead and corresponding author from the University of Hawaii. “The rising air parcels, over the Atlantic eventually sink over the eastern tropical Pacific, thus creating higher surface pressure there. The enormous pressure see-saw with high pressure in the Pacific and low pressure in the Atlantic gave the Pacific trade winds an extra kick, amplifying their strength. It’s like giving a playground roundabout an extra push as it spins past.” Many climate models appear to have underestimated the magnitude of the coupling between the two ocean basins, which may explain why they struggled to produce the recent increase in Pacific Equatorial trade wind trends. While active, the stronger Equatorial trade winds have caused far greater overturning of ocean water in the West Pacific, pushing more atmospheric heat into the ocean, as shown by co-author and ARCCSS Chief Investigator Professor Matthew England earlier this year. This increased overturning appears to explain much of the recent slowdown in the rise of global average surface temperatures. Importantly, the researchers don’t expect the current pressure difference between the two ocean basins to last. When it does end, they expect to see some rapid changes, including a sudden acceleration of global average surface temperatures. “It will be difficult to predict when the Pacific cooling trend and its contribution to the global hiatus in surface temperatures will come to an end,” Professor England says.”
—————-
Recent intensification of wind-driven circulation in the Pacific and the ongoing warming hiatus
Nature Climate Change 4, 222–227 (2014) doi:10.1038/nclimate2106 Received 11 September 2013 Accepted 18 December 2013 Published online 09 February 2014 Corrected online 14 February 2014
Matthew H. England, Shayne McGregor, Paul Spence, Gerald A. Meehl, Axel Timmermann, Wenju Cai, Alex Sen Gupta, Michael J. McPhaden, Ariaan Purich & Agus Santoso
– Killian: ” Soooo… anyone notice that my 2015 #theory on #ElNino effects on #ASI is still intact, unbroken after ten years?”
– Data: “Pity a paper wasn’t published on it.”
Ouch. Et tu, Multi-troll, contra me? ;-)
Soooo …. why didn’t you publish it, Killian?
Reply to Data (re Killian’s comments)
There is a growing literature examining how ENSO behaviour may evolve as the background tropical Pacific warms, including potential changes in amplitude, duration, spatial structure, and mean state. Most of this work is based on modelling experiments rather than clear observational detection, and there is still no consensus that a distinct regime shift has yet emerged.
One important distinction is between a theory remaining internally consistent and the climate system entering a new, detectable regime. ENSO variability is now superimposed on a warmer baseline, which alters impacts even when the underlying oscillation remains recognisable. For example, weak La Niña events no longer produce the same global cooling as in past decades, simply because the background climate state has shifted.
Model results remain mixed. Some simulations suggest increased ENSO variability or extremes under warming; others show reduced variability, altered periodicity, or transitions toward El Niño–like or La Niña–like mean states under stronger forcing. These divergent outcomes largely reflect sensitivity to processes that remain poorly constrained, including fine-scale ocean mixing, stratification, air–sea coupling thresholds, and nonlinear feedbacks.
The key issue, therefore, is not whether familiar modes persist, but whether they continue to operate in the same way as the climate warms. At present, models are better suited to exploring plausible regimes and risk envelopes than to confirming specific outcomes or timelines. That argues for caution in treating continuity of past behaviour as confirmation, rather than as something that still needs to be tested against a changing background state.
For those interested in the current state of the science, there are several recent reviews and modelling studies exploring ENSO sensitivity to mean-state warming, nonlinear regime behaviour, and limits to detectability in the observational record.
Background warming and reduced La Niña cooling headroom (illustrative reporting):
https://www.livescience.com/planet-earth/weather/la-nina-is-dead-after-just-a-few-months-what-happened
ENSO signal detection and uncertainty under warming:
The impact of global warming on ENSO from the perspective of objective signals
https://www.sciencedirect.com/science/article/abs/pii/S0169809523005732
Emerging ENSO regime sensitivity in models:
Deep ocean warming–induced El Niño changes
https://www.nature.com/articles/s41467-024-50663-9
El Niño–like warming underestimated in a warmer climate due to ENSO rectification effect
https://www.nature.com/articles/s41612-025-01250-2
Nonlinear ENSO response across climate states:
Nonlinear sensitivity of the El Niño–Southern Oscillation across climate states
https://cp.copernicus.org/articles/21/1079/2025/cp-21-1079-2025.html
Jim, during the period ~1970-2014 oft cited as a trend of +0.180 degrees / decade the La Nina and ENSO-neutral years both had a pretty-obvious trend of +0.165 degrees / decade (with the ENSO-neutral being a warmer trend line of course and I recall 0.13 degrees warmer but don’t quote me)
with the slack taken up by El Nino years warming at +0.20 degrees / decade until 1995 and then at +0.23 degrees / decade 1995 to 2012 but it was spotty and I used calendar years (2 years per El Nino).
I made that plot on 11×17 paper in 2013 and intended to do it again using El Nino periods instead of calendar years. At https://www.youtube.com/watch?v=agKayS6h6xA 21:38 to 23:20 colour-coded pictorial of GMST anomaly 1976-98 to 1999-2012 and wind explanation.
The sun is now the highest it will get at Vostok Station, Antarctica. The record high ever recorded is apparently 6.8 F, but it is forecast to be 8 to 10 F in a day or 2.
https://en.wikipedia.org/wiki/Vostok_Station#Climate
https://www.timeanddate.com/weather/antarctica/vostok-station/ext
Up north, the interior of Alaska has had a decent cold spell for the past couple of weeks and it seems to be continuing:
https://www.timeanddate.com/weather/@5859415/ext
Mr. KIA. Thanks. It snowed here so I pushed snow until 22:30 because it’s scheduled to be concrete by this morning.
KiA – “ the interior of Alaska has had a decent cold spell for the past couple of weeks and it seems to be continuing”
And you are telling us this because ….?
We have explained to you the difference between local weather and global climate many times already, haven’t we?
Though the attack on NCAR/UCAR is ‘old news’ this is a valuable summary, including more detail about its international importance: Trump administration announces plans to ‘break up’ the National Center for Atmospheric Research. The center is one of the world’s premier institutions for studying the atmosphere. Its work has saved countless lives. https://yaleclimateconnections.org/2025/12/trump-administration-announces-plans-to-break-up-the-national-center-for-atmospheric-research/
“NCAR has been operated since its inception by the not-for-profit University Corporation for Atmospheric Research, or UCAR, through a cooperative agreement renewed through a competitive process and extensive review every five years. UCAR comprises 129 member institutions from across North America, all of which offer research and education programs in the atmospheric or related sciences. Along with carrying out administrative tasks for NCAR, UCAR manages a set of smaller programs that carry out education, training, field program support, and other activities related to the Earth and atmospheric sciences. Thousands of scientists from across the world are involved with NCAR and UCAR in myriad ways.”
Lots more at link …
—
The current article is also useful: Improving indoor air quality might save your life. Cost-effective ways exist to improve your indoor air quality that will reduce your COVID and flu risk, lower your cancer and lung disease risk, and eliminate headaches and sleepiness caused by poor ventilation. https://yaleclimateconnections.org/2025/12/improving-indoor-air-quality-might-save-your-life/
Thanks, Susan. It’s good to see such opposition.
I was a senior research software engineer in UCAR’s Unidata program for 35 years.
Needless to say, this Administration’s desire to dismantle NCAR is insane, IMO. To use a farming metaphor, it’s like eating one’s seed corn.
Gavin-san,
I looked up the GISS page on aerosol optical depth, and found that their time series ends in 2012. I was able to extend that to 2019 with Miller’s (2021) data. Is there any update through 2024?
[Response: Try this (via input4mips): https://aims2.llnl.gov/search?project=input4MIPs&versionType=all&activeFacets=%7B%22variable_id%22%3A%22sad%22%2C%22frequency%22%3A%22mon%22%2C%22grid_label%22%3A%22gnz%22%2C%22source_id%22%3A%22UOEXETER-CMIP-2-2-1%22%2C%22mip_era%22%3A%22CMIP7%22%7D – gavin]
Thanks!
Looking around recent output about 2026 estimates/predictions my thinking is essentially how the forecasting centres themselves would phrase it: Near-term central estimate for 2026 GMST: ~1.4–1.5 °C above a pre-industrial baseline (≈1850–1900; very close to 1880–1920 once adjusted).
Best current conservative midpoint: ~1.45 °C. The ENSO wildcard: is still unresolved for mid-/late-2026. If conditions remain neutral or La Niña-leaning, the year likely stays just under 1.5 °C. If a moderate El Niño unexpectedly emerges sooner, the same underlying forced signal would almost certainly push the annual mean over 1.5 °C again, as we’ve just seen in 2023-2025.
Crucially — and this is often missed in public framing I see — nothing dramatic needs to “change” physically for that to happen. It’s the same elevated baseline plus interannual variability riding on top. General analysis shows Hansen’s 2026-2027 predictions are plausible.
On CO₂, my instinct is also mirroring general analysis There’s no serious scenario in the mainstream energy / emissions outlooks (IEA, Global Carbon Project, NOAA trend extrapolations) that shows anything other than another record atmospheric CO₂ level in 2026. The uncertainty is rate of increase, not direction. Adding weight to a continued warming acceleration above recent decades.
Difference in any of these short term annual predictions are of little importance. It’s the longer term sustained trends that matter more. But people can’t help themselves so here we are, still “arguing debating” the drivers of the 2023-2025 acceleration on top of the 2010 to 2025 acceleration of warming. There is no agreement, there is no consensus still. Real Climate has still not concluded it’s initial questioning of why this happened. It appears to have no opinion what caused the spike in warming in 2023-2024.
Frankly, I’m not sure it matters anyway. Secondly, we often have fake pronouncements online like this anonymous one- claiming to accurately speak for climate institutions, while offering zero evidence or qualified references to support it.
Atomsk’s Sanakan says
23 Dec 2025 at 7:23 AM
The observed warming trend, better observationally-constrained CMIP6 models, CMIP5 models, the IPCC, etc. instead show we’re on pace for ~2°C by 2045-2050, 3°C by 2075-2090 (2060 at the absolute earliest), and ~3.5°C by the end of the century.
https://www.realclimate.org/index.php/archives/2025/12/unforced-variations-dec-2025/#comment-843058
Atomsk’s claim is nonsense This statement does not correspond to anything the IPCC or CMIP system publishes. There is no evidence, no data nor analysis provided to prove this is accurate, or even close. It’s not a valid interpretation — it’s fabrication by compression.
Any statement like “2°C by 2050” without an explicit SSP and averaging window is not an IPCC result. Neither CMIP5, CMIP6, nor AR6 state that we are “on pace” for 3°C by 2075. That framing collapses multiple scenarios, ignores averaging periods, and replaces assessed ranges with an unsupported point estimate.
This “claim” by Atomsk’s Sanakan is not in AR6, not in CMIP, and not in any IPCC table or figure. It’s a personal extrapolation rhetorically attributed to the IPCC. It’s standard fluff from anonymous contributors trying to sound sciency and authoritative when they are not
………………………………………………………
Please note the difference with what Hansen presents in his regular articles such as his latest here: https://jimehansen.substack.com/p/global-temperature-in-2025-2026-2027
Hansen is doing something quite different and this matters. Hansen’s recent work is explicitly outside the CMIP consensus frame. Key differences are:
He states physical mechanisms (aerosols, ocean heat uptake)
He makes falsifiable near-term predictions
He does not pretend CMIP means are observations
He separates scenario uncertainty from physics uncertainty
You can disagree with Hansen — but he is doing science, not rhetorical synthesis. While the “consensus” commentators are doing authority signaling, not scientific climate modelling. It’s useful to spot the difference.
Hansen is doing science, not rhetorical synthesis.
… pontificates Multitroll “Data”, who himself is doing no science, only empty rhetorics?
“While the “consensus” commentators are doing authority signaling not scientific climate modelling. ”
… and so we are on the same page – how many climate models have YOU designed?
And what’s that authority signaling you speak of – something like YOU trying to gain credibility by associating yourself with the authority of Hansen?
Missing a beam in your own eye, again?
You disingenuously left out the link to evidence cited in that post:
https://www.realclimate.org/index.php/archives/2025/11/unforced-variations-nov-2025/#comment-842463
Pretty typical of your disinformation tactics across your sockpuppet accounts. Hansen doesn’t need you to continue trying to mislead people to prop him up.
Re: “Atomsk’s claim is nonsense This statement does not correspond to anything the IPCC or CMIP system publishes. There is no evidence, no data nor analysis provided to prove this is accurate, or even close. It’s not a valid interpretation — it’s fabrication by compression.“
Nope since, for example, this was provided at the link the sockpuppet account willfully left out:
This is a further illustration of how the sockpuppet is deceptive across their accounts.
Chuck: “ Knock it off. I’m not trolling. I’m looking for either verification or an explanation ”
Sure, your:
“ I don’t see how humanity survives this 3 C by 2050. 5 C by the end of the century!”,
certainly sounds like … just a question by somebody who has no opinion on the matter.
Particularly the highlighted part.
And then the exclamation mark – that universal signal of a doubt … ;-)
Chuck: And I’m not a sock puppet account, as someone suggested.
Except no one suggested _that_. The sockpuppet is the multi-troll you may know from the last month or so as: “Data”, “Jim, “Mo Yunus”,”Neurodivergent”. “Miell”-backwards, “Jim Hansen”-backwards. And dozens? hundreds? of other names from the months and years before. .
So nobody said that you ARE the sock-puppet, but merely that you are being USED by one:
Sockpuppet “Data” first butters you up:
You are right to be alarmed questioning how humanity survives that kind of world”
– and then uses YOU as an implied ally in attacking his/her/its opponents:
Sockpuppet “Data”: First their comment [YOUR] “global warming could reach 3°C above pre-industrial levels by about 2050”
and follows with a long post, brimming with the supposed numbers, quotes, and sources – – all to HIDE the fact that he CAN’T prove YOU right: he can’t show the 0.64C per decade warming required to achieve YOUR: 3°C above pre-industrial levels by about 2050”.
The point of “flooding the zone” with his, ehem, material is that the opponents would be tied down disputing details, while the real audience – people like you – would take quantity for quality (“there is no smoke without a fire – he couldn’t invent, or misrepresented all these, right?”).
Particularly, if the reader had been already plied to be receptive to his message
with compliments ( “You are right to be alarmed” and with a sympathy as a fellow target of unfair criticism from the … trolls.
P.S. If you really haven’t expressed yourself well, and in fact you were just “ looking for either verification or an explanation ” then the answer is
“No, there are no reliable data to expect that at the current warming rate we will reach 3 C by 2050. 5 C by the end of the century!“, because the current warming rate
is below 0.3C per decade, not 0.64C.”
The situation is dire enough at the real warming rate, so no need to inflate it so much. Particularly that overexaggerating comes with the price – does not help the case, but actually harms it – the overexaggerated claims can, and are, used by fossil-fuel interests to throw the baby with the bathwater – to discredit ALL the climate science by associating it with very extreme claims that the science questioned: “ how can we believe ANYTHING you say when you predicted 3C warming by 205o “?
Thus if the doomers didn’t exist – the deniers would have to invent them. I divide the doomers into 3 categories:
1) false-flag operating denier trolls (without world’s dependence on fossil fuels – gone are the trillions from their exports, and with that
the economy, and therefore the regimes and the ability to finance wars/terrorism of the petro-states (Russia, Iran, Saudi Arabia, etc.)
2) those who don’t care about humanity and climate change – it’s all about them, about their ego ( if I, a scientific ignorant, can see what the top climate scientists failed, or refused, to see – then I must be really, really smart and virtuous)
3) well-intentioned individuals, who are unwittingly playing straight into the hands of the two above categories.
*P.S. If you really haven’t expressed yourself well, and in fact you were just “ looking for either verification or an explanation ” then the answer is*
Look, I’ve been visiting this site for a long time and I occasionally have questions. To imply anything other is ridiculous. You’re reading a lot into a simple post that requires one answer. Not some diatribe about trolls and me being used as a vehicle for some nefarious purpose. I’m very familiar with some of the trolls on this site and have complained about them often enough.
I’m not a scientist, just a musician. I’ll try to be more careful next time.
Some reflections on outsourcing one’s mind to AI (gift links):
The People Outsourcing Their Thinking to AI. Rise of the LLeMmings – https://www.theatlantic.com/technology/2025/12/people-outsourcing-their-thinking-ai/685093/?gift=n_xMk-Ah7x90dsBbxIEpEYD39bEaV_nwgNHPGQQ_z3w&utm_source=copy-link&utm_medium=social&utm_campaign=share “He told me that he uses AI for up to eight hours each day, and he’s become particularly fond of Anthropic’s Claude. Sometimes, he has as many as six sessions running simultaneously. He consults AI for marriage and parenting advice …
“The trouble with AI tools is that they seem to “exploit cracks in the architecture of human cognition,” … The human brain likes to conserve energy and will take available shortcuts to do so. “It takes a lot of energy to do certain kinds of thought processes,” Requarth told me; meanwhile, “a bot is sitting there offering to take over cognitive work for you.” … | “Chatbots are engineered to take advantage of this human tendency by offering compelling answers to any query, even if many of those answers are false or misleading.”
“Three years into the AI boom, an early picture of how heavy AI use might affect the human mind is developing. For some, chatbots offer emotional companionship; others have found that bots reinforce delusional thinking (a condition that some have deemed “AI psychosis”). The LLeMmings, meanwhile, are beginning to feel the effects of repeatedly outsourcing their thinking to a computer.”
Part 2 of my tear on AI/Data Centers:
Here’s How the AI Crash Happens. The U.S. is becoming an Nvidia-state. – https://www.theatlantic.com/technology/2025/10/data-centers-ai-crash/684765/?gift=n_xMk-Ah7x90dsBbxIEpERVngX4-wKXRisE7EAFsQQM&utm_source=copy-link&utm_medium=social&utm_campaign=share [this does not address toxicity, extreme water/resource/land use, noise etc.]
“this data-center campus, far from complete, already demands more than 500 megawatts of electricity to power these calculations—as much as hundreds of thousands of American homes. When all the data centers in New Carlisle are built, they will demand more power than two Atlantas.
“The amount of energy and money being poured into AI is breathtaking. Global spending on the technology is projected to hit $375 billion by the end of the year and half a trillion dollars in 2026. Three-quarters of gains in the S&P 500 since the launch of ChatGPT came from AI-related stocks; the value of every publicly traded company has, in a sense, been buoyed by an AI-driven bull market. To cement the point, Nvidia, a maker of the advanced computer chips underlying the AI boom, yesterday became the first company in history to be worth $5 trillion.”
“It’s clear that AI is both drowning out and obscuring other stories about the wobbling American economy. That’s a concern. But even worse: What if AI’s promise for American business proves to be a mirage? What happens then? …. | For now, money is still pouring into the AI industry. But there’s also something circular about these investments.” …. | The biggest lesson of the past two decades of Silicon Valley is that Meta, Amazon, and Google—and even the newer AI labs such as OpenAI—have remade our world and have become unfathomably rich for it, all while being mostly oblivious or uninterested in the fallout. They have chased growth and scale at all costs, and largely, they’ve won. The data-center build-out is the ultimate culmination of that chase: the pursuit of scale for scale itself. In all scenarios, the outcome seems only to be real, painful disruption for the rest of us.”
Part 3: Water
AI Is Taking Water From the Desert. New data centers are springing up every week. Can the Earth sustain them? – https://www.theatlantic.com/technology/archive/2024/03/ai-water-climate-microsoft/677602/?gift=n_xMk-Ah7x90dsBbxIEpEXA85KToPUy39aRK3K7LLLI&utm_source=copy-link&utm_medium=social&utm_campaign=share [extract choices here somewhat arbitrary]
“generative-AI applications in particular can be orders of magnitude more energy-intensive than the predictive-AI applications that came before. “We still don’t appreciate the energy needs of this technology,” OpenAI CEO Sam Altman said in January at Davos. “There’s no way to get there without a breakthrough.” In the meantime, tensions over data centers’ water use are cropping up not just in Arizona but also in Oregon, Uruguay, and England, among other places in the world.”
“With more than 8,000 data centers whirring all around the world and venting heat, and many more on their way, that optimism may come off as nothing more than faith: Technology has gotten us into this predicament; perhaps technology will get us out of it.” [more tech bro evangelism – all for me, none for thee – aka socializing risk while privatizing profit – and the delusions about immortality – wow1]
Something interesting on direct air capture of CO2, with calculations which show just how much electricity it may need:
https://andthentheresphysics.wordpress.com/2025/12/17/direct-air-capture/
Nigel: referring to an ” …and Then There’s Physics” article calculations of electricity needed for [direct air capture of CO2]:
A key point is that given an atmospheric concentration of 400 ppm and a temperature of 300K, it takes a minimum of 19505 J to remove 1 mole of CO2.
How have they come up with these precisely looking (five significant digits??) calculations?
To what it relates? It looks like some thermodynamic concentration of atm. CO2. What for?
Without limitless free energy – no sane person would propose it as a cost effective way of DAC.
And if I instead plant a tree and during its life it sequesters 1 ton of CO2 in its wood – what would I need their “4.43 x 10^8J” for?
Piotr,
The energy-powered DAC takes a shed-load of energy. The tree-powered DAC requires massive land area.
Maybe seaweed DAC is the answer!
MA Rodger “Maybe seaweed DAC is the answer!
As with other climate solution, there is no seaweed, I mean, silver bullet.
DAC from reforestation, could be complemented by DAC from seaweed, complemented _if_ we could figure out the right place and approach that would work by the iron fertilization (the early 2000s mesoscale experiments poured cold water on John Martin’s quip “Give me a half a tanker of iron and I’ll give you the next ice age”), complemented by DAC from improved soil management, complemented by DAC via enhancement of geological uptake (CO2 taken up by weathering of carbonate and silicate rocks).
And those “nature-inspired” DAC, could possibly be complemented by “chemistry DAC”
mixture of chemicals that react with atm Co2, and can be then scrubbed and reused
(not to confuse the absurd physical concentration DAC discussed in the article) – of the type of:
https://www.spacedaily.com/reports/Helsinki_chemists_develop_low_temperature_direct_air_capture_fluid_999.html
But the take home message – DAC should be used to mop up the last few% of the CO2 emissions that were “the highest hanging fruit” for Co2 emission reduction, but most of the work on the way to net zero has to be done by reductions in emissions.
Piotr,
Thentherewasphysics commentary on DAC: “A key point is that given an atmospheric concentration of 400 ppm and a temperature of 300K, it takes a minimum of 19505 J to remove 1 mole of CO2.”
Piotr said: “How have they come up with these precisely looking (five significant digits??) calculations? To what it relates? It looks like some thermodynamic concentration of atm. CO2. What for?”
Nigel: I was wondering myself. I simply don’t know enough physics to sort it out. I asked Microsoft copilot:
“In relation to DAC (direct air capture of CO2) someone made this statement. “A key point is that given an atmospheric concentration of 400 ppm and a temperature of 300K, it takes a minimum of 19505 J to remove 1 mole of CO2.” Is this correct and how was it derived.”
Copilot: Yes, that number is essentially correct, and it comes straight from basic thermodynamics of mixing/separation.
(unfortunately the copy and paste is unable to properly show some of the equations but if you ask the nice friendly copilot I assume it will give you the more readable version). Anyway here it is:
———————–
1. Where the 19,505 J/mol comes from
For an ideal gas mixture, the minimum reversible work to separate one component from a mixture at constant temperature and pressure is given by the change in Gibbs free energy associated with “un-mixing” that component.
For CO₂ in air at mole fraction x, the minimum work per mole of CO₂ is
W_{\mathrm{min}}=RT\ln \left( \frac{1}{x}\right)
at temperature T, where R is the gas constant. This is standard in treatments of gas separation and CO₂ capture thermodynamics.
Plug in the numbers:
– Gas constant:
R=8.314\ \mathrm{J}\, (\mathrm{mol^{\mathnormal{-1}}}\, \mathrm{K^{\mathnormal{-1}}})
– Temperature:
T=300\ \mathrm{K}
– CO₂ in air:
x=400\ \mathrm{ppm}=400\times 10^{-6}=0.0004
First compute RT:
RT=8.314\times 300\approx 2494\ \mathrm{J/mol}
Then the logarithmic term:
\ln \left( \frac{1}{x}\right) =\ln \left( \frac{1}{0.0004}\right) =\ln (2500)
Approximate:
\ln (2500)=\ln (25)+\ln (100)\approx 3.219+4.605=7.824
Now multiply:
W_{\mathrm{min}}=2494\times 7.824\approx 19,500\ \mathrm{J/mol}=19.5\ \mathrm{kJ/mol}
So the quoted value 19,505 J per mole of CO₂ at 300 K and 400 ppm is consistent with the standard thermodynamic minimum.
2. What assumptions are baked into this
This result assumes:
– Ideal gas behavior and ideal mixture (no interactions beyond ideal).
– Isothermal, isobaric, reversible separation.
– Initial state: CO₂ in air at 400 ppm.
– Final state: pure CO₂ at the same temperature and pressure.
In that ideal limit, the minimum separation work equals T\Delta S (or \Delta G, since it’s constant T,p), which for ideal mixtures gives exactly the RT\ln (1/x) dependence you see above.
In practice, real DAC systems require several times this minimum because of irreversibilities, sorbent/regeneration losses, pressure drops, etc. Literature values for the theoretical minimum for air-capture are in the same ballpark (~0.2–0.5 GJ per tonne CO₂ ≈ 4.5–11 kJ/mol), depending on how the process is defined and what concentration you’re separating to/from; 19.5 kJ/mol is the strict thermodynamic limit for going from 400 ppm directly to pure gas at the same T and p.
If you’d like, we can extend this to:
– compare that minimum to heat/electricity usage of actual DAC plants, or
– redo the derivation fully from the entropy of mixing expression \Delta S_{\mathrm{mix}}=-nR\sum x_i\ln x_i.
————————————-
Piotr: Without limitless free energy – no sane person would propose it as a cost effective way of DAC.
Nigel: Agreed. At no stage did I support or promote DAC. I didn’t think I needed to mention my position. I thought the numbers in the study spoke for themselves, showing the idea is very expensive and so doesn’t look viable. It is clearly more economic and sensible to stop the CO2 getting into the atmosphere in the first place.
However this does leave the problem that renewable energy and electrification allegedly cant solve all transport problems, so reliance is being placed on at least some limited extraction of CO2 to get to “net zero” Maybe DAC would help there but I haven’t looked at the costs / benefits and I’m sceptical.
Piotr: And if I instead plant a tree and during its life it sequesters 1 ton of CO2 in its wood – what would I need their “4.43 x 10^8J” for?
Nigel: OK, but you have the land area problem as MAR mentioned. Its very hard for me to see how we would find huge areas of land especially given a growing population. You would find some waste land too steep to farm but the numbers I’ve seen aren’t large.
Other alternatives are regenerative farming, but its very difficult keeping the carbon in the ground. And basalt rock weathering where the rock is crushed and sprinkled on the ground, but its also quite an energy intensive process. But given natural weathering is doing some of the work, surely it would use less energy overall than DAC? But the process is slow so Im not sure it would help much getting us to net zero. Its more of a tool to mop up CO2 over the longer term.
Seaweed? You would need vast volumes of sea weed. How would that work? What would that onslaught do to ocean ecosystems?
Theres certainly no easy answer to this extraction of CO2 thing.
Clarification of my response to Piotr. By ‘DAC’ I was referring to the type of carbon capture that sucks CO2 out of the air with fans. This is the way the term seems to be generally used. There are other ways of extracting carbon, that I listed.
Nigel: ‘DAC’ I was referring to the type of carbon capture that sucks CO2 out of the air with fans.”
And my criticism of your source is that they behave as if they criticism of the most primitive – brute energy physical concentration of CO2 – applied to all forms of DAC. It doesn’t – so by conflating DAC with its most ineffective form – they help to throw baby with bathwater:
And those other form that I have described – both “nature-inspired” DAC which you recognized even if you seem to exaggerated their limitations, and the chemistry DAC
that you didn’t mention, are not burdened with the huge energy costs of the physical extraction of Co2 from the air.
Nigel: “This is the way the term seems to be generally used.”
I am not sure about. Note the DAC in the link I gave:
https://www.spacedaily.com/reports/Helsinki_chemists_develop_low_temperature_direct_air_capture_fluid_999.html
I would suggest that it is the proponents of the physical extraction type of DAC that seem to be promoting their ineffective approach – as if it was the only realistic way of DAC.
Piotr,
“And my criticism of your source is that they behave as if they criticism of the most primitive – brute energy physical concentration of CO2 – applied to all forms of DAC. It doesn’t – so by conflating DAC with its most ineffective form – they help to throw baby with bathwater:”
I suppose they should have mentioned that other alternatives exist that require less human inputs of energy. All extraction of CO2 is going to use a lot of energy. but great if nature can supply some of that.
I do think the nature orientated approaches to sequestering carbon have some use and we should do what we can, The rock weathering has its positives as well. I should have mentioned that, but it was important to show the limitations. I notice you discussed their limitations in your second comment. I hadn’t actually seen that comment when I posted my first comment.
Piotr: “I am not sure about. Note the DAC in the link I gave. I would suggest that it is the proponents of the physical extraction type of DAC that seem to be promoting their ineffective approach – as if it was the only realistic way of DAC.”
The DAC people may be doing that. But Ive read quite a few articles on the issue and most people including the critics of DAC seem to use DAC in the sense of meaning extracting CO2 form the air with fans and they refer to tree planting and similar nature solutions as “carbon sequestration.” Not saying that is the logical thing because they all capture CO2 directly from the air but we are probably stuck with the convention and should go with the flow. I notice that TK made a similar comment so I don’t think it’s in my imagination.
Nigelj,
I’m not sure that AndThenThere’sPhysics post is managing to pull the “wood” of the carbon capture problem out from in the “trees” of the physics & technology of Direct Air Capture. It certainly left me scratching my head.
The figure given for the minimum theoretical energy requirement for DAC = 0.443Gj/t(CO2) is derived (see 25-minute video in post) from the thermodynamics** with 27ºC & 400ppmCO2 and then suggests a 10% efficiency (so 4.4 Gj/t(CO2) = 16 Gj/t(C)) and gives as perhaps in reality it being 5% (8.8 Gj/t(CO2) = 32Gj/t(C)).
I’m not entirely sure what the end-game was in the illustrative scoping comparisons in the video. The idea of natural gas being used to power DAC would suggest to me a useful comparison with the energy content of natural gas w.r.t to its carbon content (63Gj/t(Carbon-content)). And the word is that today’s natural-gas-powered DAC plants burn half the carbon they extract, which may be where that 5%=32Gj/t(C) comes from.
I don’t know whether these ‘half-the-carbon’ DAC operations calcs either simply account for DAC in this capture and are ignoring the exhaust CO2 from the power-generation, or whether they are achieving this 32Gj/t(C)-efficiency when including the captured CO2 from their own power-generation, gases which should be far more concentrated CO2 & thus an easier task to capture.
(** The equation used is the ‘isothermal expansion work’ one W = R.T.In[V2/V1]. I’ll assume this is correctly applied.)
The post also attempts to give some idea of the total scale of such required DAC operations.
Myself, I have taken this graphic (which is Fig 2 from Meinshausen et al (2020) ‘The shared socio-economic pathway (SSP) greenhouse gas concentrations and their extensions to 2500’), specifically fig2c the bottom left-hand thumbnail, and estimated it was saying that in the extended SSP1-1.9 scenario (to 2500AD) it was showing negative carbon emissions through the period 2050AD-2180AD, the volume of which would roughly equal all our net-positive emissions post-2007.
And in terms of the required DAC energy spread over 130 years, so far during the period since 2007 the overwhelming majority of our primary energy use has been fossil-fuel powered, in 2024 141PWh of 168PWh = 84%.
Back in 2007. CO2 was at 384ppm which if emissions stopped would have dropped with natural draw-down by perhaps 40ppm(?) in 150 years, so leaving a CO2 concentration at roughly the 350ppm mark.
And my own mad idea for DAC. If CO2 freezes at -80ºC and the South Pole winter gets down to -60ºC, would it be worth setting up plant down there to cool some of that South Polar air that extra 20ºC and watch the CO2 rain out?
Of course, once all that CO2 can be captured, storing it away safely somewhere becomes the next challenge.
MAR: “And my own mad idea for DAC. If CO2 freezes at -80ºC and the South Pole winter gets down to -60ºC, would it be worth setting up plant down there to cool some of that South Polar air that extra 20ºC and watch the CO2 rain out?”
Since getting anything to the South Pole, particularly the energy required to run it, is prohibitively expensive, in terms of $ and GHG emissions. Then there having people running machinery and maintaining it in -60C, with a windchill probably much lower than that. I have worked on a deck of the ship in -25C, and it’s not fun.
So if at all – I would suggest in Yakutia or somewhere in Siberia on there – where it gets really cold, where you have people and infrastructure and probably local source of energy – if you build it next to the natural gas fields. And I guess Russia would be interested in it –
if doable – two birds with one stone – being paid by the world for using their local gas,
and by reducing the pressure for the transition away from fossil fuels, extending the demand for their oil and gas,
In Re to MA Rodger, 31 Dec 2025 at 9:18 AM,
https://www.realclimate.org/index.php/archives/2025/12/unforced-variations-dec-2025/#comment-843301
Hallo MA,
I would like to comment on your idea of the hypothetical South Pole DAC plant, because it may be, in my opinion, a useful exercise.
First, we should consider that -78.5 °C is the temperature at which CO2 vapour pressure above surface of solid carbon dioxide reaches 101 325 Pa. Partial pressure of CO2 (at its present atmospheric concentration 430 ppm and at standard atmospheric pressure 101 325 Pa) is thus about 44 Pa only. To estimate CO2 sublimation point at this pressure, we can in a first approaching solve Clausius-Clapeyron equation for this compound. I asked LLM Gemini therefor (Ms. Anderson, please forgive) as follows:
“Provided that we have perfectly dry air, can you estimate a temperature of a solid surface at which carbon dioxide, having at its present concentration about 430 ppm a partial pressure about 44 Pa, would start to form frost on this surface?”
The provided result was 131 K, which is -142 °C. The engine added “for free” the following context:
Why it doesn’t snow CO₂ on Earth
Earth’s Record Low: The coldest ground temperature ever recorded on Earth is -89.2 °C (Vostok Station, Antarctica). This is still far too “warm” for CO₂ to freeze out of the air.
Mars Comparison: The atmosphere of Mars is 95% CO₂ with a partial pressure of about 600 Pa. Because the pressure is higher there (compared to Earth’s CO₂ partial pressure of 44 Pa), CO₂ frost forms at a warmer temperature, around -125 °C (148 K), which is why dry ice caps form at the Martian poles but not on Earth.
We see that on Earth, CO2 indeed fulfils the definition of a “non-condensing greenhouse gas” and that even under coldest conditions naturally occurring on Earth surface, we still would have to cool the air significantly more to freeze it out.
More detailed analysis will reveal that for an efficient CO2 removal, we need to cool the air below -150 °C, ideally to temperatures about -170 °C. With respect to energy efficiency of the separation process, this requirement may not represent a major drawback if we use heat exchangers for heat (or, rather, “cold”) recuperation.
There is, however, another aspect, common for all technical DAC processes, that is significantly more important for their technical and economic feasibility than the energy efficiency of the separation itself. It is the circumstance that the reasonable values (for both separation efficiency as well as energy efficiency) can be achieved only at slow flow rates that, at given high CO2 dilution in the ambient air and a high throughput required, unavoidably result in huge size of the necessary equipment and thus also in exorbitant investments that would have been necessary for building the respective facilities.
Let us assume a facility required for separation 1 Gt CO2 annually. The respective neat CO2 volume is 509 billion cubic meters, and this amount could be theoretically separated from some 1 180 000 cubic kilometres air. Considering that one tropical year has some 31 557 000 seconds, the necessary minimal flow rate of the ambient air through the considered facility will be about 37 393 000 m3/s. If we take 10 m/s for a reasonably achievable linear velocity of the respective air stream, the cross-section of the required “pipe” will be about 37.4 square kilometres.
Please consider that there is very questionable chance that we could “shrink” our model facility to a more reasonable size. It is because if you would like to keep the projected separation efficiency, rising linear velocity of the air stream will hardly save any volume of the necessary equipment – you may rather expect a trade-off between the necessary cross-section and the necessary length of the considered air stream. Sacrificing separation efficiency in favour of lower equipment size will hardly help as well, because this way, you will not achieve the required yield.
I am afraid that proponents of the bipartisan bill that allowed billions USD budget for building “pilot” DAC facilities in Louisiana and Texas have never showed these figures to the public (and to other representants and senators). If they did so, I cannot imagine that both chambers of the US Congress would anyway vote for the bill.
Best regards
Tomáš
A correction to my post of 31 Dec 2025 at 7:47 PM,
https://www.realclimate.org/index.php/archives/2025/12/unforced-variations-dec-2025/#comment-843318
Dear all,
The calculated 37.4 km2 cross-section of the pipeline for removing 1 Gt CO2 annually applies for linear velocity of the air stream 1 m/s. For linear velocity 10 m/s it would have been “only” 3.74 km2.
I apologize for my mistake.
P.S.
There was also an idea that as soon as electricity production in fossil fuel power plants will be replaced with cleaner sources, the existing cooling towers could serve for counter-current CO2 extraction from the ambient air, e.g. with an aqueous sodium carbonate solution (to form NaHCO3 that could be then thermally decomposed back to Na2CO3 and concentrated CO2.
This concept could perhaps work if all these power plants will be refurbished as nuclear, because cooling towers need the waste heat for keeping them running. In this scenario, roughly estimated capacity of all existing cooling towers worldwide might enable DAC withdrawal of some 0.4-0-8 Gt CO2/year.
Tomáš, you have amply demonstrated that DAC of CO2 by freezing is completely impractical, even at Antarctic temperatures.. One factor you omitted (although it was not necessary for your conclusion) is that the coldest Antarctic temperatures occur at high elevations in the interior, where the ambient air pressure is probably 75 or 80 kPa, rather than around 101 kPa.
Nigelj: thanks for reminding us of aTTP’s useful evaluation. Putting hypothetical numbers to impossible dreams is yet another way to remind us that we need to deal with the disease, not the symptoms, of global warming/climate change and other forms of toxic waste and excessive exploitation of resources on a finite planet.
We are so to our comforts and entertainments (honestly, sports and spectacle are out of control and getting worse, and crypto and AI excesses – wealth and power taking more and giving less). The idea of fitting our needs to reality is so unpalatable we dream that we can ‘fix’ the problem with some unknown technology in some ideal future. What we know is what we should heed. We need a great deal less stuff, and we certainly need to stop the lies, bullying, and looting. Must … stop … now.
And here is the comment I have left under the video the blog was referring to. The youtube video is 2 years old, so the correction there is, as they say closing the barn doors after the horses have been long sold for horse meat to Japan….
======
Fancy graphics, ominous music and the painfully slow delivery won’t change the fact that you are presenting a strawman – NO feasible DAC technology is based on the physical concentration of atm. CO2 to which your thermodynamics argument refers to – PRECISELY because the thermodynamics limitations of physical concentrations people have known for a long time.
The feasible DAC solutions do NOT need physical concentration of CO2 and fall into two categories:
– amplifying the natural process of CO2 uptake like plant and algal growth. or weathering of carbonate and silicate rocks, both of which get their CO2 from ambient air by diffusion,
-or a scaled up chemical reaction where the components of the “brew” take up CO2 chemically – again NOT REQUIRING physical concentration of CO2.
Sure, both still face the far from trivial problems of scaling up enough, ecological problems (say ocean fertilization), but those have to do with space, technology, and energy needed to run these systems, NOT the stupendous thermodynamic cost of the concentration process they DON’T USE.
In Re to Piotr, 31 Dec 2025 at 10:41 AM,
https://www.realclimate.org/index.php/archives/2025/12/unforced-variations-dec-2025/#comment-843304
Hallo Piotr,
Thank you for your points, I fully agree that any technical means for carbon dioxide removal (CDR*) from Earth atmosphere can hardly ever become technically and economically feasible.
I would like to add only that in my recent post submitted on 31 Dec 2025 at 7:47 PM,
https://www.realclimate.org/index.php/archives/2025/12/unforced-variations-dec-2025/#comment-843318 ,
I tried to show that the theoretical thermodynamic value of the respective mixing Gibbs energy may be of secondary importance for technical and economic feasibility of ANY practically applicable process for extracting a minority component from a very diluted solution thereof.
It is because this value can be reached only at negligible process throughputs or in facilities of an impossible size (and price). What matters more are thus (i) unavoidable trade-offs between real energy consumption in a facility designed for a required throughput on one hand and investments necessary for commissioning this facility on the other hand, and (ii) the circumstance that at high dilution of the separated component, a big (and commensurately expensive) equipment is anyway necessary for the required reasonable throughput.
I would like to thank you also for all other helpful exchanges with me and wish you all the best in the next year. As I equally appreciate all honest commenters and cannot individually approach everyone, please let me hereby send my thanks and greetings also to them, as well as to the moderators for keeping their website running.
Tomáš
*P.S.
I thought that the term “direct air capture” (DAC) is used just for the CDR methods exploiting a separation step that relies on technical means. If so, I would perhaps rather desist from using the term DAC for such CDR methods like tree planting, wherein the separation step exploits only natural processes and “means”.
https://carboncredits.com/solar-energy-developer-secures-415-million-to-power-the-worlds-largest-direct-air-capture-plant/
Hmm,
Not to be picky, but you link to a year-old report.
The report describes the power-project for a DAC scheme which itself plans to capture 500,000 tons(CO2) per year of the annual 40,000,000,000 tons(CO2) of global emissions. This 415MW scheme might provide a rough estimate of the energy requirement for DAC, quoted as saving 250,000 ton(CO2) presumably by being solar generation and then doubling this with the DAC (although there will maybe be FF-generated electric power that could have been avoided as an alternative). Worryingly, when I run a check on that claim, I don’t seem to get that level of emissions saving from the solar (22kt(CO2) for gas-powered, 40kt(CO2) for coal-powered) but that may be an untamed decimal point!
A 2023 Guardian article ridiculed the idea that an oil company is quoted using this to excuse for the continuing existence of fossil-fuel use, a project which reverses “about 260 seconds of the world’s (annual) emissions.” And it will be up-&-running in 2025? Apparently no sign of that yet.
The storage scheme is described as having 3,000,000,000 ton(CO2) capacity (so able to store far more than this one DAC plant) but details are seriously vague given a quoted 2025 (though slipped) start-date. The one bit of happy talk is the mention of this storage being a “saline aquifer” and not the usual old oil wells that need gas injection to boost output.
MA Rodger says – This 415MW scheme
1 Jan 2026 at 1:31 PM
a correction.
Not a 415MW scheme but a $415 Million scheme
Offering 145 MW Capacity.
ref
https://carboncredits.com/solar-energy-developer-secures-415-million-to-power-the-worlds-largest-direct-air-capture-plant/
Data (or whatever you call yourself),
Thank you. That helps a little. But reducing the ‘nameplate’ power rating by three won’t entirely compensate for the calculated power output being ten-times too low. I did note that the quoted “CO2 emissions avoided” was given as “250K MT” which doesn’t seem to make much sense either as an annual value or a life-time value. Would you have gleaned some words of wisdom on that mystery?
In Re to Hmm, 31 Dec 2025 at 10:24 PM,
https://www.realclimate.org/index.php/archives/2025/12/unforced-variations-dec-2025/#comment-843324
Dear Hmm,
Thank you for your reference.
In view of the reasons that I tried to explain in my post of 31 Dec 2025 at 7:47 PM,
https://www.realclimate.org/index.php/archives/2025/12/unforced-variations-dec-2025/#comment-843318 ,
I think that investing money collected for carbon credits into any form of DAC is basically equal to burning them.
For Occidental, the value is clearly in the created PR, namely in raising false public belief that continuing in their fossil fuel business is justified by, in parallel, removing (in fact, a negligible fraction of) the CO2 released by this business back from the atmosphere. If the enterprise is, moreover, financed by others, it is an excellent business deal for them. Unfortunately, an exact opposite for the rest of the world, I am afraid.
My personal opinion on such “decarbonization achievements”: Shame on all who contributed to shaping “climate policies” the way that enabled this scam – not only on the politicians who approved the rules, but also on all scientists and journalists promoting DAC as a possible alternative to reduction of fossil fuel consumption and thus confusing the public.
Best regards
Tomáš
Don’t worry, someone funded something.
Antarctica
↔
Seaweed
↔
Basalt
↔
$415M solar DAC plant
Different scenery.
Same refusal.
So yes — laugh.
That’s comedy. Dark comedy, but comedy nonetheless.
I checked ATTP’s discussion. Mostly circular.
Most discussions around DAC, net zero, and carbon budgets sound like a lot of technical back-and-forth, but beneath the noise there’s a deeper structural problem that few acknowledge. The core failure everyone is skating around is this: climate mitigation treats a living, historical, relational Earth as if it were a controllable machine — and mistakes abstractions for reality.
DAC is not the villain. Net zero is not the villain. Carbon budgets are not the villain. They are symptoms of a deeper refusal: to accept irreversibility, to accept inheritance, to accept that the scale and power of civilization itself are the problem. That’s why techno-fixes proliferate, limits are endlessly deferred, and language becomes euphemistic and circular.
All the debate about energy requirements, efficiencies, or LULUCF ratios is still operating inside the machine metaphor: inputs, outputs, efficiencies, substitutions. As Whitehead would say, they are mistaking abstractions for concrete reality. To put it sharply: you cannot budget the future of a system whose governing dynamics change as a function of its past. That is the dagger cutting through all these circular debates.
Too often the conversation is dominated by endless ‘we-need’ imaginings — hypothetical fixes projected onto everyone, as if collective virtue alone could override physical and historical constraints.
I was reviewing some past science explanations here, while wondering where we are now. One item stands out: did any of this really clear anything up yet about the so‑called warming spike and sudden acceleration?
https://www.realclimate.org/index.php/archives/2025/03/wmo-update-on-2023-4-anomalies/
https://www.realclimate.org/images//WMO-SOTC24-SchmidtHausfather.pdf
Looking back at the 2023–24 GMST spike, it’s clear the anomaly exists, is physically meaningful, and remains only partially explained. Yet the community narrative has largely minimized it — framing it as “within expected variability” using wide uncertainty envelopes and probabilistic language, and emphasizing long-term trends rather than the unusual short-term jump.
Hansen’s physics-driven perspective, highlighting over-ocean EEI, aerosols, and cloud feedbacks, remains plausible but largely absent from synthesis papers. Acceleration in surface temperatures is understated; new records are noted, but the discussion rarely emphasizes how rapid or exceptional the spike was.
In short, the 2023–24 anomaly is still there, but its significance has largely been buried in narrative framing, leaving the gap between the data and the discussion surprisingly wide. My instinct is that we’ll have to wait another year or two before we get a true “England + Cowtan & Way moment” for this spike.
Hiatus context — Matthew England (Australia):
The “hiatus” in global surface warming (~1998–2012) puzzled the community because surface temperatures seemed to stall while greenhouse gases continued rising. England and colleagues proposed the tropical Pacific / ocean heat uptake mechanism — specifically, enhanced La Niña–like conditions drove more heat into the deep ocean, temporarily masking surface warming.
Key paper:
England, M.H., McGregor, S., Spence, P. et al. (2014) “Recent intensification of wind-driven circulation in the Pacific and the ongoing warming hiatus.” Nature Climate Change, 4, 222–227.
Extract: “Enhanced trade winds in the tropical Pacific drive more heat into the deep ocean, explaining the slowdown in surface warming.”
This work largely predated or overlapped with Cowtan & Way’s 2014–2015 paper on temperature coverage bias, which corrected gaps in Arctic/remote data and partially “recovered” surface warming during the hiatus.
This work largely predated or overlapped with Cowtan & Way (2014–2015), which corrected gaps in Arctic/remote data and partially “recovered” surface warming during the hiatus. Together, these contributions resolved the hiatus puzzle.
Maybe one day the 2023–24 warming anomalies will be equally explained, using real data and a dose of common sense.
Data: “Looking back at the 2023–24 GMST spike, it’s clear the anomaly exists, is physically meaningful, and remains only partially explained. Yet the community narrative has largely minimized it — framing it as “within expected variability” using wide uncertainty envelopes and probabilistic language, and emphasizing long-term trends rather than the unusual short-term jump.”
“Hansen’s physics-driven perspective, highlighting over-ocean EEI, aerosols, and cloud feedbacks, remains plausible but largely absent from synthesis papers. Acceleration in surface temperatures is understated; new records are noted, but the discussion rarely emphasizes how rapid or exceptional the spike was.”
The warming spike in 2024 specifically has been well explained by a combination of AGW, el nino, aerosols reductions (using mainstream estimate of aerosol forcing number, not Hansens high number), and the solar cycle and this website did an analysis on that and I posted a study by Carbon Brief on it written by Zeke Hausfather here:
https://www.carbonbrief.org/analysis-what-are-the-causes-of-recent-record-high-global-temperatures/
The unusually intense warming in 2023 has not been as well explained. Even when accounting for AGW aerosols and el nino and the solar cycle, its still not fully explained. as Zeke mentions. It has indeed been framed as within the bounds of natural variability which isn’t a full explanation.
Hansens explanation for both 2023 and 2024 unusual warming is that aerosol reductions are a huge factor, starting around 10 years ago in China, and shipping aerosol reductions around 2020, where the energy was sequestered in the oceans and came out over that period 2023 – 2024 el nino. given el ninos release heat. He claims aerosols have a larger forcing effect than the mainstream science.
It is quite convincing except when you apply it to 2023, because the unusual levels of heating were evident before this year truly morphed into an el nino so why would the heat be expelled at that stage? And if his very high estimation of aerosols would still somehow explain 2023 temperatures, then 2024 should be warmer than it was assuming Hausthfathers analysis is correct on things like the solarcycle. So 2023 is still a mystery. But IMO Hansen is putting very useful ideas on the table for consideration. He leads the way.
December 2025 saw global temperature anomalies dropping down quite sharply after the warm wobble of Sept-Nov.
ClimatePulse has but one day yet undeclared and the Dec-to-date anomaly is sitting at +0.48ºC. (Sept-to-Nov averaged +0.67ºC while Jun-Aug averaged +0.47ºC, these all down on the start of the year with Jan 2025 +0.79ºC.)
The warmth of Sept & Oct was due to the SH with a lot of that down to an abnormally warm Antarctic. Down there you regularly see wobbles of +/- 3ºC but wobbles usually not lasting anything like two months. With the Antarctic comprising 10% of the SH, such a long Antarctic wobbles did impact the SH Sept/Oct anomalies and also the global anomalies for Sept & Oct. The Sept-Oct wobble was enough to give a record annual Antarctic anomaly of +1.2ºC which is +0.6ºC above recent years. (So that Antarctic wobble was enough to add an unexpected +0.025ºC to the global 2025 average.)
The warm anomaly of Nov was a NH thing and not unexpected. In the NH, Autumn warming has been more pronounced than that of the other seasons and the resulting anomaly wobble is often quite a feature, although less-so in La Niña years. So far, this 2025 NH wobble seems quite short-lived, even with the developing La Niña.
With the anomaly of +0.48ºC, December 2025 becomes the 5th warmest December on the ERA5 record, below 2023 (+0.84ºC), 2024 (+0.76ºC) and below =3rd 2019 & 2015 (+0.54ºC), both the latter boosted by El Niño, with 2025 sitting ahead of 6th-place 2017 (+0.37ºC), 2016 (+0.34ºC) & 2018 (+0.33ºC).
Note there has been a bit of underlying AGW since 2018 and Dec 2016, 2017 & 2018 all sat above the 2010-22 linear regression line. December 2025 sits below that projected 2010-22 warming rate and is the 4th 2025 month (along with Jun, Jul & Aug) in ERA5 sitting below that rate. Previously, the most recent was back in May 2023.
Without the rather pronounced Sept-Nov warm wobble, the 2023-24 “bananas!!” temperatures could be surely declared dead and buried. And even so, I can’t see it as resulting from any reduction in aerosol pollution which is a NH effect (making it very unlikely) and permanent (making it surely impossible).
The annual ERA5 anomaly thus comes in at +0.59ºC, this only a shade below the 2023 average (+0.60ºC) but well below 2024 (+0.72ºC).
(In ‘above pre-industrial’, that’s 2024 = +1.60ºC, 2023 = +1.48ºC, 2025 = +1.47ºC.)
With the early months of 2025 still running with “bananas!!” anomalies, the 2025 annual anomaly sits above the 4th warmest year (2016 +0.44ºC), 5th (2020 +0.43ºC) & 6th 2019 (2019 +0.34ºC).
For up-to-date graphics of the various temperature anomalies, see The Banana!! Watch page.
In ‘above pre-industrial’, that’s 2024 = +1.60ºC, 2023 = +1.48ºC, 2025 = +1.47ºC.
[just taking these at face value, unconfirmed]
Let’s be clear: the 2023–24 GMST spike — the so-called “Bananas!!” anomaly — is real and physically meaningful.
No cherry-picked NH aerosol adjustment, no local wobble, no post-hoc statistical contortion can erase it. It survives scrutiny across ERA5, satellite datasets, and multi-model comparisons. Attempting to attribute it solely to a short-lived NH aerosol reduction is inconsistent with physics and observations: the effect would be regional, transient, and far smaller than the global anomaly we saw.
Hansen’s acid test remains valid: the abrupt magnitude, persistence, and hemispheric spread of the spike confirm something unusual happened — energy was redistributed, feedbacks amplified, and surface temperatures jumped well above expectations. Your data — whether looking at Antarctic wobbles, seasonal NH/SH offsets, or annual averages — only confirms this.
In short: the “Bananas!!” temperatures are not an artifact, they are not explainable by simplistic aerosol arguments, and they are not “dead and buried.” They happened. They are real. Deal with it.
Data (or whatever you call yourself),
The problem with this particular word salad you serve up here is that the ‘Hansen’ position you argue to support is contradicted by the absence of on-going “bananas!!” today, these both being positions you argue to support.
That is the ‘Hansen’ acid test was to show that the “bananas!!” were caused by reduction in aerosols or in feedbacks, this the ‘Hansen’ position. with both aerosols or feedbacks pointing to a high ECS. This ‘Hansen’ position is the opposite of the other position you argue for here. That is ‘Hansen’ is not supported by failure of his acid test where the “bananas!!” that once “happened” today are gone.
Perhaps you could tell that to your AI bot and it can then do better arranging its answer-ducks in a proper row.
Allow me to summarize and hopefully put this to bed once and for all.
Last month, I wrote to Atomsk’s Sanakan: “~2°C by 2045-2050 is blatantly false and unfounded.”
Context here: https://www.realclimate.org/index.php/archives/2025/12/unforced-variations-dec-2025/#comment-843073
Atomsk’s Sanakan claims: the observed warming trend, better observationally-constrained CMIP6 models, CMIP5 models, the IPCC, etc., show we’re on pace for ~2°C by 2045-2050, 3°C by 2075-2090 (2060 at the earliest), and ~3.5°C by the end of the century.
Simultaneously, he claims: the German Physical Society (DPG) and the German Meteorological Society (DMG) are cherry-picking a small number of CMIP6 models known to overestimate warming, including up to 2025 — and if those models are too warm in 2025, they will also be too warm for 2050.
Across two months of fragmented threads, Atomsk offers a mix of non-peer-reviewed “references” — Forster 2025, Copernicus, Carbon Brief, ERA5 — presented as if they were confirmed projections. I have checked each source individually; none definitively supports the precise numbers he asserts. These references provide plausible ranges or scenario envelopes, not point predictions.
By combining multiple assumptions and datasets into a single narrative, Atomsk creates the impression of certainty where none exists. This rhetorical strategy — confident language, volume, and selective references — conceals the underlying uncertainty. Readers should treat such aggregated claims as illustrative, not authoritative, and distinguish between scenario envelopes and validated projections.
AS also provided a link to the warming projections in the last IPCC report, and even the worst case RCP8.5 scenario didn’t get to 3 degrees by 2050. So is the IPCC report crap as well?
Yup, Nigelj. The sockpuppet moved their response down here to make it harder to see the posts where I did that. Here I cited this from IPCC 2021 figure SPM.8. They also don’t understand the difference between projections vs. predictions.
And they’re willfully disinforming. For example, they said “Atomsk offers a mix of non-peer-reviewed “references” — Forster 2025, Copernicus, Carbon Brief, ERA5“. But that’s a lie since Forster 2025 was peer-reviewed. There’s even a tab at the paper’s link naming peer reviewers, showing their reviews, etc. The sockpuppet also left out other peer-reviewed sources they were cited, such as IPCC reports, Xu 2018, Dai 2023, and Hansen 2023. They tried to hide that from people by moving their response down here and not linking to what they’re responding to. Good illustration of how these Data/Jim/Neurodivergent/Mo Yunus/… sockpuppet accounts try to deceive people. How they respond (or don’t respond) to being caught on this obvious disinformation should further reveal their character.