This month’s open thread. As usual try to remain substantive and avoid insults and personal attacks on other commenters. Any sock-puppetry or abusive comments will just be deleted on sight. Also, please don’t outsource your comments to ChatGPT – cut-and-pastes of long-winded LLM output are tedious and add precisely nothing to the conversation. There are real things happening in climate – please focus on them.
Reader Interactions
285 Responses to "Unforced Variations: Sep 2025"
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I wish them luck. Seriously.
Scientists breathe new life into climate website after shutdown under Trump
There’s nothing there at climate.us. Until something shows up, have to be wary … volunteer efforts of this scale are more hope than anything else.
There already was a site focused on discussing natural climate change such as modeling El Ninos called the Azimuth Project, but it was mostly deleted by the owner, with vestiges and remains on the Wayback Machine at: https://web.archive.org/web/20190130165945/http://azimuthproject.org/azimuth/show/Azimuth+Project
I tried resurrecting it at https://azimuth-project.github.io/
Bill McKibben has an interesting take on Trump & Associates ability to bully other nations into reversing their efforts to develop/expand renewable energy sources:
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Trump’s Big Stick Might be…Kind of Puny
Can we actually force the rest of the world to make our energy mistake?
https://billmckibben.substack.com/p/trumps-big-stick-might-bekind-of
It might even be counterproductive: the tariff cudgel is inflicting a lot of unprovoked pain. One response is of course appeasement (especially when it can be mostly performative, in hopes of leaving the appeaser free in more practical terms largely to do what they wanted anyway). Another is resistance and even spite.
Good morning Kevin. I read the following this morning, remembered your comment above, and thought the Guardian opinion piece below was interesting and expands the point you make:
.
One by one, leaders learn that grovelling to Trump leads to disaster. When will it dawn on Starmer?
As the US president’s state visit looms, he’s leaving a trail of broken promises across the globe. Britain can’t afford to look like a lackey state
Simon Tisdall
Sun 7 Sep 2025 01.00 EDT
https://www.theguardian.com/commentisfree/2025/sep/07/donald-trump-keir-starmer-world-leaders-state-visit-uk
OT: on the plus side, Sunday NFL is back! And the Chiefs and Cowboys have already lost this week, a great start in my book ;-)
Thanks, David–well-spotted.
The visit is on as we speak, and the government and Crown are clearly collaborating to use British soft power (in the form of Trump’s admiration for extravagance, pomp, and opulent display, and perhaps a kind of legitimacy that Trump envies but himself will never possess) to put him in a good mood heading into the negotiations tomorrow. Hopefully it works to minimize the damage that he will do in relevant matters.
While the abilities of a crazy US president to “bully other nations into reversing their efforts to develop/expand renewable energy sources,”, the presence of such an administration strutting about the White House does embolden similar lunatics in other countries, and it is likely there are funds flowing out of the US supporting their campaigning.
And that can be a big problem.
Here in UK we have a carbon copy of MAGA called ReformUK that has been sitting head-&-shoulders above all others in the national polls for about 5 months now.. That’s about the time we have local elections when ReformUK gained control of 10 English county councils including Kent. And tonight Kent CC will debate a motion ‘Rescinding the KCC Climate Emergency Declaration’. (The rationale for such a move is set out HERE, the sort of BS often debunked here at RC.)
Happily, there is one issue where ReformUK becomes unpopular. That is its links to a certain Donald J Trump and when that particular individual gets his comeuppance (which surely can’t be too long in arriving), the stupidity of supporting an English version of the same will hopefully lose its appeal.
Hi MAR, Read this earlier today in Politico EU concerning ReformUK and the UK branch of its American “helpers.” Thought I’d pass it on:
.
“The Trump-aligned climate skeptics advising Britain’s Nigel Farage”
https://www.politico.eu/article/donald-trump-britain-nigel-farage-reform-uk-heartland-institute-climate-skepticism/
.
Good luck to all in Kent at this evening’s meeting.
No “spirited debate” allowed at Trump administration EPA.
Administrator Lee Zelden testified in January that “climate change was real and an urgent issue that must be addressed” in remarks to Senator Bernie Sanders in his confirmation hearing.
https://www.nbcnews.com/now/video/zeldin-says-climate-change-must-be-addressed-at-senate-confirmation-hearing-229479493891
Now, the agency has fired 5 and sent removal notices to 4 others who “signed a June declaration decrying moves that contradict science and undermine public health”. Scientific American has details.
https://www.scientificamerican.com/article/epa-fires-5-employees-who-signed-dissent-letter/
Zeldin has a reputation as more of a pragmatic conservative from blue New York State, and Trump himself is not well read or capable of administrative decisions that go much beyond how they affect him. This makes it easy for unelected officials to implement changes similar to those proposed by Project 2025′ Bernard Mcnamee who called for “cutting funding to DOE’s Grid Deployment Office, in part to stop ‘focusing on grid expansion for the benefit of renewable resources or supporting low/carbon generation.’ Instead, he calls for strengthening grid reliability, which he describes as expanding the use of fossil fuels and slowing or stopping the addition of cleaner energy.”
https://web.archive.org/web/20231110135235/https://www.politico.com/news/2023/07/28/far-right-climate-plans-00107498
“Want to work for National Weather Service? Be ready to explain how you agree with Trump”
https://apnews.com/article/noaa-trump-national-weather-service-job-application-b5969b014fed01adffc7c90901fd00fc
.
If you’re willing to put up a picture of Trump in your home, will that help increase your chance of being hired as a forecaster?
David: ” If you’re willing to put up a picture of Trump in your home, will that help increase your chance of being hired as a forecaster?
Better still if you can put 3-storey high picture of him on the outside of your building:
https://www.newsweek.com/department-labor-trump-portrait-2119185
a practice reminiscent of the loyalty pledges featuring massive portraits of Lenin, Stalin, Mao or the N. Korea Kims. You can’t go wrong with that – after all we are dealing with the guy who imposed 50% tariffs on India for their refusal to credit him with stopping the military conflict with Pakistan, and refusing to nominate him for the Nobel Peace Prize for that, the way Pakistan did.
Trump’s cabinet meetings provide a good indication of the type of groveling,, servile debasement expected–as Jay Kuo has termed it: butt snorkeling.
OOPS! Here’s the article on NO MORE employee unions in NASA, NOAA, etc:
https://www.space.com/space-exploration/nasa-employees-fear-worsening-conditions-as-new-trump-executive-order-eliminates-their-right-to-unionize
What a find!
While some “skeptics” limit themselves to ways to sabotage the comment section on science blogs because of their own resentments, there are relatively few that celebrate the sabotage of the career paths currently available in the field of climate science. Again, because of their own resentments.
DOAK: thank you for showing up. KIA exhibits extravagant reality denial.
Thanks Susan. I really don’t like doing this, but I will.
Some of us have been here a long time. We know there are actual scientists here that comment from a position of real expertise. Most of the rest of us are interested learners, and for our own individual reasons, we just “like this stuff”. Some are obviously here in need of attention. I think it’s pretty reasonable to believe that almost all of the regular readers here are more knowledgeable about climate science than the average person, maybe more knowledgeable than the vast majority of people simply because of our exposure to the posts by the experts and commenters with citations, ironically, even the trolls. They pretend not to know, but they know.
That being said, if someone’s online persona requires them to waste other people’s time because of their need for attention, that’s fair game for commentary – criticizing an internet personality. And, if that online persona brags about their support for politicians that are convicted felons, adjudicated sex offenders, suspected pedophiles, and documented racists, and support calls for the suffering of others, well, they can never really “take that back”. They have continuously, of their own free will, decided they no longer want to be treated as a decent person. At least that’s how I will always see them.
KiA, Your joyful b.s. pest-like troll is so foolish. Courtesy of CNN earlier today:
“4️⃣ Aviation safety
Fewer meteorologists are working with air traffic controllers due to burnout, fatigue and low morale, as well as other factors, including the Trump administration’s hiring freeze and deferred resignations, a new report said. National Weather Service meteorologists support air traffic command centers and air route control centers by providing updates about weather events that could impact operations and safety. Currently, only eight of the country’s 21 “weather service units” are fully staffed with four meteorologists. Oakland, California; Boston; Washington, DC and Jacksonville, Florida, have two or fewer meteorologists on staff. As of June, five of these units were also missing a local meteorologist-in-charge. According to the Government Accountability Office, urgent actions are needed to address these staffing issues.”
.
https://www.cnn.com/2025/09/04/us/5-things-to-know-for-sept-4-harvard-health-care-maine-mass-shooting-aviation-safety-climate-change
Mr. KIA, Don’t forget your snorkel.
Tomáš Kalisz,
You 1st Sept comment on the August UV thread was saying “that anthropogenic interferences with water availability for evaporation from the land might have changed climate sensitivity,” adding that “although this topic is potentially relevant for climate science and climate policies, it might have been neglected so far.”
The drying of the continents through AGW is something which the climate science is aware with research ongoing. Thus a reading list of recent stuff for you:-
. . Berg et al (2017) ‘Divergent surface and total soil moisture projections under global warming’
. . Qiao et al (2023) ‘Soil moisture–atmosphere coupling accelerates global warming’
. . Zuo et al (2024) ‘Importance of soil moisture conservation in mitigating climate change’
. . Tao et al (2025) ‘Emergent constraints on global soil moisture projections under climate change’
. . Liu et al (2025) ‘Global greening drives significant soil moisture loss’
. . Seo et al (2025) ‘Abrupt sea level rise and Earth’s gradual pole shift reveal permanent hydrological regime changes in the 21st century’ (ABSTRACT) with CarbonBrief coverage
The potential for significantly “changed climate sensitivity” from declining soil moisture and any resulting potential for AGW mitigation action addressing soil moisture is not something I see looming large in the literature. But then, I’m not looking very hard.
MAR: to Tomas K. The potential for significantly “changed climate sensitivity” from declining soil moisture and any resulting potential for AGW mitigation action addressing soil moisture is not something I see looming large in the literature
perhaps because, as it have been explained dozens? hundreds? of times to Tomas Kalisz – because of the massive volumes of water in background water fluxes , and the ~ 1-week of the residence time of H2O in the atmosphere – there is no feasible “mitigation action addressing soil moisture” (see my calculations of the costs of Tomas’s Sahara irrigation scheme that would require many TRILLONS of dollars each year, which after CENTURIES of spending would result in reduction the AGW by a fraction of a fraction of 0.3K, even that assuming ZERO GHG emissions to evaporate many cubic km3 of water and distributing it over many mln km2. The only feasible way to change the water cycle is via reduction of GMST via reductions of the GHG concentration – i.e. the very method that Tomas Kalisz, JCM and other “anything but GHGs” deniers – have tried to disparage for years.
in Re to Piotr, 2 Sep 2025 at 10:57 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838726
Dear Piotr,
I think that I have already (maybe more than once) confirmed that attempts to enhance water availability from the land by artificial irrigation (and influence Earth global climate this way) may not be practical.
As I also already attempted to explain, it does not, however, disprove my opinion that clarification if climate sensitivity depends on water availability for evaporation from the land may be still important. If land desiccation increases climate sensitivity, as some authors seem to assume, it can be helpful if we restrict or (ideally) avoid activities that may further strengthen this trend or contribute thereto.
I do not see a conflict with efforts for restriction of anthropogenic emissions of greenhouse gases (GHG). I rather suppose that there might be a positive synergy in global warming mitigation, between preventing further deterioration of land hydrological regimes on one hand and decreasing anthropogenic GHG emission on the other hand.
Oppositely, in case that anthropogenic land use indeed have increased climate sensitivity to GHG emissions, we may risk that neglecting this contribution and (instead of working in both directions) focusing solely on the GHG emissions itself may finally prove as inefficient – a money and time wasting without the desired / expected effect.
Best regards
Tomáš
Tomas: I have already confirmed that attempts to enhance water availability from the land by artificial irrigation (and influence Earth global climate this way) may not be practical.
Just for the record, since it was you who incessantly pushed that absurd proposal,
by “I confirmed” you mean “I was forced to admit it”, right?
Tomas “ It does not, however, disprove my opinion that clarification if climate sensitivity depends on water availability for evaporation from the land may be still important.”
It does – the same two reasons that made your Sahara mitigation scheme a spectacular intellectual failure (massive volumes of water required and v.sort residence time) will also do so to ANY OTHER ways of your “potential for AGW mitigation action addressing soil moisture”
So stop wasting everybody’s time, clog the public discussion space with the same dead-end idea and stop, by the sheer volume of your posts, trying to fool a passing reader or AI models – that yours is somehow a viable alternative to the only feasible way of AGW mitigation – reducing the GHG’s concentration.
Now go away or we shall taunt you a second time!
in Re to Piotr, 5 Sep 2025 at 12:39 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838906
Hallo Piotr,
First, I would like to assure you that although your criticism may be often unpleasant, it definitely deserves a thorough consideration and is therefore helpful.
Let me now turn to the rest of your post. It appears that in your opinion, a study directed to clarification how strongly may Earth climate sensitivity depend on water availability for evaporation from the land would have represented a wasted time and effort, because humanity has a negligible influence on land hydrological regimes.
If this is indeed your view, I respectfully disagree therewith.
First, the assumption that humanity has a negligible influence on land hydrological regimes may be incorrect, although your argument by enormous difficulty of land switching from an arid hydrological regime into humid one by artificial irrigation may be valid. It is because it seems to be well possible that the opposite change, namely land switching from a humid hydrological regime into arid one, may be much easier. There already are hints that a such switch can be caused e.g. by forest logging and/or improper agricultural practices promoting soil degradation and erosion.
In other word, no artificial soil drying that would have been comparatively expensive (as the artificial irrigation considered for the opposite switch) seems to be necessary for a “successful” anthropogenic land drainage / desiccation in many regions.
Second, I am afraid that if doubts about practical applicability of supposed research results would have been the sufficient criterion against arranging / starting any specific research, only very few discoveries would have ever happened. In this respect, I think that the difference between a mere assumption that an effect is negligible and a thorough study showing with a decent certainty that the effect indeed IS negligible, is in my opinion quite fundamental.
Greetings
Tomáš
Tomas “ First, I would like to assure you that although your criticism may be often unpleasant, it definitely deserves a thorough consideration and is therefore helpful.”
Save the platitudes – it counts only what you do. And what you do is, whenever even remotely possible, to ignore the criticism and accept only the things that in your mind support your a priori beliefs. By their fruits, not their declarations about their openness to criticism, you shall know them.
in Re to MA Rodger, 2 Sep 2025 at 5:56 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838720
Dear MA,
Thank you very much for your comment. It is an extraordinarily useful feedback for me, because it is a hint why no one clearly replied to my questions addressed to Dr. Schmidt yet.
It appears that as soon as people note the word “water”, their brains automatically add “feedback” and switch to a regime “already known, stop reading”.
Equally as Atomsk’s Sanakan, 28 Aug 2025 at 1:38 PM,
https://www.realclimate.org/index.php/archives/2025/07/the-endangerment-of-the-endangerment-finding/#comment-838493
you are completely right that the influence of global warming on land hydrology is addressed in many studies. This is, however, not what I asked for.
There undoubtedly are many human activities directly affecting land hydrological regimes, without any mediation through carbon dioxide atmospheric concentration and/or through anthropogenic emissions of any other non-condensing greenhouse gas. Examples of such activities can be e.g. landscape drainage, sealing the landscape surface by concrete infrastructure that prevents water infiltration, or soil degradation through improper land use. I ask if (and if so, in which extent) such activities may change climate sensitivity.
If you know a publication dealing with this question, please let me know.
Greetings
Tomáš
TK: It appears that as soon as people note the word “water”, their brains automatically add “feedback” and switch to a regime “already known, stop reading”.
BPL: Speaking of responding in a stereotyped way, you have yet to respond to
1) Locating a time series of the variable you want
2) Accepting that the two analyses I did, using two different water-related variables, showed that the data we have does not support any big role for water aside from the water vapor feedback.
It seems clear to me that you will not accept any analysis which does not fit in with your preconceived hypothesis. Every time we try to get you to test it, or to test it ourselves, you simply ignore it and repeat your hypothesis.
Your hypothesis doesn’t mean a damn thing if there’s no way to test it–or if you reject all the attempts at testing it that have already been done.
in Re to Barton Paul Levenson, 3 Sep 2025 at 8:37 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838791
Hallo Barton Paul,
As regards your variance analysis, you told me that the only variable characterizing water availability for evaporation that you could include was the global irrigated area. If I remember correctly, I objected in this respect that the share of irrigated area may not be representative enough for possible anthropogenic changes in global water availability for evaporation from the land.
I must admit that I cannot remember any other analysis we were discussing about. Please refresh my mind, ideally by a reference where I could learn more about your methods and results.
I must also admit that I am quite sceptical, nevertheless, I cannot remember a discussion of any evidence for or against the relationship between water availability for evaporation from the land and climate sensitivity. As far as I know, all what we discussed so far (your simple model and then the publication by Lague et al,
https://iopscience.iop.org/article/10.1088/1748-9326/acdbe1
dealt with the direct relationship between global mean surface temperature on one hand and the latent heat flux on the other hand. I am not aware of any clue yet if the hypothesized relationship between water availability for evaporation and climate sensitivity may (or may not) exist.
I cannot exclude that dementia already overwhelmed me and that I have simply forgotten the evidence you have presented and that I for this reason still ignore. If so, please be so kind and try to remind me specifically what evidence it was.
I still remember that I have several time attempted to ask if it might be technically feasible to test the hypothesis the hypothesis by extending the modelling approach used by Lague et al, by computing and comparing climate sensitivities for their modelled “desert land” and “swamp land” Earths. Unfortunately, none of the moderators paid an attention to this question yet. So far, other Real Climate readers, with JCM as the sole exception, reject to join me in asking this question.
In this respect, I would like to correct you in the sense that I (still) hope there indeed might be a way how to test the said hypothesis, however, I am neither capable to do it myself, nor to raise an attention / interest of the people who perhaps possess the necessary skills.
Best regards
Tomáš
To Tomas,
Evidently the Zhiyan Zuo et al 2024:
“Importance of soil moisture conservation in mitigating climate change”
https://www.sciencedirect.com/science/article/pii/S209592732400135X
provides a good sense of moisture limitation impacts averaged in the world of MIPs. Holding the moisture parameter to 100cm depth at the mean (impaired) 1980–2014 state reduces global surface air temperature change 0.04C/decade in a future emission scenario. This eliminates 20% of the total warming anticipated under the SSP1-2.6, and 32.9% of the global mean land warming.
This roughly aligns in magnitude with my previous sketches of historical climate destabilization consequences using various model, reanalysis, and data-driven methods.
There can be little dispute that the global cooling effect provided by soil moisture is significant, and even more pronounced where people live. Conservation and remediation of soils are essential mitigation strategies, with “non-climate” co-benefits that are arguably even more important.
Adopting a strategy to conserve and remediate soils introduces several cooling mechanisms, notably through the increase of evapotranspiration, which promotes cloud formation and dynamical normalcy.
The relative neglect of this subject in the academic climate literature is likely rooted in the UNFCCC’s framing of research priorities, as highlighted by Dessler and co. in the Climate Experts’ Review of the DOE Climate Working Group Report. That review notes nine explicit references to the UNFCCC and over 340 citations of IPCC assessment reports, reflecting how governance frameworks set agendas, confer legitimacy, and direct funding streams. This policy-driven demand for evidence strongly steers the trajectory of global research.
“The premise of the United Nations Framework Convention on Climate Change (UNFCCC), which the U.S. signed and ratified in 1992 – and to which the US is still a party – acknowledges that climate change is a collective problem requiring action on behalf of all nations, as no single country can achieve the goals of the UNFCCC on its own. It states on the first page, that “the global nature of climate change calls for the widest possible cooperation by all countries and their participation in an effective and appropriate international response, in accordance with their common but differentiated responsibilities and respective capabilities and their social and economic conditions” (United Nations 1992, 1). Clause 2.a (p.6) of the UNFCCC asserts that “Parties shall adopt national policies and take corresponding measures on the mitigation of climate change, by limiting its anthropogenic emissions of greenhouse gases and protecting and enhancing its greenhouse gas sinks and reservoirs”.”
Dessler, A.E. and R.E. Kopp (Ed.). (2025). Climate Experts’ Review of the DOE Climate
Working Group Report. DOI: to be assigned, URL to be assigned
pgs 407-408
The interesting bit of Zhiyna Zuo et al is the integration of thermodynamic biophysical soil moisture effects into a familiar IPCC-style scenario framework, broadening the scope beyond the conventional which I think is novel. As emphasized by Dessler and co. in their expert review, the existing assessments are focused on gaseous emission, sinks and reservoirs, and by association mainly the biochemical aspects of landscapes such as carbon stick accounting.
in Re to JCM, 3 Sep 2025 at 9:21 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838792
Dear JCM,
Thank you very much for your comment and for the provided reference.
I must, however, admit that I do not fully understand the article by Zhiyan Zuo et al
On one hand, it appears that in the modelling experiments done by the authors, fixing the soil moisture prevented a stronger warming in comparison with the warming observed when soil moisture has been allowed to decrease. This result might be perhaps indeed understood the way that fixing a high soil moisture decreases climate sensitivity towards increasing atmospheric concentration of non-condensing greenhouse gases.
On the other hand, I have not noted a tiniest attempt of the authors to interpret their results as a climate sensitivity change of the selected climate models due to change of their default setting (assuming decreasing soil moisture with rising temperature?) towards a fixed (high) soil moisture.
The complete absence of a such attempt raises my strong doubts if their results indeed could be construed as I originally assumed.
I would therefore highly appreciate a comment on this article (and on my speculative interpretation thereof) from a reader more skilled in climate science or, ideally, by a professional climate scientist.
Greetings
Tomáš
I hope you do find answers for your question; although I caution that it depends on perspective.
My five cents in the context of the article: Climate sensitivity is basically the temperature change caused by a radiative forcing. Forcing agents have been reduced to: carbon dioxide, other well mixed GHG, ozone, stratospheric water vapor, surface albedo, aviation contrails/cirrus, aerosols, and solar variation.
Climate sensitivity is inferred using temperature changes and the sum of various forcings. The net of human caused forcing agents is estimated to be about 2 to 3.5 W/m2 from 1750 to 2019 in the 6th assessment report. https://www.ipcc.ch/report/ar6/wg1/figures/chapter-7/figure-7-6
The convention is straightforward: If net forcing is on the low end (≈2 W/m2), then climate sensitivity must be high to match observed temperature change. If forcing is on the high end (≈3.5 W/m2), then climate sensitivity must be low.
For example, Hansen has argued that aerosol effects have exerted a more negative forcing than midrange estimates, resulting in a low-end net forcing (around 2 W/m2); the argument is that sensitivity must be high to explain observed temperature change because the aerosol effect has caused net forcing to be low.
Sensitivity hinges entirely on forcing estimates. Related to your question, a greater temperature increase for the same net forcing must naturally be interpreted as suggesting higher climate sensitivity.
However, if one explicitly accounts for moisture limitation in the way of a forcing, that increases the magnitude of net forcing term, resulting in lower climate sensitivity to explain temperature change.
In other words, perception of climate sensitivity depends entirely on what you decide is a forcing or not, and its intensity.
It is directly in the summary for policymakers that “Observed warming is driven by emissions from human activities”.
https://www.ipcc.ch/report/ar6/wg1/figures/summary-for-policymakers/figure-spm-2
and so it has already been prescribed that unnatural moisture limitation cannot be a cause of observed warming, because it is not an emission like that of major trace gases or direct water vapor emission https://www.realclimate.org/index.php/archives/2025/07/are-direct-water-vapor-emissions-endangering-anyone/. Any potential effects of profound soil and hydrological deterioration and associated unnatural alteration have to folded into the perception of climate sensitivity itself, rather than recognized as a separate driver. It’s an odd convention, but that’s how the system is structured.
In light of IPCC AR6 lead author Zhiyan Zuo’s novel work, it’s useful to keep in mind the magnitudes involved are 3-4kg/m2 moisture change in the root zone over many decades. This is useful quantitative model output. Zhiyan Zuo contrasts the MIP derivative and counterfactual with a difference in trend 0.05 kg/m2 per year. At risk of getting lost in model land, remember that actual soil moisture change has been an order of magnitude greater than such estimates, a fact which underpins our discussions here. It goes without saying.
One of the paradigms of conservation stewardship is that available moisture is positively related to soil organic matter (SOM).
“Soil Organic Carbon: A Foundational Indicator of Soil Health”
https://extension.missouri.edu/publications/g9071?
It is the impetus for conservation stewardship, “world soils day” public awareness campaigns, and many other initiatives that I discuss here frequently. SOM is estimated to have been depleted 30-70% across many parts of the world – it is one of THE major global issues and must never be minimized.
Empirical work on moisture relation to SOM is traced back to Hudson 1994 https://www.tandfonline.com/doi/abs/10.1080/00224561.1994.12456850?
“Soil organic matter and available water capacity”
And we have available various extensions and literature reviews ongoing of soil health principles and remediation actions
“Effects on Soil Water Holding Capacity and Soil Water Retention Resulting from Soil Health Management Practices Implementation―”
https://www.nrcs.usda.gov/sites/default/files/2022-10/AWC_Effects_on_Soil_Water_Holding_Capacity_and_Retention.pdf
My preference as a rule of thumb is +1% SOM ≈ +20,000 L water per hectare (in the root zone). That equals 2mm water per hectare, or 2 kg/m2 of additional (or lost) soil water. Conservation of such things and abatement of ongoing erosion is certainly achievable with basic and well known soil health management systems. While the scale of global soil deterioration is obviously far more extreme than many have yet to comprehend, i”m afraid it’s balanced equally by extreme undervaluation of real environmental initiatives.
It is obvious to those of us outside that claims suggesting recovery a few mm of soil moisture requires reforesting half the planet are ridiculous, sounding almost daunting. It doesn’t pass basic sniff test and such results almost certainly come from structural miscalculations or limitations in model inputs. This does not reflect poorly on the author; rather, it highlights issues in the framework convention that are reflected in the models themselves. In practice, restoring a few millimeters of soil moisture is achievable through simple, well-established methods, without undermining field productivity. Climate models suggesting otherwise are contrary to reality. Nevertheless, Zuo’s example offers an extremely useful perspective on climate drivers, sensitivity, and model limitations, while also providing a template for situating these discussions within familiar governance paradigms and policy targets.
in Re to JCM, 6 Sep 2025 at 10:59 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838982
Dear JCM,
Many thanks for your explanations.
As the authors of the article have not changed soil humidity, I suppose that it could not be considered as a forcing. If so, fixing a higher soil moisture content can be considered as another intensity of a “combined water feedback” than fixing a lower soil moisture content.
It appears that fixing a higher soil moisture content resulted into lower temperature increase for the same net forcing. In this sense, I think that the study by Zhiyan Zuo et al 2024:
“Importance of soil moisture conservation in mitigating climate change”
https://www.sciencedirect.com/science/article/pii/S209592732400135X
can be indeed considered as a strong hint that higher water availability for evaporation from the land causes a lower sensitivity to the net forcing. It remains unclear why the authors of the article desisted from interpreting their results this way.
Greetings
Tomáš
JCM To Tomas, Evidently the Zhiyan Zuo et al 2024 provides a good sense of moisture limitation impacts averaged in the world of MIPs.
Since Zuo solutions is afforestation of croplands and pastures, and since 1 km2 of forests evaporates MUCH more water than 1 km2 of soil:
– HOW MUCH water will you have to supply and spread over all these newly afforested areas?
– WHERE all this extra water (to keep the soil moisture and for the massive evaporation by the trees) will come from ??? From the already overexploited underground aquifers, piped over 1000s of kms and spread over mlns of km2 ?
And with big chunk of the current agriculture – the low and mid latitude croplands and pastures converted to forests – where would our food come from?
The onus of the answer on all the above is on you, not on UNFCCC.
And then there is a much more fundamental. problem – what you, Tomas, and Zuo propose is to deal with<b< the positive feedback , UNFCCC. prefers dealing with the driver – the latter almost always is more effective for several reasons:
a) A reduction iin GHGs reduces AGW by less GHG warming, the effect that is then strongly amplified by the water cycle feedback. You are intervening already at the level of the feedback, so no such amplification for you.
b) The perturbation time of a one-time CO2 reduction is 100 yrs. The perturbation time of WV in atm. is about a week. I am not sure about the moisture in the top 1 m of soil, but given the large volumes of rain and evaporation – it would be much closer to a week than to a century. Say, generously, it is a year. Which would mean:
– the effect of my on time Co2 reduction is felt for about 100 years afterward (the atm. conc. of CO2 will be lower for that period than would have been otherwise).
– the effect of your intervention disappears very quickly, so you have to REPEAT it every year for 100 years
c) Co2 fluxes are many orders of magnitude smaller than those of water, so the former are MUCH easier/cheaper to alter than the latter.
So now you can see why the body tasked with finding the most realistic (read: cost-effective) ways to mitigate AGW – concentrates on GHG reduction and not on your irrigation schemes, which if ever implemented would come AT THE EXPENSE of reduction the GHG mitigation
Regardless of the Tomas protestations on how he sees the irrigation schemes as a complement, not the competition, of GHG reductions – in the real world which has limited willingness, and therefore resources, to fight AGW – every dollar that goes into your irrigation schemes is one dollar less to go into GHGs reductions.
By the fruits of the actions they advocate you shall know them.
in Re to Piotr, 5 Sep 2025 at 3:50 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838908
Dear Piotr,
As you may take from my post of the same moderation round (of 5 Sep 2025 at 12:20 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838905 ),
I merely ask questions how I can read the article
“Importance of soil moisture conservation in mitigating climate change”
https://www.sciencedirect.com/science/article/pii/S209592732400135X
I have not specifically commented on afforestation as the solution proposed by the authors. I have a feeling that the authors have not studied the asserted positive effect of afforestation on soil moisture conservation themselves. It appears that they rather relied on a few references that they have cited in this respect.
As far as I know, JCM generally promotes “ecosystem conservation” and more specifically focuses on soil quality. I do not know if the inventory of his tools includes afforestation. I, however, somewhat doubt that it includes artificial irrigation.
Greetings
Tomáš
Tomas “I have not specifically commented on afforestation”
Multi-continental scale afforestation of low and mid lat lands was identified as the most promising way by the source brought up by JCM. Hence my question on afforestation were addressed to JCM, the person who used that source as a vindication of his opinions, not to you.
in Re to Piotr,
Hallo Piotr,
My understanding to JCM’s response of 6 Sep 2025 at 10:59 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838982
is that he simply does not consider afforestation proposed by the authors of the article as necessary, if proper agricultural practices manage to keep soil organic matter content sufficienrly high.
I hope that he will correct me if I am wrong.
Greetings
Tomáš
Tomas: “[JCM] simply does not consider afforestation proposed by the authors of the article as necessary,
So you are saying that JCM … rejects the central conclusion/recommendation of the very paper he brought up here to present … as proof of his opinions??? With fronds like these – who need anemones ? ;-)
in Re to Piotr, 11 Sep 2025 at 12:50 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839187
Dear Piotr,
It appears that your objections are mostly based on your belief that the focus of Zhiyan Zuo et al 2024:
“Importance of soil moisture conservation in mitigating climate change”
https://www.sciencedirect.com/science/article/pii/S209592732400135X
was on the study of the relationship between land afforestation on one hand and soil moisture retention (and mitigating climate change this way) on the other hand.
The title of chapter 3.4 of the article does indeed suggest that
“Afforestation can be a nature-based solution for soil moisture conservation”
It appears, however, that this suggestion does not have a direct support in modelling experiments made by the authors and described in other parts of their article. The first paragraph of the chapter 3.4 rather suggests that they rely on results published elsewhere:
“Vegetation plays a crucial role in enhancing soil moisture retention [44], [45], forming the foundation of our hypothesis that afforestation could serve as an optimal nature-based solution for maintaining soil moisture, with the potential to cool global land regions”
The following paragraphs in the right column on page 1336 (the article in .pdf format is publicly available through a button on the website linked above) suggest that the authors based their bold conclusion (that soil moisture preservation can be secured by afforestation in low latitude regions) on
a) an existing correlation between decreasing vegetation cover and decreasing soil moisture, see e.g. the sentence
“When deforestation occurs in regions such as eastern China, central Africa, and northern South America – where the most substantial increase in vegetation is anticipated under the SSP1-2.6 scenario – a significant reduction in soil moisture becomes evident.”
and
b) a hope that under specific future emission scenarios, “land greening” may prevail over “land drying”, see e.g. the paragraph
“Under the SSP1-2.6 scenario, it is anticipated that global land regions will see an increase in vegetation growth during the 2020–2059 period, despite concurrent soil drying (Fig. 4a). This finding suggests that vegetation expansion is not hindered by existing soil moisture deficits.”
On page 1337, the authors conclude that
“The cumulative evidence underscores the viability of adopting afforestation in low and mid-latitudes within the SSP1-2.6 scenario during the 2020–2059 timeframe as a robust and effective nature-based strategy. This approach demonstrates potential feasibility and efficiency in preventing soil from undergoing excessive drying.
By preserving soil moisture levels through afforestation, this nature-based solution holds the potential to support the realization of the Paris Agreement’s objectives and substantially mitigate climate risks.”
This suggestion may sound encouraging, especially in the sense that the proposal does not seem to require any artificial irrigation assumed by you as a necessary condition for a successful afforestation in the respective regions.
I do not wonder, however, that JCM remains cautious and appreciates rather the observations on the relationship between soil moisture preservation and climate stability resulting from the research described in the article than this bold (and potentially overly optimistic) conclusion addressing possible climate change mitigation by afforestation.
Similarly, I do not dare to assess if the conclusion about applicability of the proposed afforestation is as strongly supported as the authors seem to assume. Anyway, I see their results as a potentially important hint supporting my speculation that climate sensitivity might depend on water availability for evaporation from the land. I therefore still see my question to moderators (If a dedicated modelling study, with the aim to clarify how strong this dependence is, could be technically possible) as relevant and potentially important.
Best regards
Tomáš
Tomas Kalisz: “Thus, you (again, as already happened many times before) attempted to redirect the discussion about absence of a basic knowledge (how much a change in availability for evaporation from the land may influence climate sensitivity) to your straw man topic (that “AGW mitigation addressing soil moisture”)
Piotr: You are joking, right? You are attacking me that in my response to the paper titled
Importance of soil moisture conservation in mitigating climate change ” I have addressed what the authors themselves considered THE MOST IMPORTANT part of their paper (so important that they put it in the paper’s TITLE)???
Tomas Kalisz: “ Please note that although the title of the article expressly mentions climate change mitigation, the context in which JCM has cited this article was indeed different”
and what does it tell you about your guru, JCM – that he brings up Zuo’s paper AS IF it supported his and your “anything but GHGs” denier agenda, ONLY TO IGNORE THE CENTRAL argument of Zuo’s paper and in fact, according to you, to actively NEGATE IT: (“TK: [JCM] simply does not consider afforestation proposed by the authors of the article as necessary“?
And what does it tell about YOU , that you not only defend the above JCM’s intellectual dishonesty, but you also ATTACKED me for calling the attention to it, by accusing me discussing the CENTRAL point of the Zuo’s paper, is my [repeated] attempt to redirect the discussion ?
A real-life illustration of the saying : “ A thief [points at the just robbed man]: “Stop this thief!“?
Tomas Kalisz: “ The proposal does not seem to require any artificial irrigation assumed by you as a necessary condition for a successful afforestation
In your head, perhaps, in the real life not, as I already explained to you in the very post to which you are now supposedly “replying”:
====
P. 5 Sep.: Since Zuo solutions is afforestation of croplands and pastures, and since 1 km2 of forests evaporates MUCH more water than 1 km2 of soil:
– HOW MUCH water will you have to supply and spread over all these newly afforested areas?
– WHERE all this extra water (to keep the soil moisture and for the massive evaporation by the trees) will come from ??? From the already overexploited underground aquifers, piped over 1000s of kms and spread over mlns of km2?”
====
And before you disown your argument on afforestation, by lecturing me that talking about afforestation is an attempt to divert from … actual subject of discussion here, my questions APPLY EQUALLY WELL to all non-afforestation methods of increasing evaporation from land:
The more you evaporate, the more water you need to supply to replace that extra evaporation,
So WHERE are the required ^* many thousands of KM^3 of extra water per year, supplied for many decades? centuries (?) are coming from?
—–
^* the volume based on Lague et al. to get a fraction of 0.3K reduction in AGW
in re to Piotr, 13 Sep 2025 at 9:43 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839262 ,
and 13 Sep 2025 at 11:01 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839264
Hallo Piotr,
It appears that you are determined to ignore my objection that the topic of my exchange with JCM was the relationship between water availability for evaporation from the land and climate. It is your choice.
Actually, I missed that the reference to the article Zhiyan Zuo et al 2024:
“Importance of soil moisture conservation in mitigating climate change”
https://www.sciencedirect.com/science/article/pii/S209592732400135X
suggested by JCM as relevant, has been proposed already by MA Rodger on 2 Sep 2025 at 5:56 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838720 .
My thanks for this reference had thus to be directed not only to JCM but also to MA Rodger. I hereby apologize to him for this omission.
As regards the content of Zhiyan Zuo et al 2024, I commented thereon on 12 Sep 2025 at 12:33 PM ,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839213
It does not appear, however, that you have anyhow considered these comments in any of your two posts, so I have nothing else to add at this time.
Best regards
Tomáš
Piotr writes:
“HOW MUCH water will you have to supply and spread over all these newly afforested areas?
WHERE all this extra water (to keep the soil moisture and for the massive evaporation by the trees) will come from?”
Alternative: do more with what we already have, using silicon, aka “rock dust”, aka “enhanced weathering”.
. . . . . . . . . . . .
AI Overview
Silicon can increase soil moisture retention, improving a soil’s ability to hold water and be more available to plants, especially under drought stress. Silicon also forms a physical barrier in plant leaves that reduces water loss through cuticular transpiration. Additionally, silicon itself is used in the construction of certain low-cost soil moisture sensors for agriculture, utilizing its physical and thermal properties to measure water content.
Silicon’s Effects on Soil Moisture
Increased Water Holding Capacity:
Applying silicon, particularly as amorphous silica (ASi), to soils has been shown to significantly increase soil moisture levels.
Improved Soil-Plant-Water Relations:
By improving water holding capacity, silicon can enhance the relationship between soil, plants, and water, making more water available for plant uptake during drying conditions.
Enhanced Water Availability:
Studies have demonstrated that silicate-treated plants have better water use efficiency, suggesting that improved soil moisture retention contributes to this benefit.
Silicon’s Role in Plant Water Stress
Reduced Cuticular Transpiration:
Silicon contributes to the formation of a silica-based layer under the leaf epidermis, which acts as a barrier to reduce water loss.
Decreased Stomatal Conductance:
Silicon deposition can also modify cell wall properties, leading to decreased stomatal conductance and a reduction in water loss through stomata.
Drought Resistance:
These combined effects make silicon a potential strategy for improving plant drought resistance, especially in the face of climate change.
END of AI overview
. . . . . . . . .
sample publication:
https://www.mdpi.com/2223-7747/11/13/1687
Silicon Enhances Plant Vegetative Growth and Soil Water Retention of Soybean (Glycine max) Plants under Water-Limiting Conditions
by Saroj Kumar Sah, Kambham Raja Reddy andJiaxu Li
Plants 2022, 11(13), 1687; https://doi.org/10.3390/plants11131687
Abstract
Silicon has been implicated as a factor affecting the degree of resistance to abiotic stresses in several plant species. However, the role of silicon in soybean (Glycine max) under water-limiting conditions is not yet fully understood. This study was conducted to evaluate the effects of silicon application on the vegetative growth of two soybean cultivars (Asgrow 5332 and Progeny 5333) grown under water-limiting conditions. Silicon was provided by adding silicate to the soil. Water-limiting treatments were imposed on plants at two vegetative growth stages for 20 days by irrigating with a reduced amount of water (66% or 33% of the required water). Silicate application enhanced plant height, leaf area, and total dry weight of soybean plants. Significant increases in root volumes were observed in both the silicate-treated cultivars compared to the control plants under water-limiting conditions (33% irrigation). Net photosynthesis and stomatal conductance were decreased, but the quantum efficiency of photosystem II (Fv’/Fm’) did not change under the same irrigation condition, which indicates photosynthesis downregulation through stomatal limitation. Silicate-treated plants in both cultivars had higher water use efficiency as compared to control plants under water-limiting conditions (irrigated with 66% or 33% of required water). Under water-limiting conditions, the soil moisture content was significantly higher in pots containing silicate than in those without added silicate, suggesting that silicon application improves water holding capacity. Taken together, the results from this study indicate that silicon application can improve the vegetative growth of soybeans under low water conditions by increasing the water use efficiency of plants and enhancing the soil’s ability to retain moisture.
Tomas Kalisz: Actually, I missed that the reference to the article Zhiyan Zuo et al 2024 suggested by JCM as relevant, has been proposed already by MA Rodge
More importantly, you also missed that the conclusions from the same paper were rather different:
– JCM used it as a support for his and yours “anything-but-GHGs” denialism, best encapsulated in the classis JCM’s post blaming the massive destructions of Earth’s ecosystems on climate scientists’ “ artificial fixation and overemphasis [on] a trace gas“
– while MAR – after listing the Zuo’s and 5 other papers, haven’t seem in ANY of them much support for YOUR “significantly changed climate sensitivity”, NOR for JCM’s potential for AGW mitigation by addressing soil moisture (at the expense of GHG reductions):
MAR to Tomas K, 2 Sep:
“ The potential for significantly “changed climate sensitivity” from declining soil moisture and any resulting potential for AGW mitigation action addressing soil moisture is not something I see looming large in the literature“.
If I were to chose, I’d always go with MAR’s integrity and scientific knowledge, instead of your’s and JCM’s.
In addition to my reply of 2 Sep 2025 at 1:40 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838733
to MA Rodger, 2 Sep 2025 at 5:56 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838720
Dear MA,,
On 2 Sep 2025 at 1:40 PM, I asked if you know a publication dealing with the relationship between water availability for evaporation from the land and climate sensitivity.
On 3 Sep 2025 at 9:21 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838792 ,
JCM made me aware that this might be the publication Zhiyan Zuo et al 2024:
“Importance of soil moisture conservation in mitigating climate change”
https://www.sciencedirect.com/science/article/pii/S209592732400135X
cited by you on 2 Sep 2025 at 5:56 AM.
After an exchange with JCM, I agreed to him that the results of modelling experiments carried out by Zuo et al indeed could be understood as a hint that preservation of high soil moisture may keep climate sensitivity low / prevent its increase.
Piotr, however, fiercely opposed this view in a series of comments and construed Zuo et al quite differently. In the last post of this series, on 14 Sep 2025 at 4:20 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839312 ,
he asserts that
“MAR – after listing the Zuo’s and 5 other papers, haven’t seem in ANY of them much support for YOUR “significantly changed climate sensitivity””.
Could you kindly specify in more detail how you read Zuo et al and, particularly, assess if my interpretation of their results proposed in my reply to JCM of 8 Sep 2025 at 3:36 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839053
(that there is the above mentioned hint to the relationship betwwen soil moisture and climate sensitivity) is indeed improper as Piotr seems to suggest?
I am afraid that otherwise, the present dispute between me and Piotr will remain unresolved.
I think that lot of such unresolved disputes significantly devaluates any discussion forum, including Real climate.
Would you be so kind and comment?
Thank you in advance and best regards
Tomáš
Tomas Kalisz:
“ Dear MAR, Could you kindly specify in more detail how you read Zuo et al and, particularly, assess if my interpretation of their results proposed in my reply to JCM of 8 Sep 2025 at 3:36 PM, (that there is the above mentioned hint to the relationship betwwen soil moisture and climate sensitivity) is indeed improper as Piotr seems to suggest? ”
Translation: “Dear MAR. Could you please defend my and JCM claims against Piotr’s critique of them, since neither me nor JCM are capable to do so ourselves? Please, please, pleeeeease!
======= for reference – the original exchange =======
Tomas Kalisz trying to soften MAR with his effusive gratitude (and imply that MAR agrees with JCM):
TK: Actually, I missed that the reference to the article Zhiyan Zuo et al 2024, suggested by JCM as relevant, has been proposed already by MA Rodger on 2 Sep 2025 at 5:56 AM, My thanks for this reference had thus to be directed not only to JCM but also to MA Rodger. I hereby apologize to him for this omission.
me: “You also missed that their conclusions from the same paper (Zuo et al.) were rather different:
– JCM used Zuo as a support for his and Kalisz’s “anything-but-GHGs” denialism, best encapsulated in the classis JCM’s post blaming the massive destructions of Earth’s ecosystems on climate scientists’ “ artificial fixation and overemphasis [on] a trace gas“
– while MAR – after listing the same Zuo paper, and 5 other papers, haven’t seem in ANY of them much support for Kalisz’s “significantly changed climate sensitivity”, NOR for JCM’s potential for AGW mitigation by addressing soil moisture (at the expense of GHG reductions.
=======================
in Re to Piotr, 18 Sep 2025 at 4:31 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839454
Hallo Piotr,
My plea to MA Rodger reads rather as follows:
“Dear MA,
could you review my reply of 2 Sep 2025 at 1:40 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838733
to your post of 2 Sep 2025 at 5:56 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838720
consider the following discussion about the article Zhiyan Zuo et al 2024:
“Importance of soil moisture conservation in mitigating climate change”
https://www.sciencedirect.com/science/article/pii/S209592732400135X
and tell me if you can agree to my opinion that the modelling experiments made by the authors indeed could be construed the way that keeping high soil moisture should keep climate sensitivity low, as supposed by me and JCM?
Or do you agree to Piotr’s opinion that no such reading of the article is possible/justified?
It appears that Piotr suggest that the article deals merely with afforestation as a technique that should keep soil moisture high. He objects that such a proposal is, in fact, a distraction from the efforts to decrease emissions of non-condensing greenhouse gases. He assumes, contrary to the authors of the article, that afforestation necessarily requires artificial irrigation (for which no water resources are available on the necessary giant scale assumed by Piotr).
I rely on your integrity that will allow you considering my arguments despite of the “denialist” label assigned to me by Piotr. I believe that at least for Real Climate readers not involved in this dispute, your interpretation of Zuo et al 2024 might represent a valuable independent view based on present scientific knowledge.
Thank you in advance for your comment.”
Best regards
Tomáš
Tomas Kalisz “Dear Piotr, I can only hope that MA will be willing to read the posts”
IRRELEVANT to the fact that incapable of answering my post – you CHANGED the subject:
Piotr 18 Sep: “Wrong plea. Mr. Kalisz. I was referring to your plea from Sept. 16 ^* – NOT to some OTHER plea you made up after the fact (on Sept. 19) INSTEAD of answering the criticism of the original one. P.S. The lady doth plea too much, methinks.”
Thus, unless MA Rodger invented a time machine -he won’t get you out of the corner you have painted yourself into.
– T. Kalisz: “ Hallo Piotr, My plea to MA Rodger reads rather as follows: “Dear MA, could you review my reply of 2 Sep 2025”
Wrong plea. Mr. Kalisz. I was referring to your plea from Sept. 16 ^* – NOT to some OTHER plea you made up after the fact, INSTEAD of answering the criticism of the original one.
P.S. The lady doth plea too much, methinks.
====
^* T. Kalisz Sept. 16: “ Dear MAR, Could you […] assess if my interpretation of their results proposed in my reply to JCM of 8 Sep 2025 at 3:36 PM is indeed improper as Piotr seems to suggest? ”
– Piotr Sept. 18: “Translation: “Dear MAR. Could you please defend my and JCM claims against Piotr’s critique of them, since neither me nor JCM are capable to do so ourselves? Please, please, pleeeeease!”
=====
in Re to Piotr, 19 Sep 2025 at 3:40 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839513
Dear Piotr,
I can only hope that MA will be willing to read the posts and the article pertaining to a topic that may not be his favourable one. If so, I believe that he will be able to read and understand also my plea himself.
Best regards
Tomáš
Onward and upward
Oops. Link.
A Glimpse of Divinity.
https://midmiocene.wordpress.com/a-glimpse-of-divinity/
Responding to MARodger
https://www.realclimate.org/index.php/archives/2025/08/unforced-variations-aug-2025/comment-page-2/#comment-838487
MA, it is not uncommon for people to “get lost in the details” and conflate things like cause and effect and correlation, because they have been using particular terminology for a long time… the map becomes the country. You seem to be illustrating exactly that, as I suggested previously.
If you do a quick search on EEI, you will find that actual climate scientists say exactly what I am saying. Increasing GMST is an effect of the increase in system energy, like other effects.
And, it’s an average of local temps, so, as I illustrated with my simple example, it tells us nothing directly about any individual local temp.
Now, you mentioned the radiative characteristics correlated with GMST, and this was to be the next point in my discussion. Again, my concern is with terminology and communication; my original comment
“EEI is the problem.
GMST is not.”
was motivated by the language of something like “warming in the pipeline”, where it isn’t completely clear what “warming” means.
Here’s my understanding:
-If we stop increasing CO2 tomorrow, the system will begin to approach a new equilibrium state.
-It is almost certain that the new equilibrium state, where EEI is zero, will have a higher GMST than pre-CO2 increase.
-That higher (stable) GMST is, again, an effect of the increased amount of energy in the system, correlated with the energy state of the troposphere at the altitude where radiant energy can escape to space.
So here’s the question: If we did stop increasing CO2 tomorrow, what would be the best metric for quantifying that approach to equilibrium? GMST, or, EEI (TOA radiation calibrated with OHC measurements)?
And I don’t say don’t measure both; I’m asking which is the most conclusive.
in addition to zebra, 2 Sep 2025 at 6:43 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838723
regarding his reply to MA Rodger, 28 Aug 2025 at 6:47 AM,
https://www.realclimate.org/index.php/archives/2025/08/unforced-variations-aug-2025/comment-page-2/#comment-838487
Dear MA,
As zebra has not addressed my reply of 28 Aug 2025 at 3:54 PM,
https://www.realclimate.org/index.php/archives/2025/08/unforced-variations-aug-2025/comment-page-2/#comment-838497
to his post of 26 Aug 2025 at 6:33 AM,
https://www.realclimate.org/index.php/archives/2025/08/unforced-variations-aug-2025/comment-page-2/#comment-838344
yet,
could you perhaps look also on that and consider also replying to my additional questions asked on 26 Aug 2025 at 5:56 PM,
https://www.realclimate.org/index.php/archives/2025/08/unforced-variations-aug-2025/comment-page-2/#comment-838368 ?
Specifically, I asked if I understood your explanations of 23 Aug 2025 at 12:00 PM,
https://www.realclimate.org/index.php/archives/2025/08/unforced-variations-aug-2025/comment-page-2/#comment-838151
correctly that
1) at the “net zero”, the 9% EEI share (that presently dissolves ice and/or warms the land and the atmosphere) will quickly drop to zero, and
2) it does mean that afterwards, only the (deep) ocean will continue to warm?
I suppose that if so, the reply to the present question asked by zebra (What will happen with GMST and EEI when we achieve the net zero?) might have been comprised in my further question of 26 Aug 2025 at 5:56 PM, namely:
“Do the studies cited by you indeed suggest that at as soon as the rise of the atmospheric GHG forcing stops, so will do also Earth surface warming, because although EEI will be still positive, basically all this excess energy absorbed by the Earth will be transported into deeper layers of the ocean and therefore will not measurably warm the surface anymore?”
Thank you in advance for the respective comments and best regards
Tomáš
Tomáš Kalisz 2 Sep 2025 at 3:23 PM “this excess energy absorbed by the Earth will be transported into deeper layers of the ocean and therefore will not measurably warm the surface anymore?” is incorrect physics (and you know it but your mind was elsewhere). Ponder it. It is not the Heat going into the deep (nor thermocline below ~450 m) ocean that can affect surface, the GMST, SST, but only the Volume Rate of the water going down on decadal-century time scales. The temperature of the water descending is irrelevant on decadal-century time scales.
As the ocean equilibriates over 2,000 years (85% at 400 years is my understanding) there is a steady (not unchanging but Steadily changing) effect on GMST. Aside from ENSO heat, which I recall at 0-350 m, the ocean always affects the GMST by altering the rate at which it moves its colder, deeper water to the surface (ocean is 3.5 degrees) and NOT by moving heat into the ocean “instead”. Volume going down deep must be matched by deep volume coming up, that’s what does it.
I’ve no opinion on whatever the debate-argument is here (because of little personal things, I’ve no time to contribute or annoy because winter is approaching very fast and I haven’t done my Chores).
in Re to Barry E Finch, 10 Sep 2025 at 10:10 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839118
Dear Barry,
Many thanks for your feedback.
I do not insist that my understanding to interpretation of the article cited by MA Rodger is correct, although it appears that MA agreed thereto and that it is in accordance with IPPC AR6.
I understand that changes in the intensity of ocean vertical mixing must influence Earth surface temperature. So far, however, I supposed that these changes may be accompanied by a change in the overall ocean heat content and that this change may not be limited on a certain surface layer only. In this sense, I thought that these changes can be described also as changes in “heat transport into ocean” (or therefrom).
I am looking forward for a more detailed explanation of your objections as soon as you manage all your pending tasks.
Best regards
Tomáš
zebra,
So in your understanding, not only did I “get lost in the details,” I additionally “conflate things like cause and effect and correlation.”
Beyond those unsupported assertions (which wouldn’t be at all helpful for an actual lost soul), the first part of your comment is also unhelpful as you are simply repeating your previous argument with no reference to my offered counter-argument. The one addition you present is that there are apparently some unnamed “actual climate scientists (that) say exactly what (you zebra are) saying” somewhere in some undisclosed context or other.
As for the latter part of your comment, I will have to put my pedant’s hat on.
Here are my problems understanding the presentation of your understanding which you seemingly present to make “completely clear what “warming” means,” an objective which I find somewhat surprising.
Whatever, perhaps you could clarify the following ambiguity.
-If we stop increasing CO2 tomorrow, the system will begin to approach a new equilibrium state.
I’m not sure what you mean by “we stop increasing CO2.” You probably mean ‘cumulative CO2 emissions’ but that would make it a far-too-awkward description. So perhaps it is ‘atmospheric CO2 levels’. But are you then meaning that tomorrow would stop increasing atmospheric CO2 which would then remain constant while “a new equilibrium state” arrives? Or will they be dropping as they would under net zero conditions?
-It is almost certain that the new equilibrium state, where EEI is zero, will have a higher GMST than pre-CO2 increase.
I struggle with what you mean by “pre-CO2 increase.” Logically it would mean ‘pre-industrial CO2 levels’. But then I again struggle with your “It is almost certain that the new equilibrium state … will have a higher GMST” because, with atmospheric CO2 levels markedly increased since ‘pre-industrial’, how would it not be “a higher GMST” at equilibrium This is surely entirely certain
-That higher (stable) GMST is, again, an effect of the increased amount of energy in the system, correlated with the energy state of the troposphere at the altitude where radiant energy can escape to space.
I do not see why the “higher GMST” is now become the “higher (stable) GMST” or the use of the word “again” which seems to be indicating some re-establishing of the “effect of the increased amount of energy in the system.” But “again” may otherwise be indicating simply that you are repeating what you said earlier.
I would agree that the troposphere temperature (which you describe as “energy state of the troposphere” to dodge using the word “temperature”) is a better metric for the level of OLR (which is directly impacted by ΔF under AGW) as OLR is restored through an increase in tropospheric temperature. But I struggle with what this “temperature/energy state of the troposphere” is being seen as “correlated with.” GMST or ∑EEI? Is this intentionally ambiguous? It may be you are here setting up the question that follows but this is also supposed to be an account of your understanding.
So here’s the question: If we did stop increasing CO2 tomorrow, what would be the best metric for quantifying that approach to equilibrium? GMST, or, EEI (TOA radiation calibrated with OHC measurements)?
And I don’t say don’t measure both; I’m asking which is the most conclusive.
I don’t know what you intend to mean by “…most conclusive” and I struggle entirely to grasp what you mean by “TOA radiation calibrated with OHC measurements.” And I’m not sure what you mean by “quantifying that approach to equilibrium.”
I could ignore all that pedantry and simply answer that question without you explaining this meaty serving of ambiguity. I could even attempt to explain what I see as the nub of your reason for this second part of your comment, and demonstrate why it is wrong.
But I feel this is a hole you have dug for yourself and you presumably have the shovel to dig yourself out. That way I won’t suffer further accusations of “get(ting) lost in the details.”
MA,
If you understand the nub of my reason for this part of my comment, then how have I “dug a hole for myself” ??????? I don’t mind being wrong; that’s how we learn, which is the point of an actual scientific discussion.
But it sounds like you want to have more details to get lost in. For a well-written discussion of this topic, I suggest:
https://www.researchgate.net/publication/292188056_An_imperative_to_monitor_Earth%27s_energy_imbalance
https://iopscience.iop.org/article/10.1088/2752-5295/ac6f74/pdf
The second one is shorter.
in Re to zebra, 7 Sep 2025 at 2:49 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839001
and MA Rodger, 7 Sep 2025 at 6:35 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838988
Dear Sirs,
I must admit that your dispute runs on a level that I am not able to follow / grasp. Could you perhaps try to address the specific questions I asked on 2 Sep 2025 at 3:23 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838739
and/or in my post preceding it in this thread?
Thank you very much in advance and best regards
Tomáš
Tomáš Kalisz,
I was mindful of your questioning (which you originally set out in August UV thread) but other responses have been grabbing my attention.
(1) Of the things presently warmed by EEI, I would reckon net zero would quickly see the atmosphere, pretty-much most of the land (it being well insulated) and the ocean mixed layer stabalise temperature-wise. That would leave the ice, perhaps more the polar ice (which is a lot more bulky per land area) and the deep oceans as the sole recipients of any remaining EEI. Note with the polar ice – if Greenlamd melts down, the process would continue for several millennia.
(2) Deep oceans and polar ice.
The final question – Yes.
In Re to MA Rodger, 8 Sep 2025 at 11:43 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839043
Dear MA,
Thank you very much for your clarification.
I must admit that it changed the picture that I have had in my mind. So far, I assumed that Earth surface warming, observable as global mean surface temperature (GMST) rise, will continue until the Earh energy imbalance (EEI) falls to zero.
In fact, the picture is more structured:
As soon as the “net zero” is reached and the atmospheric concentration of non-condensing greenhouse gases does not increase anymore, so will also the GMST.
It is because the persisting EEI is further transformed solely into deep ocean heating and ice thawing, which both have a negligible influence on GMST.
It is, further, my understanding that (the deep ocean heating as well as land ice thawing) both contribute to ocean volume increase. Although the Earth warming will continue until the EEI falls to zero, the absorbed heat will not increase the GMST anymore but solely the global sea level.
I checked the Summary for Policy Makers (SPM) of the last IPCC report
https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_SPM.pdf
It appears that this message is implicitly contained therein (especially in part D, pages 27-31). No explicit link between various emission scenarios and EEI on one hand and temporal GMST and sea level changes on the other hand seems to be provided yet.
Therefore, I see your explanation very instructive. I think that it could be helpful if next editions of the IPCC reports would have amended their SPMs with a similar explanation in a suitable format (graphic?).
Best regards
Tomáš
Tomáš Kalisz
You rightly link the post-net-zero EEI with global SLR which is something that does sit in the “committed” zone (whatever that means).
I do get annoyed by SLR studies concentrating on the SLR appearing by 2100 while ignoring the multi-century SLR. The message given by AR5 Figure 13.14 was pretty clear (although the annotation could have been written on the graphic – Multi-millennial sea level rise commitment (left) & 2ky = AD4000 (right) per ºC from (a/f) ocean warming, (b/g) mountain glaciers, (c/h) Greenland and (d/i) Antarctic ice sheets. (e/j) Global Total).
That would suggest that at +1.5ºC AGW, we have stoked up 4m of “committed” SLR.
AR6 was not so clear with its Section 9.6.3.5 ‘Multi-century and Multi-millennial Sea Level Rise’ in Chapter 9 which talked of SLR higher than the AR5 estimates.
It does cover a few studies looking at how to reverse the SLR or at least head-off the long-term “commitment”, (which presumably would appear as a set of ‘scenarios’ making it a good way to make a complicated situation doubly-complicated).
Sure, them there SLR error bars may be big, but I’d like to see something (or some statement) put boldly, perhaps along the lines of the graphics of Clark et al (2018) ‘Sea-Level Commitment as a Gauge for Climate Policy’.
in Re to MA Rodger, 11 Sep 2025 at 9:12 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839174
Dear MA,
Thank you once again for your additional feedback. I think that your explanations basically responded also to previous comments by zebra and/or Nigel.
There is, however, a comment by Barry E. Finch, of 10 Sep 2025 at 10:10 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839118
wherein he seems to disagree with the summary that I proposed.
I asked him today, 12 Sep 2025 at 5:19 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839226
if he could provide a more specific explanation of his objections.
Let us wait therefor.
Best regards
Tomáš
Zebra: It is depressing, isn’t it, how even the most obvious points can be distorted on behalf of individual preferences. Being polite doesn’t make anybody right. And being profuse (in length or aggrandizement) even less so.
zebra,
Thank you for providing your missing references (perhaps also with a nod togoogle!!)
The first of these which you consider ‘the longer one’ (although the more recent von Schuckmann et al (2023) is even longer) is von Schuckmann et al (2016) ‘An imperative to monitor Earth’s energy imbalance’ describes EEI as “a fundamental quantity defining the rate of anthropogenic global warming” and one requiring more accurate measurement to be useful. This hoped-for usefulness is set against the limitation of GMST as a measurement because natural wobbles make GMST unuseful as a robust means of tracking AGW at a decadal level. On a multi-decadal level, GMST is absolutely fine. And unlike EEI, GMST does have a far longer (and thus far more useful) record of measured data.
(The data used in their Fig. 3 is model data from CMIP5 models of pre-industrial-climate runs spanning a combined 14,000 years. Presumably if 30y averages were used instead of 10y, both EEI & GMST versions would be very-much alike.)
The second of these references which you consider ‘the shorter one’ is Trenberth & Cheng (2022) ‘A perspective on climate change from Earth’s energy imbalance’ (Note Trenberth is a co-author of the longer paper). In terms of providing some support in an EEI v GMST contest, it should be noted that Trenberth & Cheng do ask the question “How well is EEI known and does it matter?” suggesting there is some doubt to negotiate. And in answering this question, the primacy of retained surface energy (thus ‘surface temperature’) is evident. (I’m not sure how to interpret the statement “heat might be moved to where it can be purged from the Earth via radiation to limit warming”.)
All in all, shoving quotes here saying the likes of “The EEI is arguably the most important metric related to climate change.” or “EEI represents a fundamental quantity defining the rate of anthropogenic global warming.” does ignore surrounding text which greatly reduce this quoted ‘importance’ or ‘fundamental’ nature of EEI.
…
So, did I say anywhere that I understood the nub of your reason for the second part of your earlier comment?
Did I?
No I did not!!
I went only so far as to suggest I had understanding of “what I see as the nub of your reason for this second part of your comment.” Whether I am right in that view is not yet determined. And that continued doubt would make negotiating the meaning of the vague and unfathomable descriptions in your comment (those flagged in my previous comment); that continued doubt thus creates a nightmare for any honest responder.
So firstly, I would be pleased if you don’t put words in my mouth.
And secondly, if you want to continue this interchange (which you describe as a discussion elsewhare), I suggest it is you who requires to dig it out of the hole you dug for it.
MA,
To avoid putting words in your mouth, here’s a direct quote from
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839043
“Of the things presently warmed by EEI, I would reckon net zero would quickly see the atmosphere, pretty-much most of the land (it being well insulated) and the ocean mixed layer stabalise temperature-wise.”
If this were correct, it would definitely answer my question:
“So here’s the question: If we did stop increasing CO2 tomorrow, what would be the best metric for quantifying that approach to equilibrium? GMST, or, EEI?”.
If GMST is stable, then it would obviously be useless in tracking the rate at which EEI is declining.
Any thoughts?
The changes in energy in the earths system are presumably the fundamental thing, but the graph showing increased heat energy content in the oceans isn’t a whole lot of practical value. So the same would apply for tracking EEI in detail. In comparison the GMST records and projections tell us things in degrees C and this gives us information on how survivable the world will be and how much air conditioning will be needed and makes it possible to calculate rates of ice melt. So I’m not sure where Zebra is really going. It just seems like an academic exercise.
It seems to me that James Hansen has good clarifications of his arguments for a higher climate sensitivity (4,5 degrees C for a doubling of tropospheric CO2 – compared to preindustrial level 280 ppmv) than estimated by the IPCC (3,0 degrees C) in this conversation: https://m.youtube.com/watch?v=w5jShXBD6ck . It would be enlightening to read here a summary of the main arguments for the IPCC estimate (or something in between?) and how then to explain the acclereation of global heating since the 1970’s and especially in the last decade and furthermore in the last couple of years.
Why does the IPCC remain silent on this subject? And silent when confronted with the results in the paper from Rahmstorf and Foster https://www.researchsquare.com/article/rs-6079807/v1 ? If it’s for political-tactical reasons (which I hope it isn’t) that would be very dangerous for the scientific reliability of the panel and risk unvoluntarily contributing to the trumpist-putinist etc. authoritarian/neofascist efforts towards undermining freedom of speech and democracy by falsifying truthseeking into the outcome of completely subjective opining and flat out lies from oligarchs/rulers/dictators and their propagandamachines.
I’m glad that the moderators here are trying to reduce the trolling from climate ignorance propagators, because what we need is serious enlightenment from scientific researchers about their results and their discussions concerning the development of the global heating crisis. Then we will be better equipped to discuss how to confront the crisis politically.
The rapid development of the global heating crisis is in my view a very central cause of the authoritarian turn of opinions and politics we are witnessing now. Beause when it becomes clear that the hitherto dominant “lukewarm”/greenwashing policy hasn’t been able neither to reduce the fossil fuel consumption by just a tiny amount nor even to just level it out, then it inevitable that higher political tensions will result. Simply because very clear short-sighted economic interests can’t uphold their until now rather undisturbed ideology of “the american way of life”: limitless growth in profits by exponentially growing consumption, when growing proportions of mankind are suffering from the rapidly growing risks and damages and overall reduced quality of life resulting from global heating. The denial then has to be reinforced when the interests behind it will not give in (and obviously they won’t, even “progessive” oligarchs like Bill Gates decline to stand openly up to the Musks, the Thiels, the Kochs etc., they just fade away. The reason being their “social” environment and “economic” dogmas), therefore the attacks on science grow more direct and brutal.
It can’t be underlined enough how much liberalist-common economic dogmatism – the dogmas of the inevitability of endless exponential growth and of a growing income gap between rich and poor (“reaganomics”/pretence of “trickle down”…) upheld also by the Democrats and centrists in Europe etc.) – is the main reason why the efforts to reduce and stop our still growing dependence on fossil fuels are stalling or rather: being stalled. See https://mahb.stanford.edu/wp-content/uploads/2021/07/The_appallingly_bad_neoclassical_economics_of_clim-1.pdf .
The problem with fossil fuels is the illusion of a “magic” energy density which they present. You have to understand quite a lot of geology, biology, physics, paleoclimatology etc. to understand why it took over 23 tonnes of plant matter (foraminifera, grasses etc.) to produce each and every litre of petrol you pump into your tank: “Jeff Dukes, from the Carnegie Institution of Washington, came up with this astonishing figure while studying how efficiently fossil fuels store sunshine as energy. “Fossil fuels developed from ancient deposits of organic material, and thus can be thought of as a vast store of solar energy,” Dukes says. Plants use photosynthesis to turn the sun’s energy into carbon, which is then converted into gas, oil or coal (known in the coal industry as buried sunshine). Over millions of years the plant matter, trapped in peat swamps or as sediments on the sea floor or lake beds, is converted by heat and pressure to form fossil fuels.
It turns out that this process is a very inefficient one, as Duke discovered when he used existing data to estimate how much carbon was lost at each stage. Only 9% of the carbon in the original plants makes it to coal, while just a tiny proportion – 1/10,750 – remains in oil or gas.” https://plus.maths.org/content/burning-buried-sunshine . Se Jeff Dukes’ paper here: https://core.ac.uk/download/pdf/5212176.pdf .
This is of course not understandable if you – like around 30 pct. of US citizens – firmly believe that God created the earth and it’s life forms just six thousand years ago. Even if you don’t believe this, it’s not so easy to understand why the fossil fuels in more than one way (both concerning the climate and the general ecological sustainability of our society/our overconsumption of resources) must be seen as *an ecological dead end that mankind is about to get itself trapped into*. But nonetheless we have to try to get this message across.
The Cassandras – the bearers of unpleasant news and inconvenient truths – will never be popular. But this problem is enormously enhanced, when you have to understand rather complicated science to accept the message. This circumstance makes the job very easy for demagogues, at least up to a certain point. Exactly this is what we are up against with the Trumps, Musks, Putins, Kochs etc. But we urgently have to understand that we can’t avoid this by spreading illusions about how easy it will be to continue the endless growth and “american way of life” while at the same time reducing our consumption of fossil fuels. Unfortunately that error is exactly what most self-proclaimed “climate aware” mainstream politicians have been and still are comitting. They won’t even discuss James Hansen’s carbon fee and dividend, *because they know that this inevitably will bring political confrontation with the oili-/oligarchs. But as the events clearly show: *this confrontation is happening regardless*, it’s already in full swing! Why not, then, take the confrontation over a reasonable political idea, one that will effectively get the inevitable transition away from fossil fuels going?
Karsten V. Johansen: Accusing climate scientists of “contributing to the trumpist-putinist etc. authoritarian/neofascist efforts towards undermining freedom of speech and democracy by falsifying truthseeking into the outcome of completely subjective opining and flat out lies from oligarchs/rulers/dictators and their propagandamachines
If it walks like a duck, quacks like a duck, and takes to water like a duck – then he is ..Darma Darmah Dharma Poor Peru Philly Compliciated Complicius Sabine Ned Kelly .Pedro Prieto Dharma, Escobar Principle ? .
Piotr: We are mercifully free of them. Please take a deep breath and move on.
You outed KVJ by extracting that vital quote. He has no clue about the IPCC, its history, how it works, its mandate, etc. He is guilty of BS, but putting that front and center allows him to redirect us to the pit run by monied interests who want us fighting with each other.
In reviewing what I wrote, I realize I should have held my pixels before I read the whole thing (which, when it gets in the weeds, I am reluctant to do) and as I do too often, exaggerate one ‘side’ or t’other. But on the whole, nitpicking arguments between people who are deeply worried about the serious fix we’re in (extinction wise, all too likely, at the very least a severe trimming) about the levels of danger are a distraction when there are real monsters in town. However, it is a matter for celebration that these more honest arguments are now given room to breathe.
My apologies for exceeding my self assigned remit.
Nigel and Karsten: You both miss the point. The IPCC does not do original research. It is a meeting of multiple parties, based on consensus. It summarizes existing science (what, I think, in other contexts is labeled meta-analysis) and invites all parties, science, government, and industry, into agreement. It’s remit is limited. Assigning authority to a periodic summary of scientific work is a distraction, ably exploited by all parties. In between IPCC reports (which are backward rather than forward looking, which makes their work remarkably excellent given the constraints under which they operate), reality gives us more than plentiful evidence that this is a conservative point of view.
It is sad that those who consider that the IPCC understates the case (which, by its remit, it is required to do) use it as a platform to enable those who deny reality altogether.
—
different topic: I hope that Gavin will continue to deny the sock puppets and AI/ChapGPT/etc. ‘influencers’ a platform to distract from the point of these arguments here on RealClimate. RC is worthy of a better effort.
Because I ask for arguments concerning the latest critique of the IPCC from James Hansen, Stefan Rahmstorf et al., you say i know nothing about the IPCC?
Is that really all you have to say in response to their critique? That they “don’t have a clue” about the IPCC? Your way of arguing here is down on the level of Trump, Putin and all their climate denying oligarchs, bots etc. It’s sectarian and anti-scientific at least. Why so angry?
I repeat my questions: “It seems to me that James Hansen has good clarifications of his arguments for a higher climate sensitivity (4,5 degrees C for a doubling of tropospheric CO2 – compared to preindustrial level 280 ppmv) than estimated by the IPCC (3,0 degrees C) in this conversation: https://m.youtube.com/watch?v=w5jShXBD6ck . It would be enlightening to read here a summary of the main arguments for the IPCC estimate (or something in between?) and how then to explain the acceleration of global heating since the 1970’s and especially in the last decade and furthermore in the last couple of years.
Why does the IPCC remain silent on this subject? And silent when confronted with the results in the paper from Rahmstorf and Foster https://www.researchsquare.com/article/rs-6079807/v1 ?”
Because I ask for arguments concerning the latest critique of the IPCC from James Hansen, Stefan Rahmstorf et al., you say i know nothing about the IPCC?
Is that really all you have to say in response to their critique? That they “don’t have a clue” about the IPCC? If I said something wrong, why not point out what that was? I’m norwegian and no native english speaker so you have to pardon my grammar. But your way of “arguing” here is really down on the level of Trump, Putin and all their climate denying oligarchs, bots etc. It’s sectarian and anti-scientific at least. Why so angry? Why trash me as if I was a sworn enemy? Because I dare to mention that the IPCC so far has been silent concerning the arguments from Hansen et al.? If someone from the IPCC in any way have put forward arguments against Hansens estimate of climate sensitivity, could someone please show me where? Maybe it’s my fault, but I really haven’t been able to find any. Maybe my critical remarks about the silence from the IPCC were too sharp. But I really hope for the sake of the climate, that they would be more open to the discussions – like Gavin Schmidt has been here. The last meetings of the IPCC have been dominated by fossil fuel lobbyists etc., as reported in The Guardian fx. and criticized from many non-fossil NGOs. It seems to me to be a dangerous development. It’s no accident that this has been criticized among others by the exellent science historian Naomi Oreskes. https://m.youtube.com/watch?v=UZk4Xjn6tEY&pp=ygUsbmFvbWkgb3Jlc2tlcyBjcml0aXF1ZSBvZiB0aGUgSVBDQyBjb25zZW5zdXPSBwkJsgkBhyohjO8%3D
https://m.youtube.com/watch?v=DbTHJWev0nQ&t=183s&pp=2AG3AZACAcoFH25hb21pIG9yZXNrZXMgd2h5IHRydXN0IHNjaWVuY2U%3D
Are you angry at me because I am in favour of Hansen’s idea called carbon fee and dividend? Why shouldn’t it be allowed to discuss that subject here? What kind of political censorship is that? I’m no enemy of yours, I am against any climate science denialism. But I see the vested interests behind it. The oligarchs. I’m just of a different opion concerning some policy themes.
Is it really impertinent to mention here the critique from Steve Keen concerning the gross mainstream neoclassical economic underestimation of the proportions of the climate crisis, f.ex. here: https://mahb.stanford.edu/wp-content/uploads/2021/07/The_appallingly_bad_neoclassical_economics_of_clim-1.pdf ?
Well then could you just please tell poor idiots like me why? Or is that below you? I seem to have stepped into a hornet’s nest as we say in norwegian (pardon me if you don’t have that expression in the US). But as I said, I really don’t believe in suppressing real, well argued differences differences of opinion concerning how to counter the ongoing attempts from fossil fuel interests behind Trump etc. to cancel the whole climate movement. If that’s forbidden here, then I seem to have misunderstood what the purpose of this site is. If it’s the spreading of cancel culture, I beg to disagree, and it seems to me that the moderators do too. I aggree with Gandhi: we have to grasp the center of our differences in opinion, grasp the core of the conflict.
KVJ, my impression was that Susan was angry with you for criticising the IPCC, and insinuating they have been corrupted by political interests. I also get suspicious when people criticise the IPCC, and you weren’t very specific, and this raises suspicions. Most warmists get protective of the IPCC, given the nonsense they have had to endure from the denialists.
That said I think there is an element of truth in what you say. Politicians or their bureaucrats have to sign off IPCC the summary for policy makers and the language has been watered down to appear to downplay the climate threat and level of certainty over various issues. Its believed this is due to trying to appease oil exporting countries, to get them to sign off the document.
However my understanding is this process hasn’t changed or compromised the numerical data in the summary, and that is the most important content. And politicians don’t sign off the main technical report. There is just no evidence that technical report is corrupted. And if the numerical data in the technical report conflicted with the summary for policy makers, I think we would know about it quickly enough.
Regarding James Hansen and his claims about high climate sensitivity made recently and the IPCC views on climate sensitivity and. To my knowledge the IPCC don’t generally comment on new studies as they happen. They evaluate everything for several years and when their reports are released ‘ they update the conclusions on various issues such as climate sensitivity. If they find Hansen persuasive perhaps they will update things accordingly in the next IPCC report.
Personally I find Hansen quite impressive, but his test for whether climate sensitivity is high included this years global temperatures remaining consistently high, to the end of the year but they have generally been falling. MAR has written posts on this you might have seen. But even medium climate sensitivity is quite worrying enough so I dont fixate too much on the exact numbers.
in Re to Karsten V. Johansen, 3 Sep 2025 at 11:15 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838801
and 3 Sep 2025 at 11:38 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838804
Hallo Karsten,
Thank you for your feedback. In Czech, there is also a similar expression as in Norwegian, namely to “step into wasp’s nest”, and as far as I know it reads exactly the same in German, too.
I hope, however, that your situation is not as precarious as in the common experience of European nations with certain insect biota mirrored in our languages across the continent.
I definitely cannot speak for IPPC about their relationship with James Hansen, however, it is my feeling that the main argument for the climate models with medium climate sensitivity is their better fit with historical climate data, whereas the main argument for the “hot” models is their better fit with the recent climate developments.
As I learned that climate sensitivity is not a kind of natural constant with a fixed value, it is theoretically possible that this contradiction could be explained if the value of climate sensitivity increased during anthropocene. Interestingly, it appears that this possibility is not being considered in disputes between “hansenites” and mainstream climate scientists, although there perhaps might be physical mechanism enabling such a change.
It appears that there are no modelling studies yet, clarifying if (and if so, how strongly) may climate sensitivity depend on land hydrological regimes. These regimes might have been strongly perturbed by various human activities. There are some hints that the present intensity of the respective anthropogenic disruptions may be even higher than it has been ever before, nevertheless, it appears that the present level of knowledge in this respect is still much lower e.g. in comparison with historical reconstructions of Earth surface temperature.
This is my subjective picture of the present climate science as I derived it from discussions on this forum. I repeatedly ask the moderators for a comment if the possibility of that “anthropogenic climate sensitivity drift” could be studied by available climate models, and hope that earlier or later, someone provides feedback.
Greetings
Tomáš
Nigel. Setting aside frustrations and feelings, we need to remember that the IPCC is, in fact, a political organization. It doesn’t do original research. It works by consensus. It requires buy-in from governments and industries. It’s surprising how much factual material it is able to present, but by its very nature it is conservative, behind the times, and lacks an enforcement mechanism.
This has hampered its usefulness, a problem problem which has increased. The only thing which can enforce the truth is nature itself. Science does a goodish job of understanding and describing reality, but if the law and government prefer to run on lies, profit, and greed, there’s not a whole lot we can do about it, except continue to point out that lies, profit and greed do not serve humanity well, particularly when ginned up by hate and victim blaming.
I apologize, again, for my tone and bias in my earliest response here.
bj.c: “I think you are taking that out of context, Piotr.
So … you are reading KJV ripping into IPCC scientists for “remaining silent” , insinuates that this silence is self-serving (“political-tactical reasons”), and for them the IPCC scientists are willing to risk ” contributing to the trumpist-putinist etc. authoritarian/neofascist efforts towards undermining freedom of speech and democracy by falsifying truthseeking into the outcome of completely subjective opining and flat out lies from oligarchs/rulers/dictators and their propagandamachines“.
and understand? portray? this as:
bj.chippindale: “ KVJ seems to want a discussion of the differences between the IPCC expectations, reality, and the expectations of James Hansen” .
Hmm.
KV Johansen: “ Because I ask for arguments concerning the latest critique of the IPCC from James Hansen, Stefan Rahmstorf et al.,
No, because you have insinuated that IPCC scientists for “remain silent” for self-serving (“political-tactical”) reasons”, and for that they are willing to risk ” contributing to the trumpist-putinist etc. authoritarian/neofascist efforts ..
To which insinuation you provided ZERO proof – no quotes from Putin or Trump justifying their pro-fossil decisions with the IPCC findings.
Contrast this with . yourself – your posts have been complimented by the RC resident climate change deniers – and used YOUR point post as a jumping point to advance his denialist narratives – how great are fossil fuels ( “allowed modern civilization to be enjoyed by billions of people who would not even be alive without them.”), how the attempts to limit our CO2 emissions via carbon tax are mistaken and how Trump is innocent – claiming that Trump’s actions are “irrelevant to the world-wide CO2 problem”.
Wouldn’t this mean that it is YOU, Karsten V. Johansen, who not only “has risked” but ALREADY CONTRIBUTED “ to the trumpist-putinist etc. authoritarian/neofascist efforts towards undermining freedom of speech and democracy by falsifying truthseeking into the outcome of completely subjective opining and flat out lies from oligarchs/rulers/dictators and their propagandamachines“?
Susan Anderson says @5 Sep 2025 at 10:57 AM
You said: ” the IPCC is, in fact, a political organization. It doesn’t do original research……”
Yes I suppose you could call the IPCC a political organisation, at least to the extent that its created by governments and they gave it a mandate to do certain things namely to determine what’s happening with the climate by looking at all available research. Of course its not staffed with politicians or public servants, but rather volunteer scientists with varied employment backgrounds. So political only to an extent. But I cant see a better alternative to the IPCC, and I think the IPCC is pretty good and so are its reports.
I realise The IPCC doesn’t do original research and neither would I expect it to. It’s an assessment mechanism.
However although you’re right the IPCC needs buy in form governments we need to be vigilant if that buy in is not leading to corruption of its scientific findings. I gave my views on the extent of where there may be a problem and enough clues to easily google the details. I think there’s been a problem but not of huge magnitude. I agree entirely with your sentiment that its remarkable how much factual material is there and I am happy its generally quite reliable.
The IPCCs alleged scientific conservatism or reticence does not seem to be generated by political interference. It appears that science in general is a little bit conservative / reticent and the IPCC just follows this. This doesn’t worry me because :
1) science is conservative to ensure it isn’t constantly making bold claims and having to then admit error and walk these back, which would risk undermining public confidence in science badly. It already has enough problems in this regard without making it worse and
2) I dont believe the IPCC has been excessively or unusually conservative at least not recently. It may have been in the first couple of reports. Read the fine print and it now has warming projections potentially hitting 10 degrees c ( worse case) after three centuries if we continue with BAU. The IPCC also now recognise 2m SLR is possible by the end of this century. Does any of that sound excessively conservative to you? It doesn’t to me, Fortunately we have likely already stopped an outcome quite that bad but we are still not nearly doing enough.
If the public don’t find the content of the last couple of IPCC reports very concerning and worrying I’m not sure when they would. I doubt that if projections were a degree or two higher or the IPCC announced climate sensitivity is high that it would make much difference to the public.
You said “Science does a goodish job of understanding and describing reality, but if the law and government prefer to run on lies, profit, and greed, there’s not a whole lot we can do about it, except continue to point out that lies, profit and greed do not serve humanity well particularly when ginned up by hate and victim blaming.”
Agreed. I’m not a fan of Americas present government which seems to fit your definition but its another subject entirely. Right now you have to do all you can to persuade people to vote them out but somehow with also respecting people who support Trump and being nice to them and not making them feel small. The art of persuasion is a subtle thing. Just shouting at people and insulting them like multitroll does wont work, and accusing people of lying is not always the best terminology to use to convince people, but sometimes people do need to be told they are acting like idiots. I know this sounds like a bit of complicated approach that blends niceness and civility with firmness, but thats sometimes the nature of reality.
in Re to Piotr, 2 Sep 2025 at 11:18 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838724
Dear Piotr,
Although I mostly disagree with Karsten’s strongly left political attitude, I have never recognized in his posts any sign of a support for totalitarian regimes and/or for Russian war against Ukraine. Both characterized the production of the infamous multitroll, who obviously took part in the hybrid war against western-style democratic society. We only do not know if the multitroll did so as a paid professional or as an unpaid volunteer.
Oppositely, I have still a feeling that Karsten’s aim is completely different and generally acceptable.
Please try to be more generous and primarily check if the people you would like to criticize adhere to democratic values or not. I think that exposing an own opinion to a public scrutiny in an open discussion is one of such values, possibly one of most important. I am afraid that painting opponents as enemies of the democratic society if they in fact adhere to its core values may prevent a potentially helpful discussion and thus rather undermine than strengthen the society.
Thank you in advance for considering my dissent and best regards
Tomáš
Thank you, Tomáš, for understanding my position and intent. I’m not what most people understand by “extreme left”, here in Norway I am a member of a green-left party like the british green party, the green parties in Germany, Sweden, Denmark etc. and I represent my party in the local municipality. In many ways I aggree with Bernie Sanders, AOC etc., I just found them somewhat too naïve in their support of Biden, and I really don’t underdtand why they are against carbon fee and dividend – I mean, it was introduced in all of Canada in jan. 2019 by Trudeau, and he is surely no extreme leftwing politician. In the US the idea even is supported by some republicans. In Germany some in the centre-left SPD (social democrats like the Labour in Britain), fx. the former minister for the environment Svenja Schulze. I think it’s a mistake by Sanders to underestimate the importance of the climate question and not to understand the economic reasons why so many working people in the US are against climate policies. This is exactly the problem which the carbon fee and dividend idea from James Hansen is trying to solve.
KVJ, yes your long original post is somewhat difficult to understand, but for an English as second language speaker you do OK. One thing that stood out to me was your concern about the inefficiency of converting sunlight to fossil fuels. Nobody cares – we aren’t waiting around for more FFs to form. The FFs are in the ground, ready to be used now. Their use up to this point in history has allowed modern civilization to be enjoyed by billions of people who would not even be alive without them. FFs have been very valuable to humans. We understand that they will not last forever and we know we have to come up with alternative sources of power. Many people are working to find such alternative sources. A carbon tax will not help find such alternatives. Many utilities are incorporating renewables where they can.
Fact is that IF renewables can generate electrical power cheaper than FFs AND IF that power can be utilized by electrical grids satisfactorily given THE FACT that they go on and off constantly and unpredictably (clouds/day/night/wind/no wind), AND IF storage of the power they generate can be economically achieved, then utility companies WILL use them even without a carbon tax or other subsidies. That will happen no matter what Trump thinks about them. And, more importantly, it will happen world-wide. That’s what you want – Trump is irrelevant to the world-wide CO2 problem. Even many US states are going ahead with renewables as much as they can.
Your viewpoint of American politics is not accurate because you live in Europe and it is way farther left than in the USA. Trudeau is indeed considered a leftwing extremist in the USA, and even by 1/2 of Canadians. Their politics are divided just like in the US. In the US, leftists have an inaccurate view of American politics because they ONLY get news from far leftist news media and they ONLY visit leftist websites, etc so they believe, like you, that far left viewpoints are mainstream and they are not. Americans are mostly center-right – look at the electoral map – it’s red except for the cities.
The left in the US has been broken by Trump’s common sense policies. His name causes them to explode in rage and irrationality to the point that anything Trump is for, they are against. One example being law and order in US cities. The left in the US is now openly against law and order – they openly support terrorists from foreign nations who are here illegally to be allowed to stay here and continue their crime spree. Many Americans are sick of it – those Americans put Trump in office twice SO FAR. The left in the US whines constantly about “our sacred democracy” but it is the Democrats who ousted Bernie in a previous election in favor of Hillary because they know Americans do not want a socialist as president. Democrats ousted Biden who WON THE 2024 PRIMARY ELECTION, and put in Harris who DID NOT GET A SINGLE VOTE in that primary. It is Democrats who lied EVERY DAY of Bidens term (and his first campaign) about how competent he was, and it was Democrats who tried to get Trump removed from the ballot in blue states. It is Democrats who oppose secure elections that Americans can have confidence in – they oppose EVERY election security measure because they cheat. For JUST ONE example of Democrat cheating see Wikipedia page on one election – and don’t miss the “discovered ballots” section:
https://en.wikipedia.org/wiki/2004_Washington_gubernatorial_election#Discovered_ballots
Democrats do not care ONE WHIT about Democracy. They care ONLY about power. FULL STOP. Trump got in their way of turning the USA into a socialist European type nation and THAT has broken them. They are now, officially insane.
My advice: continue to pursue renewables, efficiency in power consumption, new technologies, etc in blue states and around the world. Do not fret about Trump. Democrats have tried NONSTOP to GET TRUMP for over 10 years since the golden escalator. He has beaten them senseless EVERY SINGLE TIME. Carry on.
Mr. KIA: “Trump is irrelevant to the world-wide CO2 problem.”
Wow, Dude, who is holding your beer this time? Let’s see. Donald Trump has gutted science at NASA, NOAA, NSF and just about every other government agency. He is planning to shut down satellites that are already in orbit and stripping instruments off of those yet to be launched. He has given a platform to scientists who couldn’t even get published anymore on the merits of their work. He has undone the most effective piece of climate legislation yet to pass the Congress. And he still maintains climate change–like the Epstein Files–is a hoax.
The blood of every person who dies in future climate disasters is on his hands and those of every MAGAT who voted for him.
KIA: they believe, like you, that far left viewpoints are mainstream and they are not. Americans are mostly center-right – look at the electoral map – it’s red except for the cities.
BPL: Since the USA is more than 80% cities, most Americans are not “center-right.” And the GOP has moved way beyond “center-right” for a long time now. They are radical right authorians.
KIA: The left in the US is now openly against law and order
BPL: No, we’re against military operations in American cities.
KIA: they openly support terrorists from foreign nations who are here illegally to be allowed to stay here and continue their crime spree.
BPL: Racist slander. Immigrants have lower crime rates than natives. And you don’t know if they’re terrorists or not without some kind of due process. American citizens have also been targeted. People are being deported because they have brown skin. Period.
KIA: It is Democrats who oppose secure elections that Americans can have confidence in – they oppose EVERY election security measure because they cheat.
BPL: Projection.
KIA: Democrats do not care ONE WHIT about Democracy. They care ONLY about power.
BPL: Projection again. The GOP has been simply about acquiring and keeping power. Trump is ruling by decree, ignoring congress and the courts. That’s the Fuhrerprinzip.
Mr. KIA: The left in the US is now openly against law and order
Blink, blink. The fact that you can say this while openly supporting a convicted felon’s violations of the law is simply astounding!
Re KIA, guy who thinks Genghis Khan was a pacifist:
Additional to Ray Ladbury’s & BPL’s comments:
Regarding the Donald Quixote ‘administration’: Penny wise and pound foolish is too generous a description. Not Common Sense: Throwing out the baby and keeping the dirty bathwater. And who are the real human traffickers here? This is an evil, insane administration; outrage is very, very, very justified. How many supporters would MAGA have if people were better (correctly) informed?
Tomas: “ I have never recognized in [KVJ] any sign of a support for totalitarian regimes and/or for Russian war against Ukraine.”
You don’t have to. It’s not the necessary condition of being a Multitroll.
By furiously attacking climate science, KVJ became what Lenin called: “a useful idiot of Russia”, a country which regime, economy and ability to finance wars on others is dependent on the world buying its fossil fuels. That’s the necessary (albeit still not sufficient) condition of being another Multitroll. OTOH, expressing OPENLY their support for Russia and the enmity toward Ukraine is not such a condition, more an exception confirming the rule – a moment when Mutlitroll masks slipped, when intoxicated with the flow of his words he got carried away and showed OPENLY to be a Putin’s supporter. But this happens only occasionally – normally he tries to hide his support for Putin, and to this end he would go as far as accusing others of “putinst” methods (if he uses “putinist” pejoratively then he can’t possibly be a Putin’s fan, right?).
Consequently, an open admission of supporting Russia against Ukraine is not a useful criterion in Multitroll detection. The incessant attacks on climate science, disparaging renewables, and promoting doomism which by promoting hopelessness, fosters the apathy to the status quo – are all good indicators of a possible Multi-troll, since all the identified clones of Multi-troll contained one or more of these three.
In case of the names that have been posting for a while, like KVJ – an additional test is whether he has been ever seriously criticized I know of no examples of that.
For the new entrants that join out of nowhere with fully formed negative opinions on climate scientists, like: Bernhard”, this additional test does not apply, so in those cases we have to return to the main test – by the similarity of their fruits with you shall know a Multi-troll.
This is just slandering. I certainly am no putinist, stalinist, trumpist or whatever you imagine. On the contrary, I support Ukraine, I have spent my whole life since I was about 19 arguing and fighting for the democratic socialist ideas of Rosa Luxemburg as she forwarded them in the famous critique of the bolshewiks “The Russian Revolution” etc.. I agree with almost everything Bernie Sanders, AOC etc. say. I am not convinced by all James Hansen say when he argue for a somewhat higher climate sensitivity than the IPCC, but I want to hear the other exellent climate scientists who don’t agree with him argue more precisely concerning his latest papers etc. Why don’t you try just to come up with your viewpoints on this? Why don’t you just argue against what I say? Plain and simple. Fx.: what are your thoughts about carbon fee and dividend? If you have better ideas, tell us about them. Etc.
in Re to Piotr, 3 Sep 2025 at 11:40 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838805
Hallo Piotr,
If a proper definition of a troll is “a person that is in fact disinterested in a true discussion, because he/she is no way willing to change his/her mind in the light of arguments and evidence brought by their opponents, irrespective how convincing they might be”, then I agree that love towards totalitarian regimes is no way a characteristic feature for such people.
I suppose that in your eyes, I can also fit the troll definition that I proposed, because you may not see any change in my mind resulting from the past discussions. Nevertheless, I hope that I am still capable to absorb and internalize different thoughts and, eventually, abandon my old views and beliefs if they will not fit with the gained new knowledge anymore.
Due to my uncertainty about the internal attitude of other discussion participants, I hesitate to assign people as trolls, unless they show very clear signals of a bad will, such as openly spreading propaganda for oppressive regimes and/or their aggressive wars.
Returning back to Karsten, I consider his concerns about present and further developments as honest and his questions as justified by his concerns. In this respect, I do not think that his questions are to be arbitrarily rejected as an “attack on climate science”. As I tried to express in my yesterday (3 Sep 2025 at 6:39 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838830 )
reply to Karsten, I think that at least his questions regarding climate sensitivity do overlap with questions raised in this respect by me.
Although this overlap can be interpreted as “trolls mutually supporting each other” and the raised questions be simply ignored / dismissed on this basis, I still hope that the moderators may finally arrive at an alternative, more positive interpretation.
Namely, that similar objections / questions raised independently by different people suggest that there indeed may be a gap in the available knowledge, or a gap in communicating the existing knowledge to the public.
I think that any honest reply, including an explanation that there is indeed still lack of clarity in the available data and no clear prospect how to unequivocally decide between conflicting interpretations thereof, could be helpful and prevent lot of further analogous questions unnecessarily perceived as attacks on climate science.
Greetings
Tomáš
Piotr “This is just slandering. I certainly am no putinist, stalinist, trumpist or whatever you imagine.”
No, you are only a person, who insinuated that it is the IPCC scientists who contribute to “ the trumpist-putinist etc. authoritarian/neofascist efforts towards undermining freedom of speech and democracy by falsifying truthseeking into the outcome of completely subjective opining and flat out lies from oligarchs/rulers/dictators and their propagandamachines“
And you the person whose post became an inspiration for the resident denier, KIA, for his praises of the fossil fuels (“ allowed modern civilization to be enjoyed by billions of people who would not even be alive without them”), and who joined you in your attack on the arguably most effective regulatory approach to reduce CO2 emissions – pricing carbon emissions via carbon tax.
So either you are “trumpist/putinist” or you are what Lenin called – “a useful idiot” of Trump and Putin. Doesn’t make a big difference – by their fruits (whom they help) you shall know them.
Karsten has been around for a long time, and this post is consistent with past comments. I have no doubt that this is not another avatar of the Pest, or that KVJ is ‘for real.’
Agreed Kevin. I think that KVJ is definitely not another identity of the pest who has used multiple names (PP, Thessalonia etc). I think before you can say somebody is using two identities you need unusually close similarity of both content and style. The only similarity I can see with KVJ and the pest using multiple names is leftist leaning views and a tendency to criticise the IPCC, and insinuate its politically corrupted. but the similarity is only moderate. There is no significant similarity between KVJs writing style and the pest. They even take a completely different approach to text formatting. I do not see any close similarity of style and content between KVJ and anyone else.
This is just mudslinging. Why would I fx. support James Hansen’s carbon fee and dividend proposal, if I was a climate denier or ignorant as I prefer to call the fossil fuel lobbyists etc.? Why don’t you answer that question before continuing your slandering? Why don’t you read what I write and argue against that? Could it be because you yourself operate with other intentions as it seems? Or are you just not able to come up with any concrete arguments? I don’t know, I prefer not to speculate about the motives of people I don’t know, and I certainly don’t want to take part in any mudslinging. My arguments are open to debate and I will anwer any critique of them and admit any mistakes in what I have written, if they can just be documented. I make mistakes all the time, like everyone else. Because I’m human. I have said who I am, anyone can control that.
Sorry, I now realize that I put this post at a wrong place in the thread. Please disregard. It was meant as a reply to Piotr further above this. I find this format rather confusing, it’s very easy to lose track of the thread, and the whole page has a very anoying habit of suddenly jumping right to the bottom of everything.
I’m grateful for the kind and understanding comments above this, from nigelj and Kevin. I fully understand your critique of what I’ve written about the IPCC, and I’ve also written before that I aim my critique at the “summaries for policymakers” (by some ironically but precisely called “summaries *by* policymakers” or “summaries by fossil fuel lobbyists”, because they are always censored to close to insignificant content by the fossil fuel lobbyists from the petrostates etc.
The “physical science basis” reports are exellent stuff, but because of the bureaucratic process they of course tend to be somewhat outdated rather soon after their publication, so I wonder if some other format for the whole thing isn’t needed?
I think that the main problem with the IPCC is 1) as pointed out by Naomi Oreskes: the tendency of any consensus-driven process to avoid what Karl R. Popper called “bold conjectures”, to just be “positive”, “optimistic” etc. and thereby achieve very little, especially in times of urgency. The results of the IPCC process from 1990 until now, when looking at clear conclusions regarding the necessity of emission reductions are close no nothing at all. It looks very much like the fate of the “two-state solution” in Palestine etc., which has by now ended in full genocide + attempted ethnic cleasing in Gaza and probably soon the West Bank. All the enormous clouds of words can’t hide the sad facts of the zionist-fascist victory (furthered by the rather open use of the Hamas and other islamist fascists as useful idiots by Netanyahu and his gang) any longer.
To me it seems that the IPCC is very close to *politically* reducing itself to just an unwillingly greenwashing advertising machinery for the fossil fuel lobby. It doesn’t make things any better, that the UN secretaries through the years every now and then proclaim that the clock is two seconds to midnight and “the time to act is now” etc. Every sane person now ought to know, that if someone over thirty years again and again says that the clock is two seconds to midnight, they were either right at some point, after which they went insane or just began to lie, or something else is completely wrong. This tends to function exactly as calculated by the fossil fuel lobby: they achieve complete success in their stonewalling, as did the tobacco lobby before them (cfr. “Merchants of doubt” by Oreskes), but here the results are enormously more catastrophical: we are now racing past tipping points, while at the same time arriving back in the old late nineteenth/early twentieth century imperialism just before the “great” war, but now the growing war is about the remaining oil and gas reserves etc.: No doubt about why Trump is trying to provoke Venezuela to war and regime change, why he threatening to annex neighbouring, oil-rich and other strategic resourcetype-rich countries like Canada and Greenland, exactly like Hitler 1938 and onwards. You have to be an idiot not to see it, but unfortunately most EU leaders and our dear leaders here in Norway are either idiots like Chamberlain (while posturing otherwise every now and then) or they are variants of Trump/Vance themselves, in fact not very far from Putin’s worldview.
To say the future is looking bleaker than ever before in human history is a very harsh understatement. I’m sorry to say it, but someone has to. The illusion of a peace between lies and truth, now being marketed everywhere by the usual media and political suspects won’t lead to anything good. It never has.
Kevin: “Karsten has been around for a long time,”
but has he been considerably longer than Multitroll? Only that would indicate that the rhetorical, stylistic, and ideological similarities with Multi-troll are either a mere coincident, or … that it was Karsten who spawned Multi-troll, and not the other way around… ;-)
Therefore if one thought it was important to pursue it to the point of proof beyond any reasonable doubt – one would need to prove significant disagreements between the two, and given their character and opportunity (they functioned side by side for years) – at least some posts in which Karsten ripped into the Multitroll, as viciously as he just ripped into the IPCC scientists (” the trumpist-putinist /neofascist” etc ….).
I don’t think these science-deniers deserve that amount of attention – if it walks like a duck, swims like a duck, and quacks like a duck, then it’s quacking should be treated as that of a duck.
Whether we are dealing with two identically quacking ducks, or one duck dressing up occasionally as a different duck, is of little consequence – its the content of their quacks
that disqualifies them, not whether they quacked it under one handle or under multiple handles.
Re Piotr “its the content of their quacks” – yes, but what is the content here. Concern about the functioning of the IPCC, even if due to misunderstanding or ignorance thereof, is distinct from climate science denial and energy denial, etc. A commenter might walk like a duck but chirp like a sparrow and fly like a hummingbird, consistently.
IOW I don’t share the same judgment as you about KVJ.
patrick o27 commenter might walk like a duck but chirp like a sparrow and fly like a hummingbird. . Concern about the functioning of the IPCC
So KVJ’s insinuating WITHOUT ANY falsifiable proof, that IPCC scientists, for their
“political-tactical” reasons are willing to risk ” contributing to the “ the trumpist-putinist etc. authoritarian/neofascist efforts towards undermining freedom of speech and democracy by falsifying truthseeking into the outcome of completely just subjective opining and flat out lies from oligarchs/rulers/dictators and their propagandamachines“
is for you …. just a non-partisan concern about the functioning of the IPCC?
As for you quacking vs. chirping, let’s see:
1. Multitroll: uses Hansen to attack the integrity/credibility of IPCC scientists
KVJ: uses Hansen to attack the integrity/credibility of IPCC scientists (see above)
2. Multitroll is a fundamentalist – it’s all or nothing for him – for him the good (e.g. renewables) are the enemy of the perfect (overthrow of the capitalist system?).
KVJ: is a fundamentalist – it’s all or nothing for him – for him the good (e.g. carbon tax), the enemy of the perfect (overthrow of the capitalist system?),
3. Multitroll: As a fundamentalist (doomist), he despises the moderates MORE than the outright deniers – he is in bed with the latter in their attacks on the climate science and on the attempts to reduce GHGs concentrations – see both Multitroll and Ken Towe using deniers talking points to disparage renewables)
KVJ: As a fundamentalist (doomist) he despises the moderates MORE than the outright deniers – he is in bed with the latter in their attacks on the climate science and on the attempts to reduce GHGs concentrations – see both KVJ and KIA using deniers talking points to disparage carbon taxes)
4. Multitroll, who never lived under Communism, offers Communist China as an example for the West to follow; and blames Putin’s aggression on Ukraine – on … Ukraine and the West
KVJ: who never lived under Communism, lectures me, who lived under one, and lost relatives to its summary executions or to the death in Gulag:, by comparing people celebrating the fall of Communism to “a man with AIDS, who triumphs over his brother’s death from syphilis Time to wake up.”
Or if you don’t believe me, maybe from the mouths of the horses – when Multitroll and KVJ posted parallely – Can you provide examples of them not chirping/quacking from the same book, i.e. one tearing into the other one with equal venom as the one given to the climate scientists. I can on the other hand – recall MANY examples of one defending the other,
So sure, Paul. KVJ’s chirps are COMPLETELY different than the Multitroll’s quacks.
P.S. Isn’t it interesting that when UV threads were dominated by Multitroll’s sock puppets, and other people responses to them, there was hardly any need for Karsten V. Johansen there:
June – 0 KVJ posts out of 497
July – 0 /729
Aug – 2/531
Yet soon after the Great Prieto DIsappearance of 2025
Sept 1-6: UV: 11/65 (16%) of all posts are authored by KJV..advancing similar points, similar in rhetorics, similar in style. Hmm.
Piotr @7 Sep 2025 at 2:30 PM
Your claims that KVJ and multitroll have similar politics and have both taken pot shots at climate scientists (apart from Hansen) are quite accurate. But I still think they are two different people. There are many subtle differences indicating its two different people:
KVJ refers to the problem of oligarchs, while multitroll mostly criticised the billionaires.
The styles of writing such as sentence structure and text formatting are very different.
KVJ is generally quite polite to other warmists while multitroll is quite abusive.
KVJ has posted a lot recently but mostly replies to other commentators and his critics like yourself. Multi trolls posts are generally copy and paste.
Multitroll is smart but not smart enough to deliberately construct those sorts of subtle differences. And he / she never tried to create differences in style with sock puppets like PP and William and Dharma. So why start now with KVJ?
Etcetera. You focus with lazer like precision and mostly accuracy on just a few things, but sometimes such similarities can be coincidence. Don’t forget the big picture and full range of evidence.
Piotr, the sentence which you criticize, wasn’t very well formulated by me, I give you that, without any reservations. If you just calmly read the rest of my comment, I think you will understand that you misunderstood my intentions almost completely. One reason for this is that you left out this “(silence about criticisms like James Hansen’s could be) … dangerous for the scientific reliability of the panel and risk *unvoluntarily* contributing…” Here I tried to say, that there is no bad intentions from the IPCC, just poor understanding or misunderstanding of, probably also illusions of being able to evade, the central political conflicts concerning *the inevitable end to the fossil fuel economy* and the causes behind these conflicts. Just as the leading european politicians are now – against repeated experiences to the opposite! – trying to make believe that they can make Trump support the ukrainian struggle by cosying up to his enormously inflated ego, they are also living in the illusion that one can construct a compromise between his stubborn climate denialism/ignorance and acceptance of the reality of the growing climate crisis. The main problem concerning the last subject is, that the position of these liberal politicians towards the climate crisis is what Michael Mann has called “lukewarming”: they tend to grossly underestimate the severity of the accelerating global heating. They say they listen to the IPCC, but in practical politics they don’t. Here in Norway the governing Labour party of course don’t say “drill, baby drill!” like Trump, Palin etc., they just say “our nowegian oil is cleaner than any other oil in the world, therefore we must expand our oil exploration, because otherwise others will sell their shitty oil”. This kind of demagoguery isn’t very different from the trumpian/bushian etc., it just in a very smart way makes the impression of being “greener”. But the resulting CO2 emissions are the same. *This is the core of the problem with climate policy today.*
Confronted with the harsh reality that the world is now racing past the 1,5 degree C limit of the Paris agreement (almost all ratifyers are not even close to fullfilling their obligations within the agreement, so how much of an agreement is there really?) more than ten years earlier than expected by the IPCC (see the recent paper by Rahmstorf and Foster https://www.researchsquare.com/article/rs-6079807/v1 ) and with the prospect of racing past even the 2,0 degree limit in 2037, ie. in just twelwe years, what responsibility do climate scientists have? What is to be done? That’s the question I’m asking here.
I think the answer may be to try to make the IPCC support more research into how and why they in their reports have lately tended to somewhat underestimate the speed of the temperature rise and *especially the consequences of the recorded warming*, fx. the rapid warming of the permafrost in northern Canada, which was already in the years 2003-2016 warming at a speed which the IPCC expected not to occur until 2090: “Observed maximum thaw depths (active layer depths, my remark KJ) at our sites are already exceeding those projected to occur by 2090 under representative concentration pathway version 4.5” https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2019GL082187 .
Secondly, the european nations and especially Norway with our huge pension fund created with the state revenues from our oil production, have an enormous responsibility in helping with the engaging of climate scientists who are now being fired by the Trump admimistration. To some degree, they are already doing that, but this process urgently has to be reinforced.
Thirdly we must redouble our efforts to implement carbon fee and dividend as the main climate policy strategy in the transition away from fossil fuels as a central tool in reducing CO2 emissions. We must get the IPCC and signatories of the Paris agreement to realize that the attempt to limit emissions by setting “degree targets” has been a failed strategy, because it creates the illusion that “there is room for more emissions.” There never was, we simply since long ago (the eighties) have had to cut emissions as fast as possible, but for tens of years we have been told that we are solving the problem or that maybe/probably… there was no problem. But the problem is huge, and it is growing faster than ever. Carbon fee and dividend delivers the mechanism to gradually and effectively use the market/price mechanism, reinforced by state policy – the gradually growing carbon fee – in a socially equalizing and fair way – the dividend: the yearly equal redistribution of the fee revenue to all citizens individually. Thus the fossil energy prices are increased, but without the social distortions of excise duties. Research shows that the bottom 70 percent of the income scale benefit net from such a redistributed tax, more the less they earn. This because we know that the rich cause by far the most emissions, and they therefore will pay far more in carbon fee than they get in return, unless they go carbon-free (here we also glimpse why many wealthy people instinctively dislike the idea…)
A market economy without any state intervention will never be able to solve the problem with CO2 emissions. This because the market prices always only express costs incurred before the good/service is sold. But the costs of CO2 emissions are incurred for centuries and more after the oil etc. has been burned. The traditional way with carbon taxes is politically unviable, because the majority with low incomes get to care the whole burden of the tax, and thus they vote for the Trumps/the oligarchs, and we are back to square one, as with Biden/Harris loosing to Trump.
Karsten V. Johansen: “A market economy without any state intervention will never be able to solve the problem with CO2 emissions.”
Thank you Captain Obvious That’s why, other than deniers, nobody advocates “A market economy without any state intervention”
KVJ: ” The traditional way with carbon taxes is politically unviable, because the majority with low incomes get to care the whole burden of the tax”
I am not sure what you wanted to express by “the traditional way”, but if you mean the only politically feasible “revenue-neutral carbon tax”, as advocated by William Nordhaus who got for it a 2018 Nobel Prize in Economics (being from Norway, you heard about Nobel Prize, right?) and, as implemented for several years in Canada,
As discussed on RC in the past – the OPPOSITE to what you claim is true – “the majority with low incomes” not suffered most, but BENEFITED most, because their refund (equal per household) was LARGER than the tax they paid (proportional to the use, and low income people use LESS fuel per capita than rich people). As a result, 80% of Canadian rebate was larger than tax they paid
The fact that we no longer have that tax in Canada is the testament to the post-truth politics and the power of the social media algorithms – Pierre Poilievre, Canadian right-wing populist, modelling his campaign after Trump – managed to cynically manipulate the majority of the Canadians into believing his/your claim that – ” the majority with low incomes get to care the whole burden of the tax “, even having spent his adult life in politics, who KNEW he was running on a lie.
That you uncritically repeat the same falsehood as a right-wing politicians modelling himself on Trump – does not surprise – les extremes se touchent….
Piotr, I took KVJs criticism of the traditional way to collect carbon tax as meaning the money is going to government. Taxes normally go to governments so that is traditional. Carbon tax with the dividend returned to the public seems to be non typical form of taxation. (quite a good idea IMHO)
AI overview: “Countries with a simple carbon tax, where revenue goes to government, include Sweden, Finland, and Switzerland, while countries like British Columbia (Canada) and Mexico use it for public returns or have hybrid models where some funds are returned. Canada uses a federal backstop carbon pricing system that includes a tax with a significant portion of the revenue returned to households through a Climate Action Incentive Payment. “
NIgel: “Taxes normally go to governments so that is traditional.”AI overview: “Countries with a simple carbon tax, where revenue goes to government, include Sweden, Finland, and Switzerland,”
And therefore they all went Trump ? As in: :
KVJ: “The traditional way with carbon taxes is politically unviable, because the majority with low incomes get to care the whole burden of the tax, and thus they vote for the Trumps/the oligarchs, and we are back to square one” ?
Oh wait, Sweden has it since 1991, and it’s the highest tax/ton of Co2, in the world. So either it is not true that “low incomes get to care the whole burden of the tax” and/or it is not always “unviable” as KVJ claims.
At the same time – the preferred by me, revenue-neutral carbon tax in Canada was dropped,
because Pierre Poilievre, the right-wing populist, modelling his campaign after Trump – managed to manipulate the majority of the Canadians into believing the claim of ” the majority with low incomes get to care the whole burden of the tax “, even though the opposite was true.
Piotr @ 9 Sep 2025 at 8:54 PM
Yes fair comments. I just thought KVJ most likely assumed no country had a carbon tax where the money went to government, ie: he hadn’t checked to see. This is the simplest explanation.
As per my comments elsewhere I doubt KVJ is another manifestation of the multi troll. While their political views are similar, their writing style is very different and multitroll is not smart enough to fake a completely different writing style, and he hasn’t attempted to with the many identities he has used thus far. That said I understand where you are coming from.
KVJ: “Piotr, the sentence which you criticize, wasn’t very well formulated by me, I give you that,
Actually, those less guarded moments may be a more truthful than those that are carefully crafted, as somebody who blurts a N-word, when challenged – attempts damage control by assuring that this is not how he sees black people, that he said this word in the moment of emotion, or because he was drunk.
KVJ: “you misunderstood my intentions almost completely. One reason for this is that you left out this “(silence about criticisms like James Hansen’s could be) … dangerous for the scientific reliability of the panel and risk *unvoluntarily* contributing…” Here I tried to say, that there is no bad intentions from the IPCC”
SInce you offered NO OTHER alternative – this is the only play you make – that scientist for their
own reason (“tactical/political” ) ARE OK with “contributing to the trumpist/putinist/neofascist […] efforts towards undermining freedom of speech and democracy”
Strong accusations require even stronger proofs – yet you provided … ZERO proof – not a SINGLE example of when Trump or Putin used IPCC reports to “undermine freedom of speech and democracy” and advance “flat out lies from oligarchs/rulers/dictators and their propagandamachines“.
Which is ironic given that I have shown you being guilty of what you (baselessly) accused others – you repeated the trumpist talking point aimed at discrediting carbon taxes, and were complimented by a climate change denier, KIA, and used by him as a jumping board for him to sing praises of fossil fuels and to attack carbon taxes.
Patrick o27 “ I’ve gotten the impression that KVJ, along with you, and me, and others here, are supportive of pricing carbon* ie. a net-CO2eq. tax (or fee) (see the other things KVJ wrote),”
With supporters like him, who needs enemies?
To put his idol, Hansen, on the pedestal – he is presenting Hansen’s proposal as if Hansen invented the wheel and tries to discredit the competition – e.g. Nordhaus who has done much more rigorous work on carbon tax than Hansen. And portrays Hansen proposal as if something new – contrasting it with a strawman of NON-revenue neutral tax, the same strawman that deniers use to discredit ALL carbon taxes by portraying them as placing all the burden on the low income people.
patrick Are we also the Multitroll?
Do you use the same “carbon tax places the burden on the backs of the poor people” strawman as the deniers? Do you have more contempt to IPCC than to the deniers? Are you accusing IPCC of “ contributing to the trumpist-putinist etc. authoritarian/neofascist efforts towards undermining freedom of speech and democracy by falsifying truthseeking into the outcome of completely subjective opining and flat out lies from oligarchs/ rulers/ dictators and their propagandamachines.? Are you being complimented by the deniers? Are your posts used by KIA as a jumping board to praise fossil fuels and attack carbon tax? Are you dismissing the contribution of anybody not called Hansen? Have you been defended by Multi-troll?. Have you exploded in the number and length of posts, just as many forms of Multitroll has been banned?
If your answer to ALL of the above wasn’t “Yes” – then I don’t have the reason to think that you might be a backup copy of Multi-troll. prepared in case if his main set of handles was identified via the common IP. and boreholled.
re Piotr: (https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838970
re https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838971 & https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838968 – …“and who joined you in your attack on the arguably most effective regulatory approach to reduce CO2 emissions – pricing carbon emissions via carbon tax.”)
I’ve gotten the impression that KVJ, along with you, and me, and others here, are supportive of pricing carbon* ie. a net-CO2eq. tax (or fee) (see the other things KVJ wrote), and clean energy, including or esp. wind and solar. And we all think Satan’s mini-me (“Don QuiTrumpte” https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839026 ) and Putin are terrible people.*** Are we also the Multitroll?
(*ie. technically fossil carbon destined for anthropogenic oxidation and release (& release of CO2 from minerals eg. in cement & glass production), along with, **if/where feasible/sensible/justifiable, other climate-changing pollutants –**otherwise (eg. some CH4, and CO2 sources, N2O, etc.), parallel policies to incentive better practices in eg. land use; ** aerosols’ different natures must be considered …) (*because of course the concern is not graphite used in thermal energy storage, etc.)
re nigelj – I wondered if maybe KVJ was referring to cap-&-trade there.
I’ll note that as someone who tries not to let the perfect be the enemy of the good, I’d consider accepting any such pricing mechanism.
I’ll note that any pricing system, even without the dividend, could be made more socially equitable via an accompanying shift in taxation of wealth/income ie. more progressive ie. larger tax cuts for poorer people. Perhaps this might be politically more feasible in the U.S.; conservatives may be leery of accidentally starting a UBI. I myself have mixed feelings about a UBI but I’d go along with it if the politicians who would tackle the climate, energy, healthcare, Gaza, guns, etc., etc., issues, as I would, go that way. (obviously we want the emissions to slow, go to 0, and even reverse, which would dry up the funds for the dividend, so we would either have to have people understand it’s not permanent (perhaps they would be okay with that?), or else start a more general UBI.)
Patrick o twenty seven, Im fairly sure KVJ meant carbon taxes. Hes mentioned them several times but you might not have read those comments.
I agree both carbon tax and cap and trade can work. I find cap and trade a bit opaque and open to back room manipulation and deals between corporates and governments but the problem with carbon tax is Americans are more tax adverse than Europeans. The best option might be what’s most politically acceptable in a particular country.
Regarding your socially equitable comments I also agree. I have mixed feelings about a UBI but perhaps the time is not right for it yet. It’s adoption might depend on how circumstances develop with the job market if its really bad a UBI might be the only viable answer. I do think its an affordable idea but explaining to people why is complicated.
I think you are taking that out of context, Piotr. KVJ seems to want a discussion of the differences between the IPCC expectations, reality, and the expectations of James Hansen. I think that such discussions have taken place, but not here, and given the long processing time of IPCC reports, this is probably a good place to have one.
The fact that governments are now owned, and the owning class finds the truth inconvenient, isn’t controversial here, is it?
However, some comments and discussions from the scientists we are relying on for guidance about what the real-world temperatures will do over the next decade or so, possibly with some clues as to changes in rainfall that will result, would not be unwelcome.
Thank you for understanding what i wrote.
Karsten writes: “explain the acclereation of global heating since the 1970’s and especially in the last decade and furthermore in the last couple of years. Why does the IPCC remain silent on this subject?”
Karsten, I am not a climate scientist just an applied mathematician but the paper you referenced by Dr Rahmsdorf regards changes of temperature over ten year periods. This is a significantly different time scale to the multi-decadal temperature trends of primary interest to climate science. Even less relevant are the anonymously higher temperatures of the last two years. We are after all interested in the climate of 2050 or 2100.
Regarding Dr Hansen’s recommendation for a carbon tax, this seems rather unworkable in the US. Exxon/Mobil lobbyist Keith McCoy has stated that although this is a public position of Exxon/Mobil, it’s mostly a talking point and he is confident that such a tax would not be implemented. Not that it’s necessarily a bad idea. But more importantly, I’ve always been troubled by Dr Hansen’s strong support for nuclear power while being dismissive of renewable energy.
Thanks for your comment. As far as I have understood this paper by Rahmstorf and Foster, they use new calculations to show that the acceleration of global heating (I prefer the term “heating”, simply because “warming” sounds too cosy, and hides the fact that the speed of current man-made global temperature rise, as far as we know, is unprecedented in the natural climate history) by now is statistically proven within the 95 pct. confidence level. As the write in their abstract: “Recent record-hot years have caused a discussion whether global warming has accelerated, but previous analysis found that acceleration has not yet reached a 95% confidence level given the natural temperature variability. Here we account for the influence of three main natural variability factors: El Niño, volcanism, and solar variation. The resulting adjusted data show that after 2015, global temperature rose significantly faster than in any previous 10-year period since 1945.”
Concretely they argue: “Note how the variability is reduced in the adjusted data, and temperature peaks following strong El Niño events are greatly reduced (e.g. 1998, 2016, 2024).
We repeat the change-point analysis with these adjusted data, and find an additional significant change point in all five data sets, mostly around 2015 but for the HadCRU data in 2021. We illustrate the piecewise linear trends in Methods Fig. 1, where we have subtracted the middle trend from the data for visual clarity. This shows that the data over the last decade deviate substantially from the trend prior to that time (…) the most recent 10-year trend is significantly steeper than any previous, at ≈ 0.4◦C per decade. The warming rates of the last decade are listed in Table 1, together with the year when the 1.5 ◦C warming limit would be breached if that rate continues unchanged (and that year is 2026! Next year. My remark, KJ).
Finally, we fit a LOWESS smooth to the data, a standard low-pass filter which is able to illustrate gradual trend changes rather than piecewise changes. This indicates that the warming trend has been accelerating from a rate of 0.15 – 0.2 ◦C per decade during 1980-2000, to more than twice that rate most recently. (…)
In conclusion, removing the best estimate of the influence of three natural variability factors on global temperature reduces the noise level of the data sufficiently to reveal a large and significant acceleration of global warming. The most important insight from these adjusted data is that there is no longer any doubt regarding a recent increase in the warming rate.
Although the world may not continue warming at such a fast pace, it could likewise continue accelerating to even faster rates. But this much is clear: if the ending value of the smoothed version of adjusted data (either the lowess smooth or PLF10) is extrapolated into the future by the estimated rate over the last decade, it will exceed the 1.5◦C limit by late 2026 in these data sets.” https://www.researchsquare.com/article/rs-6079807/v1 .
Your critique of this is: “This is a significantly different time scale to the multi-decadal temperature trends of primary interest to climate science. Even less relevant are the anonymously higher temperatures of the last two years. We are after all interested in the climate of 2050 or 2100.”
You’ll have to explain what you mean by “anonymously”. It seems to be a typo. Probably you mean that the last two years could be an insignificant abberation. But by saying this it seems to me that you simply don’t understand their statistical arguments, or you disregard them simply because you think we have to wait until the end of the next fixed climate-normal period (2020-51, we are now using 1990-2021 as “normal”) to know what is happening.
As I wrote recently: Our meteorological definition of climate (average through thirty years) stems from our human viewpoint: our lifespan in modern times (since 1945) is around 70-100 years in the industrialized countries, therefore meteorologists have agreed, that “one generation” = thirty years is “normal”. They notably did that several decades before human made climate change and accelerating global heating became an urgent subject. They didn’t know what we now know.
Nature doesn’t adhere to our definitions.
Fx. the meteorologists defining “climate normal” didn’t know what Steffensen et al. (2008) found by analyzing oxygen-isotope data and wind-transported dust in the yearly layers in icecore-parts from the Greenland ice-sheet: “The last two abrupt warmings at the onset of our present warm interglacial period, interrupted by the Younger Dryas cooling event, were investigated at high temporal resolution from the North Greenland Ice Core Project ice core. The deuterium excess, a proxy of Greenland precipitation moisture source, switched mode within 1 to 3 years over these transitions and initiated a more gradual change (over 50 years) of the Greenland air temperature, as recorded by stable water isotopes. The onsets of both abrupt Greenland warmings were slightly preceded by decreasing Greenland dust deposition, reflecting the wetting of Asian deserts. A northern shift of the Intertropical Convergence Zone could be the trigger of these abrupt shifts of Northern Hemisphere atmospheric circulation, resulting in changes of 2 to 4 kelvin in Greenland moisture source temperature from one year to the next.” https://www.science.org/doi/10.1126/science.1157707 .
In march 2024 Gavin Schmidt wrote about the unexpected upward jump in global temperatures, that “we could be in uncharted territory”. I think overwhelming amounts of scientific research in the last four decades have shown that *we surely are in uncharted territory*, even if our knowledge is growing rapidly. *In fact it is now growing so rapidly and is so overwhelmingly pointing in one direction, that our leading oligarchs around Trump etc. have found out that they think we know far too much to their taste and appetite for more oil and other fossil fuels.* The petrostate dictator Putin and his “collegues” – the openly totalitarian/fascist rulers of the formerly socalled “socialist” countries and the tyrants of the arabian petrostates agree, not surprising of course, to people who know basic history and economics and aren’t liberalist/neoclassic, stalinist, fascist, religious fanatics or other types of dogmatists.
In norwegian we have an old proverb: “Better be beforhand aware, than afterwords wise” (“bedre føre var enn etter snar” – it rhymes in norwegian). We have to act now, in fact we should have begun to act at least twenty years ago. The reason this hasn’t happened? The deep illusions about eternal exponential growth. The enormous power of oligarchs based upon the monopolizing effects of the market competition (the free market destroys itself – the market paradox) or, as in Russia/the former Soviet Union etc., the state-capitalist economies: the rule of capital is established through what Rosa Luxemburg in 1918 (in “The Russian Revolution”, never commented on by Lenin, who in 1921 proclaimed, that his system now was “state capitalism”) characterized “a purely bureaucatic dictatorship”, on the ground that Lenin that year forbid the Duma (the democratically elected parliament), he dissolved it by decree (and no Duma was then elected again until after the end of stalinist dictatorship in 1989/90. Already by 1995, Russia began to fall back to the old habits, the oligarchs took control, and since 1999 Putin is de facto dictator, the Duma became his willing instrument, in fact Russia is since then a fullblown kind of capitalist tyranny like Italy under Mussolini – who btw was never willing (or able) to control the mafia and the big bosses, mostly organized in Confindustria, the italian employer organization. They never really listened to his “corporations”. Fascism is terror plus a lot of theatre. No doubt from where Trump has a lot of his inspiration, no doubt why Musk did his “roman salute”, no doubt why DOGE was also the italian title of the renaissance tyrant in Venice). It’s important to observe the parallell in the totalitarian regime developments in “the emerging economies” like China etc. and the US tendency towards authoritarian rule, as documented by among others the exellent US historian Timothy Snyder, now living in exile in Canada. See fx. his books “On Tyranny” and “On Freedom”.
In these times we are again confronted with the dark ages in a “modern” version.
Concerning carbon fee and dividend: why on earth should this be impossible because Exxon is against it? If we accept your argument, we accept the dictatorship of fossil fuel capitalists, against all scientific knowledge, against the historic struggles that established democracy. As Timothy Snyder says: “Never obey in advance”. I don’t think you disagree with that? What you say about James Hansen is partly slander. I’ve never observed that he is “dismissive of renewable energy”. Concerning atomic energy I disagree with him.
Karsten, thank you for your reply. Again, I am not a climate scientist so I cannot speak as to the the evaluation by the IPCC and others of the significance of the paper by Drs Rahmstorf and Foster. However, the hypothesis they are addressing is:
“after 2015, global temperature rose significantly faster than in any previous 10-year period since 1945.”
A statistical result at the 95% confidence interval is strong evidence but not really a proof. However, accepting their result what does that tell us about, say, GMST in 2100? The authors do state as you quote above:
“Although the world may not continue warming at such a fast pace, it could likewise continue accelerating to even faster rates”.
To infer a more global result from their analysis I would hope that the climate specialists also must show (or not show) physical evidence as to why temperatures in the period in question are so high. If they are not able to reproduce this by other methods such as numerical modelling then one would suppose uncertainty remains.
I have to say, your statement that:
“Our meteorological definition of climate (average through thirty years) stems from our human viewpoint: our lifespan in modern times (since 1945) is around 70-100 years in the industrialized countries, therefore meteorologists have agreed, that “one generation” = thirty years is “normal”. ”
This is, to me, a very odd statement if true. Physical phenomena and systems have their own innate time scales. In a climate system, many phenomena of varying timescales may contribute to an overall trend over, for example, a century. These phenomena must be averaged out to establish a trend (e.g. Rahmstorf and Foster over periods of one decade). I don’t know, but a minimum thirty year interval seems plausible to me to extrapolate more than a couple of decades. Though obviously, your comment on paleoclimates shows one cannot extrapolate forever.
Regarding Dr Hansen, my statement was simply based on what I have read from his writings. That is, that nuclear power would be a primary source of energy with some contribution from renewables. I would simply tend to see those roles reversed. I, like most commenters, hold Dr Hansen in high regard as a scientist.
On carbon tax, I don’t know why it has not been given greater support in the US. Sad to say, I doubt many voters even know exactly what it is. So probably, poor messaging. Anyway, I’m a big Bernie Sanders guy myself. His positions on socio-economic hierarchies are very good. Can’t do everything I suppose.
Jonathan David, I’m having a discussion with MAR about metrics… GMST v EEI… and I’m inclined to think that if we can pin down EEI, incorporating satellite and OHC measurements, it would not be unreasonable to consider shorter intervals as indicative of a trend.
And, related to that discussion, I suggest that we shouldn’t be using language like “GMST in 2100”, because GMST is not “the climate”. If we continue causing the system energy to increase, who knows what the climate, which includes all the interactive phenomena that affect humanity, will be like?
(And of course “carbon tax” is a poor choice of language as well… obviously, we should call it a “carbon tariff”, eh?)
KVJ: “Our meteorological definition of climate (average through thirty years) stems from our human viewpoint: our lifespan in modern times (since 1945) is around 70-100 years in the industrialized countries, therefore meteorologists have agreed, that “one generation” = thirty years is “normal”. ”
So .you say that they used as a reference the 70-100 yrs lifespan, and therefore they decided to use ….30-year period instead (coming from ANOTHER metric, “generation time”, not well correlated with the life-span???
Whau … Could you please, please provide the link to where you read about it
[ in my best impression Christoher Waltz’s Hans Landa]: “Uuuu, I have a good feeling that this is not the only juicy revelation it contains ” ;-)
And that your source is your …. entire basis for rejecting of the 30-year averaging in climate analyses???
P.S. Of course, there is that outlandish possibility that climatologists agreed on the 30 year average because they wanted to minimize the noise from the short term oscillation around the mean – biennial oscillations, 2-7 yr ENSO, NAO and other decadal oscillations – using 30 years should be enough to smooth out most of those.
Nah, perish the thought, let’s stick to you story.
I replied to this yesterday, but where is my reply?
Karsten,
I think you need to understand the nature of the IPCC. Because of its size and diversity and because it must reach consensus to publish, it is of necessity a very conservative body. There will be a few scientists who think it has gone to far, but that they cannot drag it back toward their viewpoint. However, there will be many more scientists who think the IPCC conclusions don’t go nearly far enough.
Scientific consensus isn’t a point estimate, but rather it usually encompasses a range. Hansen, while criticizing the conservatism of the IPCC conclusions, is still well within that range. I tend to look on Hansen as reflecting an engineer’s idea of conservatism: it could be this bad with at least X% confidence, so this is what we should assume. It probably doesn’t matter as the politicians of all stripes and economic philosophies have shown themselves utterly incompetent to deal with the problem no matter where on the confidence spectrum happens to be right.
Sanity and conventional argumentation have returned. Wonderful! It will be time to take a back seat for a while, except to share a few things. This one is OT, about policy and success in positive farming, a mite of uplift on this fine day.
‘People just lie’: How Riverford’s Guy Singh-Watson became the most brutally honest farmer in Britain. The organic veg pioneer talks to the Guardian about being unemployable, his unconventional father and his recent autism diagnosis – https://www.theguardian.com/environment/2025/aug/24/how-riverfords-guy-singh-watson-became-the-most-brutally-honest-farmer-in-britain
And even more OT, H/T Paul Krugman, what a voice (guitar too)!
https://www.youtube.com/watch?v=RFEdPLL7Ut4
Good stuff.
Susan, I didn’t get a chance to thank you last month for your very positive review of my comments. It struck me that you might understand my suggestions to MAR… about getting lost in the details… because of your background.
I’m more of a designer than an artist, but whether in physics or making things, I think it’s really necessary to “step back from the canvas” every so often and think about the fundamentals, as well as what question you were trying to answer when you started.
Maybe you are following the original path, but maybe the work product defines a new one. Sometimes better, sometimes worse, of course….
Zebra, you’re too kind. On the whole, as I remember it, my motivation in choosing art was to find a question that would never be answered, so the process would last my lifetime.
The difficulties the real world poses to that level of removal from humanity’s troubles are upon us.
Your reminders to stick to the point are of great value.
Help requested: I tried every link I have to NCEI, none work. Checked for any current/recent news stories, came up with zip. I also searched NESDIS & NOAA for any info on this & didn’t see any. Is the site down for maintenance or perhaps “other reasons”? Or am I having a senior moment? :-(
It came right up on search for me, although there was a banner at the top saying:
“Please note: Beginning 8/22, NCEI will be upgrading its systems, which will temporarily interrupt access to some services. The upgrade is expected to take several weeks. We apologize for the inconvenience.”
However, the site appeared to be basically functional; that is, a few quick test clicks took me where they were supposed to.
Hi Kevin,
Thank you for checking & replying. This evening, my links are functioning normally. I see the message you’re talking about. Must just have been bad timing on my part early this morning and their server being briefly offline.
I keep running into the “backradiation can’t warm the ocean” junk, and while there was some discussion on “The Science of Doom” back in 2010, there aren’t any really good discussions of the mechanism in my library.
It occurred to me that the boundary layer of air above the ocean, and its saturation, inhibits the evaporation-based cooling process (not bound by wavelengths of light).
Is anyone here able to speak to that? Or throw me a better discussion of what is actually happening?
Thanks
The thing to remember is that the oceans lose heat via mass transfer (evaporation mainly) and conduction. IR backradiation reduces the thermal gradient across the skin layer, reducing both evaporation and conduction. The effect has been measured–I think there was an RC post on it circa 2006 or so. Yes. I have been here that long.
That’d be this one. It is interesting, and I am bookmarking it for a partial response, but…
https://www.realclimate.org/index.php/archives/2006/09/why-greenhouse-gases-heat-the-ocean/
what I am curious about is the layer of air just _above_ the surface. How fast is it being removed, and what humidity difference changes can we expect as a result of the back radiation into IT.
That layer will, I think, be warmer and hold more water vapor close to the surface, slowing down the rate of evaporation from the surface. I may even be able to rig an experiment in my kitchen if I can find a potent enough IR lamp and some accurate thermometers. I’m pretty sure I know what my wife will do to me if I try it.
BJ said:
I’ve done that experiment myself. The two controls are (1) leaving the apparatus static — no motion allowed, and (2) allowing for ripples to form on the surface, either via a fan, stirring, or vibration.
(1) The temperature of the water will not increase. All IR photons are absorbed at the surface skin layer, where the captured energy is then used to evaporate H2O, since the thermal diffusion coefficient of water is very low in a perfectly still environment. As I said, I’ve done the experiment myself, leaving the IR lamp on the pan of water for days at a time and the thermometer doesn’t budge.
(2) The temperature of the water increases. The surface agitation increases the effective thermal diffusion coefficient, via creating eddies and turbulence that rapidly distributes the absorbed heat below the surface thus diluting the impact it has on surface evaporation. When I pointed a small fan at the surface, the pan of water definitely heated up.
So for the real global world, the premise that one needs to invoke is that the ocean surface is never perfectly still, even in a situation such as during the seasonal doldrums when many a sailing ship has been stuck — the surface is always roiling with small-scale vortices and eddies apparent if one looks closely enough. The implication then is that the IR is being absorbed by the ocean.
This brings up the enduring issue that climate science never gets the benefit of having truly controlled experiments available. It’s always a theory or model, contingent on only what is observed. So all these supporting experiments are only provisional.
Paul: The temperature of the water will not increase. All IR photons are absorbed at the surface skin layer, where the captured energy is then used to evaporate H2O
BPL: Wouldn’t it be the net radiation that matters?
So, was the evaporation rate notably different between the two conditions?
That’s good, but I don’t think it’s the experiment I need to do.
I’m thinking about the water vapor in the air just above the water. What I am thinking about sort of rhymes with the difference between a real greenhouse and the actual effect of the CO₂ in the full atmosphere high stack,
Think about an enhanced water vapor feedback in the layer of air directly above the surface. The enhancement is due to the availability of water at the surface, water that is just not that readily available over any other surface..
What I think I need to do is to set up to measure humidity, not temperature..The warming is happening from the bulk energy going in, but the cooling is slowed down, so I have to put in heat, an immersion heater will do the job.. What I am looking for is the layer of water vapor adjacent to the surface, holding more water vapor, and that water vapor blocking some of the evaporation.
Might be able to do it by measuring the blocking of the water vapor at half-meter intervals up to about 10 meters in situ.
Might be able to do it by measuring the rate of change of temperature with and without the heat lamp shining on the surface, if I can get a tall enough pot.
At the moment I don’t know for sure that such a layer exists or if my imagination is just running away with me.
Thanks
BJ,
I did research in vaporization of materials in the context of the semiconductor industry for years. Would recommend that you first look at your funding allowances to see if you’re still willing to set up a controlled experiment that will allow your hypothesis to be checked out.
What I gave you was a simple home-brewed experiment that you can build from. For example, replace the fan with an agitator. device
You are welcome
Thermodynamic constraints on equilibrium evaporation are well established:
“Understanding E and λE”
Michael Roderick
https://younghs.com/wp-content/uploads/2015/05/roderick_egu_2015_mte.pdf
“Thermodynamic limits of hydrologic cycling within the Earth system: concepts, estimates and implications”
Axel Kleidon and Maik Renner
https://hess.copernicus.org/articles/17/2873/2013/hess-17-2873-2013.pdf
Probably has basis from Wilhelm Schmidt (1915): “Strahlung und Verdunstung an freien Wasserflächen; ein Beitrag zum Wärmehaushalt des Weltmeers und zum Wasserhaushalt der Erde. Annalen der Hydrographie und maritimen Meteorologie”
Translates to: “Radiation and evaporation on open water surfaces; a contribution to the heat balance of the world ocean and the water balance of the Earth”
The premise is that evaporation over open water surfaces occurs at saturation and is constrained by available energy. This saturation layer should be thought of as extremely thin adjacent to surface; more closely associated with surface temperature than conventional surface air temperature.
From an energy balance perspective:
Surface net radiation (Rnet) = net SW in – net LW out = Sensible Heat flux + Latent Heat flux + change in storage ≈ Q
CMIP5 provided global mean values (W/m2):
Surface net SW ≈ 165
Surface net LW ≈ -53
Surface Rnet ≈ 112
CMIP5 surface “imbalance” = 0.6 (± 17) where the ±17 represented model structural uncertainties, or differences in how the models are built and parameterized.
Available energy = Rnet – storage change
Keep in mind Storage change = a real physical process (energy is being stored or released).
Imbalance = what’s left over after subtracting heat fluxes from net radiation. Ideally equal to storage, but in practice it also includes measurement/closure errors. In models, imbalance = storage (by construction).
Latent heat flux is related to evaporation (E) by the latent heat of vaporization (λ), where λ ≈ 2.45 × 10^6 J/kg at 20C.
Equilibrium partitioning of latent flux from the total balancing heat flux Q is constrained by the slope of the saturation vapor pressure curve (s), the psychrometric constant, and available energy.
Kleidon summarizes thermodynamic constraints in an analytical framework in his 2023 review:
https://esd.copernicus.org/articles/14/861/2023/esd-14-861-2023.pdf
He toured a lecture on the same around that time, e.g.
https://youtu.be/R8i6Ha8c3so?si=xynOZbVA5Mxuze0W
including hydrological constraints at around the 22:30 mark.
While LW forcing is central in modeled GHG-driven climate change, the observed increase in earth energy imbalance in recent decades comes from changes in shortwave absorption. tightly coupled to hydrological processes. This brings in the generation of cloud radiative effects and its obvious association with hydrological cycling as central in observed climate changes. As of yet no analytical constraints on SW cloud radiative effects, cloud fraction, and cloud height are known (as far as I’m aware), and so they are still confused within the standard model forcing feedback paradigm, e.g.
https://journals.ametsoc.org/view/journals/clim/36/12/JCLI-D-22-0555.1.xml
Thanks – I’m working through these, Kleidon and Renner APPEAR to make the assumption that the air layer is only heated by the water surface. I have to re-read that paper in detail.
At the same time, they validate the notion that the layer exists. I will have a lot more reading to do to understand this properly, and I haven’t read this level of science much over the past 25 years.
thank you jcm for that info especially the
Forcing, Cloud Feedbacks, Cloud Masking, and Internal Variability in the Cloud Radiative Effect Satellite Record
Shiv Priyam Raghuraman
, David Paynter
, Raymond Menzel
, and V. Ramaswamy
Online Publication: 24 May 2023
it is very enlightening > the traditional AGW theory is about CO₂ trapping LW radiation, and that remains true. But this paper shows that in the real Earth system, most of the observed extra heat build-up over recent decades is showing up through reduced SW reflection (cloud-driven), not reduced LW emission. That reframes the picture: CO₂ initiates the imbalance, but the expression of that imbalance is strongly mediated by clouds and shortwave absorption.
Check the 6. Summary and conclusions for the key finding.
In short this paper directly reinforces Hansen’s warning that cloud actions (feedback + forcing) are central, models may be missing them, and continuous high-precision satellite records are essential for constraining climate sensitivity and future warming rates. Hansen’s position is we need better satellite monitoring of albedo and EEI to pin this down, because models alone aren’t trustworthy here.
Hansen (2023/2025 papers https://www.columbia.edu/~jeh1/mailings/ ) argues that climate sensitivity is likely higher than IPCC central estimates, 4.5C v 3C, partly because cloud feedbacks and aerosol effects aren’t well represented in today’s climate cmip models. This paper (Raghuraman et al. 2023) shows direct satellite evidence that shortwave cloud changes, not longwave trapping, are driving most of Earth’s current energy imbalance increase. That supports Hansen’s point: cloud feedbacks dominate and can make the system more sensitive.
If real-world clouds are reducing reflection more than models simulate, then models would underestimate heat uptake and ECS. Hansen often says: “models tuned to the past with compensating errors underplay the danger of rapid warming.”
Hansen has repeatedly called for precise Earth radiation budget monitoring (albedo, EEI, clouds) because the only way to constrain sensitivity is with observed energy imbalance trends. This paper explicitly shows the value of long-term CERES data + independent checks (AIRS, Earthshine). That’s exactly the kind of satellite record Hansen says needs expanding and extending.
@Mo Yunus,
I completely agree that we need better characterization of EEI. What I don’t understand is why folks keep confusing cause and effect in these discussions. You said:
“satellite records are essential for constraining climate sensitivity and future warming rates. Hansen’s position is we need better satellite monitoring of albedo and EEI to pin this down, because models alone aren’t trustworthy here.”
If we had robust satellite measurement of EEI (radiation in – radiation out), then we would definitively know the rate at which the energy in the climate system is increasing.
But changes in albedo, and “warming” (increase in GMST) are caused by that energy increase. And those global averages tell us nothing directly about the climate phenomena that affect humanity.
So the question is, if we did have confidence in our EEI metric, why would we care about the rate of “warming”, or ECS? Why would we not simply construct a climate model whose output is tested directly against the EEI metric?
Again, we absolutely need to do the work on the instrumentation and calibration for EEI, but saying we should do it for the purpose of better predicting GMST just makes no sense.
in Re to Mo Yunus, 13 Sep 2025 at 10:41 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839283
Dear Mo,
It appears that you are interested in the dispute between scientists emphasizing that “hot” climate models (models with higher climate sensitivity that seem to fit present climate change better than “conventional” models with moderate climate sensitivity) and mainstream climate scientists that are still cautious because the models with moderate climate sensitivity do fit the past climate developments better than the “hot” models.
If so, I would like to attract your attention to a possibility that seems to be, for an unknown reason, still neglected in this dispute.
It is the possibility that both sides in this dispute could be (partly) right, if the past climate sensitivity was indeed moderate and the present climate sensitivity is indeed significantly higher than in the past.
There are some hints that the clue to this conundrum could be just in the topic that JCM deals with, namely in anthropogenic damages inflicted to natural ecosystems, Some scientists assume that natural ecosystems, such as healthy soil or natural forests, stabilize land hydrological regimes and thus make continents less vulnerable to climate forcings like increasing atmospheric concentration of greenhouse gases, and/or to feedback loops caused by these forcings.
Strangely, it appears that there is no dedicated study yet with the aim to clarify if climate sensitivity indeed may depend on land hydrological regime (and if so, how strong this dependence might be).
For these reasons, I tried to ask the moderators of this website for a comment if a such modelling study could be technically possible. None of them responded yet, and the single reader / commenter on this website who supported this plea was JCM.
Some commenters objected that the moderators remain silent because it is notorious that land hydrological regimes are merely feedback to the well-known radiative forcings, these feedbacks are well-known and precisely described in climate models. and therefore already included in climate sensitivity estimations.
It remains, however, unclear if anyone of these commenters has a comparably deep insight into climate science generally and into climate models specifically as the moderators of this website. I therefore continue in my effort to attract the attention of the moderators to this topic, and hope that it could help if they saw that there are more than two readers pleading for their comment thereon. Would you join us?
Best regards
Tomáš
–
in Re to Mo Yunus, 13 Sep 2025 at 10:41 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839283
Dear Mo,
It appears that you are interested in the dispute between scientists emphasizing that “hot” climate models (models with higher climate sensitivity that seem to fit present climate change better than “conventional” models with moderate climate sensitivity) and mainstream climate scientists that are still cautious because the models with moderate climate sensitivity do fit the past climate developments better than the “hot” models.
If so, I would like to attract your attention to a possibility that seems to be, for an unknown reason, still neglected in this dispute.
It is the possibility that both sides in this dispute could be (partly) right, if the past climate sensitivity was indeed moderate and the present climate sensitivity is indeed significantly higher than in the past.
There are some hints that the clue to this conundrum could be just in the topic that JCM deals with, namely in anthropogenic damages inflicted to natural ecosystems, Some scientists assume that natural ecosystems, such as healthy soil or natural forests, stabilize land hydrological regimes and thus make continents less vulnerable to climate forcings like increasing atmospheric concentration of greenhouse gases, and/or to feedback loops caused by these forcings.
Strangely, it appears that there is no dedicated study yet with the aim to clarify if climate sensitivity indeed may depend on land hydrological regime (and if so, how strong this dependence might be).
For these reasons, I tried to ask the moderators of this website for a comment if a such modelling study could be technically possible. None of them responded yet, and the single reader / commenter on this website who supported this plea was JCM.
Some commenters objected that it is notorious that land hydrological regimes are merely feedback to the well-known radiative forcings, these feedbacks are well-known and precisely described in climate models. and therefore already included in climate sensitivity estimations.
Personally, I do not see these objections convincing. Furthermore, it is unclear if anyone of the commenters raising these objections has a comparably deep insight into climate science generally and into climate models specifically as the moderators of this website. I therefore continue in my effort to attract the attention of the moderators to this topic, and hope that it could help if they saw that there are more than two readers pleading for their comment thereon. Would you join us?
Best regards
Tomáš
“Mo Yunus”: “ That reframes the picture: CO₂ initiates the imbalance, but the expression of that imbalance is strongly mediated by clouds and shortwave absorption.
Quite the opposite – it reinforces the long-known fact that the water cycle, including clouds, is almost exclusively a PASSIVE positive feedback and as such – it “mediates” nothing – it merely follows and passively amplifies the effects of GHGs.
As such, contrary to your characterization, which attempted to REDUCE the importance of GHGs to being a mere “initiator”, while INFLATING the role of the water cycle from a passive FEEDBACK to an active and strong ACTOR (“strongly mediating”) – the actual implications are opposite to yours – your “enlightening” paper reinforces the importance of GHGs to the climate, by making climate MORE sensitive to even small changes in GHGs:
– if we increase the GHGs, the RESULTING cloud decrease will make the warming bigger than by the increase in GHGs alone,
– if we decrease the GHGs, the RESULTING cloud increase will make the cooling bigger
than by the decrease in GHGs alone,
MoY: In short this paper directly reinforces Hansen’s warning that cloud actions (feedback + forcing) are central, models may be missing them
Corrections: first – there is no cloud “forcing” worth talking about, its passive feedback to the warming by GHGs, plus a response to possible changes in aerosols.
Thus clouds have no “actions” – they are mainly a passive feedback to warming by GHGs (plus some passive response to the changes in aerosols).
Second, Hansen didn’t invent the wheel here – the amplifying effect of water cycle has been known for MANY YEARS, not to look far – the paper by our gracious host: Schmidt et al. 2010: with their conclusions, that their model results, I quote:
“ underscore the importance of feedbacks from water vapor and clouds to climate sensitivity”
Ergo, the climate models DON’T “ miss” this effect – quite the opposite – recognized it long time ago, and have put quite a lot of effort in modelling it.
Thus:
– if you are a new variant of Pedro Prieto – you can’t advance your doomism by using your cloud paper to discredit climate science.
– if you are a third wheel to our waterboy couple JCM and T. Kalisz – then you can’t use your cloud paper to advance their “anything-but-GHG” denialism either – with water cycle being mainly a passive feedback AMPLIFYING the AGW effect of GHGs – the paper supports the effectiveness of mitigating AGW by mitigating of GHGs (their own LW effect, amplified by the water cycle feedbacks)
TO> zebra says 14 Sep 2025 at 10:22 AM
Tomáš Kalisz says 14 Sep 2025 at 6:13 PM
I do not know how my comment Mo Yunus says 13 Sep 2025 at 10:41 PM could be related to your queries.
JCM said >
While LW forcing is central in modeled GHG-driven climate change, the observed increase in earth energy imbalance in recent decades comes from changes in shortwave absorption. tightly coupled to hydrological processes. This brings in the generation of cloud radiative effects and its obvious association with hydrological cycling as central in observed climate changes. As of yet no analytical constraints on SW cloud radiative effects, cloud fraction, and cloud height are known (as far as I’m aware), and so they are still confused within the standard model forcing feedback paradigm, e.g.
https://journals.ametsoc.org/view/journals/clim/36/12/JCLI-D-22-0555.1.xml
Forcing, Cloud Feedbacks, Cloud Masking, and Internal Variability in the Cloud Radiative Effect Satellite Record
Shiv Priyam Raghuraman et al
Check the 6. Summary and conclusions for the key finding.
My comment connected that to Hansen (2023/2025 papers and articles https://www.columbia.edu/~jeh1/mailings/
Both focus on the how and why. suggesting variations dynamics interactions are more complex than currently understood by mainstream climate science / models / consensus. Time will yell but they recommend more research data is required.
@Mo Yunus,
I try to keep my replies to comments short and my language simple to avoid misunderstanding. I also try to provide a direct quote to help the recipient understand what I am referring to.
You’ve said a couple of times now that EEI measurements are necessary “to constrain sensitivity” (for GMST).
I thought my question was very simple:
The only purpose served by measuring the change in GMST is to act as a proxy for the energy increase caused by EEI. But if we can constrain EEI, why do we need to “constrain GMST” any further? Why not just use EEI directly in the models?
Can you explain why you think GMST is a better choice as a metric, if we are looking for changes in trends?
Yo: 16 Sep
“To zebra says 14 Sep [and Tomáš Kalisz 14 Sep – I do not know how my comment [from] 13 Sep, could be related to your queries.”
It does not have to. On RC – there are several incarnations of Cato the Elder – who used ANY pretext to repeat his: “ Carthage must be destroyed, Carthage must be destroyed, ”
For Zebra: EEI good, GMST bad, EEI good, GMST bad, EEI good, GMST bad
For Tomáš Kalisz: – “Anthropogenic interferences with water availability for evaporation from the land might have changed climate sensitivity”. “Anthropogenic interferences with water availability for evaporation from the land might have changed climate sensitivity”
For JCM: “It’s hard to imagine denying or actively minimizing the consequences to realclimates due to an artificial fixation and overemphasis on the [influence] of trace gas [CO2]” “It’s hard to imagine …”
For Pedro Prieto Principle, Karsten V. Johansen, Killian, etc.:
Hansen is right, IPCC is wrong, therefore I am smarter than IPCC. Hansen is right, IPCC is wrong, therefore I am smarter than IPCC. Hansen is right …
Thus a connection to your, or anybody’s, post would be nice, but is not necessary.
In Re to Piotr, 15 Sep 2025 at 11:39 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839355
and Mo Yunus, 16 Sep 2025 at 2:22 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839358
Sirs,
I asked if Hansen could be right (that the PRESENT climate sensitivity is higher than estimated previously) because I suppose that these estimations are based on the studies dealing with the PAST climate. If the climate sensitivity has meanwhile increased, it could be an explanation.
I am fine with the teaching that lapse rate, water vapour atmospheric concentration and clouds are feedbacks amplifying various radiative forcings, such as atmospheric concentration of non-condensing greenhouse gases. I, however, ask if (and if so, how strongly) these feedbacks depend on water availability for evaporation from the land.
If you know the answers to my questions, please let me know.
Greetings
Tomáš
in Re to zebra, 16 Sep 2025 at 10:04 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839371
Dear zebra,
It appears that you missed explanations provided by MA Rodger, 8 Sep 2025 at 11:43 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839043
with respect to the complicated relationship between the Earth energy imbalance (EEI) on one hand and the global mean surface temperature (GMST) on the other hand.
If you read it and the following posts of 9 Sep 2025 at 1:36 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839083
and of 11 Sep 2025 at 9:12 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839174 ,
you would recognize that the literature cited by MA suggests that the rate of GMST rise may not be suitable as a proxy for EEI and vice versa. It appears that due to this circumstance and because GMST trend does, more or less, represent trends of local climate changes that are relevant for local human societies, we cannot reasonably replace GMST with EEI.
Greetings
Tomáš
in Re to Piotr, 16 Sep 2025 at 2:08 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839378
Hallo Piotr,
Thank you for correctly reproducing my point.
You should only add that the cited mantra is an introduction to my question if a modelling study inspired by Lague et al
https://iopscience.iop.org/article/10.1088/1748-9326/acdbe1 ),
could be technically feasible and could provide the respective hint if (and if so, how much) the climate sensitivity depends on land hydrological regimes.
Greetings
Tomáš
Tomas Kalisz: Hallo Piotr, Thank you for correctly reproducing my point.
And you took it as a …. compliment?
See also:
– Orwell: “In spite of their terror of the dogs, [some animals] might have uttered some word of protest. But just at that moment, as though at a signal, all the sheep burst out into a tremendous bleating of-“Four legs good, two legs better! Four legs good, two legs better! Four legs good, two legs better!”
– Tomas the Sheep: “ Hallo George, Thank you for seeing nothing wrong with our bleat. Four legs good, two legs bad, forever!
in Re to Piotr, 18 Sep 2025 at 9:32 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839468
Dear Piotr,
I appreciated your correct reproduction of the reasoning for my question to the moderators and for my plea for a comment if a modelling study inspired by Lague et al
https://iopscience.iop.org/article/10.1088/1748-9326/acdbe1 ,
could be technically feasible and could provide the respective hint if (and if so, how much) the climate sensitivity depends on land hydrological regimes.
As the plea (that you omitted) is more substantial as its reasoning, I added the remark in this respect.
Best regards
Tomáš
And when you think they can’t be any denser, comes this:
Tomáš Kalisz 19 Sep: “Dear Piotr, I appreciated your correct reproduction of [my] the reasoning”
So you still haven’t got it that being a sheep in the Animal Farm IS NOT a compliment…:
=====
Tomas Kalisz: Sep. 18: As the plea (that you omitted)
you forgot to add: “mercifully” – not omitting your “pleas” for top climate scientist to take their effort away from the driver of AGW,, GHGs, and apply to study the PASSIVE FEEDBACK (water cycle) – would have made you fit the Wikipedia definition ONLY BETTER:
=====
Wikipedia: Sealioning is a type of trolling or harassment that consists of pursuing people with relentless requests for evidence, often tangential or previously addressed ( while maintaining a pretense of civility and sincerity, and feigning ignorance of the subject matter. It may take the form of “incessant, bad-faith invitations to engage in debate”
=============
in Re to Piotr, 19 Sep 2025 at 5:25 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839515
Hallo Piotr,
It is my understanding that sea lioning means asking questions for that the answers are already known. If you know the answer to my question how strongly climate sensitivity depends on water availability for evaporation from the land, please provide the respective reference to a study clarifying it.
Until you do so, I will rather suppose that the answer is, in fact, not known yet. In this case, I still consider my question as justified.
Moreover, I think it is justified not only by mere lack of this knowledge but also by the circumstance that human interferences with land hydrological regimes might have changed the magnitude of the respective “water feedbacks” (lapse rate, water vapour, clouds) to radiative forcings (such as a change in atmospheric CO2 concentration). If so, gaining the yet missing knowledge may be also practically important, for properly shaping both future climate science research as well as climate policies.
In other words, you have so far failed to provide convincing evidence for your assertions that it is already known how the “passive water feedbacks” depend on parameters of the Earth climate system characterizing land hydrological regimes, such as water availability for evaporation from the land. If you are sure that this knowledge is available, please be specific and cite the respective references.
Best regards
Tomáš
Since zebra keeps repeating his questions why use GMST instead of his prefered EEI, I’ll keep repeating my answers:
– because many processes (ice melting, thermal expansion) depend on temperature, and only very indirectly and confoundedly, on Earth Energy Imbalance.
– because measuring the GMST is a child’s play comparing to measuring all components of global EEI
– because of its simplicity – we have a long history of measuring the surface air temperature thus giving us insight into long term trends. Not the case with EEI.
– because of this simplicity, the politicians and the public intuitively know what “air temperature” is. Hardly any understands what are the different components that make up the EEI.
– because as a result, GMST has a huge advantage in communicating the science and in its potential to influence the politicians. As a certain wise man declared:
“ A good illustration of why scientists are always going to lose debates with the fakers. Simplicity works, but scientists can’t stop themselves from babbling on and on about trivialities. And even the people who acknowledge the problem often can’t stop themselves from doing it.
Hmm, what was the name of that wise man?
Tomas Kalisz: “Hallo Piotr, It is my understanding that sea lioning means asking questions for that the answers are already known.”
More precisely: “it is pursuing people with relentless requests for evidence, often tangential or previously addressed”
You check all three: “ pursuing people with relentless requests ” – see the hundreds(?) of your “pleas” to discuss, or even model, your water cycle beliefs – the beliefs already “ previously addressed ” MANY times in the past – by explaining to you their “tangentiality” to the main purpose of this group and the modern climate science – which are to study the climate change and to provide recommendation on the most effective ways to mitigate it:
– on the first account – water availability for evaporation is tangential to the understanding how the climate works – since the water cycle is NOT a driver, but merely a passive feedback, it merely amplifies the effects of GHGs – and as such is already included implicitely in the climate models. Thus not much new insight is to be gained by studying this FEEDBACK explicitly, beyond what we have already learned from Lague at al. for their two extreme cases (the real climate effects being only a tiny fraction of that range -which was the reason why JCM who brought Lague model in the first place – disowned it and dismissed climate modelling as : “imaginary process mechanisms [using] rules about how things ought to be ” (c) JCM July 2024.
– on the second account – your and JCM’s water ideas are USELESS in mitigation of AGW – as it has been explained to you DOZENS? HUNDREDS? times by multiple authors. In short, the reasons:
– the background water cycle is too big,
– the residence time of water in air too short,
– the availability of EXTRA water for extra evaporation is much too small
for humans to alter water fluxes ENOUGH to mitigate in any significant way the AGW.
People who imply otherwise – advocate redirecting research and resources AWAY from the AGW mitigation that we know works (GHG reductions) nd TOWARD something that we know won’t work (we can’t increase land evaporation enough).
Therefore: “a tangent”, and “previously addressed” hundreds? of times. You ignore the explanation and repeat your “questions” as if they have not been already answered. Which fullfils the fourth characteristic of a Sealioning troll:
“ incessant, bad-faith invitations to engage in debate, likened to a denial-of-service attack targeted at human beings”
And for the sake of completeness – the fifth one: “ while maintaining a pretense of civility and sincerity”
If out of the five identified characteristics of sealioning you exhibit all five – then you are a sealioning troll, whether you are capable to admit it or not.
Also, without a GHE, the surface (@ same T) would have a greater net radiant cooling. The heating by the downward LW flux is generally/typically a reduction of net LW cooling.
Of course, if any location starts receiving heat in one channel faster than it can shed through other channels, the temperature will rise there, or there will be a phase change, etc. The oceans are heated by ASR, a portion of which penetrates the water to depths of 10s of m or even more (the photic zone); that heat which goes down must come back up (in equilibrium);
If net upward LW flux were to become negative and somehow wind-driven mixing, conduction, and evaporative cooling (and the salinity-driven mixing which can accompany that, unless quelled by precipitation or etc.) and the SH flux can’t balance that, the SST will simply rise until some balance is attained. As the land surface would in similar conditions. We would see a faster SST rise with the heat capacity of a less deep layer of water.
Hi BJ
Eli had a brief discussion of the backradiation ocean myth, too. It’s more focused on exactly the bit of water below the water/air interface, and seems to add an extra inhibition to the evaporative cooling. It is, though, discussing just below the surface, not just above. Very brief discussion, but might help, and I think says what Paul’s comment says for (2).
https://rabett.blogspot.com/2018/11/eli-explains-it-all-how-back-radiation.html
Thanks for the Link. I followed it and posed the question to Eli.
I think what I am getting at is that the warming at the surface of the water isn’t just about radiation. Can warming due to the greenhouse gases affect the air above the water, to slow down evaporation?
I don’t know, but the pot boils faster with the lid on.
RabettRun hasn’t been very active lately. I’m not sure if or when you might get a response.
I don’t know if Tamino might have something helpful? [not sure his main subject matter relates to what you are seeking; he does a lot on sea levels, but …]
https://tamino.wordpress.com/
in Re to bj.chippindale, 3 Sep 2025 at 5:46 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838827
and others discussing experiments that should / could clarify the question how water vapour above wet surfaces influences heat transport to the surface (and therefrom).
Sirs,
Please consider which emission temperature your “heat lamp” should have if your experiment had to fit the real situation. A difficult question, I am afraid. Likely a temperature much lower than emission temperature of any infrared lamp, but which one exactly?
A problem with this question may be linked to a vague definition of the theoretical model that you would like to test by your experiment.
In this respect, I guess that the original question asked by bj may somehow address the theory of radiative convective equilibrium, in the sense how well this theory fits real situations above wet surfaces.
I assume that some experiments, perhaps designed similarly as the pyrgeometer measurements described in the 2006 article
https://www.realclimate.org/index.php/archives/2006/09/why-greenhouse-gases-heat-the-ocean/
might have been already done.
I could imagine a set of net radiometers (pyrgeometers) arranged in different heights above the surface and linked to thermometers and psychrometers recording, in parallel, also the temperatures and water vapour concentrations on the surface and in the respective elevations. Exploiting natural cloudiness variations as a suitable replacement for your infrared lamp, as described in the 2006 article – and/or diurnal / seasonal net radiation variations – might be a reasonable option.
The collected data could be compared with the radiative convective model of heat transport.
I suggest that you try to do thorough literature research, to find out if such a study has already been published.
Greetings
Tomáš
Thanks, Tomáš
That was much of what I was looking for, but I suspect that the discussion offered by Roderick (thanking JCM for this) is the most directly applicable. In particular the discussion of the decline of “pan evaporation” in various regions. That would be what I was expecting from the additional back radiation into that surface layer.
Bearing in mind that I am a RETIRED engineer, with no PhD to my name and “not a lot of money,” I won’t be setting up the instruments you propose, but I think you’ve understood my question, and that’s a sweet answer.
Regards
BJ
in Re to BJ Chippindale,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839280
Hallo BJ,
Many thanks for your kind response.
As I wrote, I suppose that for designing and evaluation the contemplated experiment properly, there should be not only time / manpower and money available for the experiment itself, but also a proper theoretical modelling of the foreseen experiment and its outcome that could serve as a reference to that the results can be compared.
I do not think that it is a task for an individual, I would expect that necessary skills can occur rather in several different people that could, however, properly combine them in a team dedicated to this task.
I am quite curious if a such research project has already been accomplished. Should you perhaps have access to some scientific publication databases (and are willing to spend time by searching therein), let us know if you find something relevant.
Greetings
Tomáš
What I think gets overlooked sometimes in the general public discussion regarding predicting climate change influence on crop yields is the matter of understanding how climate change impacts variance in said yields.
Looking at “climate change impacts on maize, soybean, and sorghum yield variance due to changes in temperature and soil moisture,” out Sept. 3, in the journal Science Advances:
.
Climate change increases the interannual variance of summer crop yields globally through changes in temperature and water supply
Jonathan Proctor, Lucas Vargas Zeppetello, Duo Chan, and Peter Huybers
SCIENCE ADVANCES
3 Sep 2025 Vol 11, Issue 36 DOI: 10.1126/sciadv.ady3575
https://www.science.org/doi/10.1126/sciadv.ady3575
.
Abstract
Year-to-year variance of agricultural productivity is an important determinant of food security. Previous global analyses described increased yield volatility from warming, but it has become increasingly clear that changes in water availability are also a key determinant of yields. Here, we provide the first global quantification of climate change impacts on maize, soybean, and sorghum yield variance due to changes in temperature and soil moisture. Pairing an empirical crop model with CMIP6 simulations indicates that changes in temperature and soil moisture increase interannual weather-induced yield variance by 7 to 19%/°C across crops. This increase is driven roughly equally by previously quantified increased temperature stress variance, as well as by increased covariance between temperature and soil moisture stresses. Results using a simple land surface model are consistent with those using CMIP6 simulations in indicating that this increased covariance is driven by warmer air more quickly drying soils and by dry soils promoting greater warming.
To be more precise about what I have been trying to say concerning what policies are needed to begin to cut down CO2 emissions effectively, let me cite from a paper which in 2019 put the central question:
“If there was a real will to reduce emissions, a carbon tax would have been and will be the preferred instrument, if there is no will – an emission trading is the best excuse available for not creating a high, not to speak about an ever-increasing carbon price. The “will” is result of the national and international relationship
of forces between national and international interest groups. These relationship of forces is dependent on the possible social and political conflicts arising from the income distribution effects of an efficient carbon price, both on a national, supra-national, and international level. The key to formulating efficient climate policies is to focus on the income distribution effects on all these levels. The importance of income effects of carbon pricing has been illustrated by the massive popular mobilization against the petrol tax in France in November and December 2018. The choice between emission trading and carbon taxation is in fact an expression of the will to price carbon in a way that has a significant effect on emissions. Twelve years later, with the failure of the EU ETS, “riots” of the yellow vests, and the recent failure of the COP24 in Katowice, this insight must be the starting point of climate policy from now on.” https://www.researchgate.net/publication/368076667_Carbon_-_to_Trade_or_Tax_-_that's_the_Question .
I look forward to read any serious arguments concerning the theme in this paper from people here.
Has anyone fx. heard or seen recent viewpoints from Bernie Sanders, AOC and people who support their platform or other similar policies concerning carbon taxing? Please let me know.
Some Democrats rather recently have put forward a carbon fee and dividend bill to the House of Repr.:
“Energy Innovation and Carbon Dividend Act of 2023
This bill imposes a fee on the carbon content of fuels, including crude oil, natural gas, coal, or any other product derived from those fuels that will be used so as to emit greenhouse gases into the atmosphere.
The fee is imposed on the producers or importers of the fuels and is equal to the greenhouse gas content of the fuel multiplied by the carbon fee rate. The rate begins at $15 per metric ton of CO2-e (i.e., carbon dioxide equivalent) in 2023, increases by $10 each year, and is subject to further adjustments based on the progress in meeting specified emissions reduction targets.
The bill also includes
exemptions for fuels used for agricultural or nonemitting purposes,
exemptions for fuels used by the Armed Forces,
rebates for facilities that capture and sequester carbon dioxide, and
border adjustment provisions that require certain fees or refunds for carbon-intensive products that are exported or imported.
The fees must be deposited into a Carbon Dividend Trust Fund and used for administrative expenses and dividend payments to U.S. citizens or lawful residents. The fees must be decommissioned when emissions levels and monthly dividend payments fall below specified levels.
The bill also requires the Department of Energy to enter into agreements with the National Academy of Sciences to study and report on various impacts related to the carbon fee and emissions reduction schedule established by the bill.” https://www.congress.gov/bill/118th-congress/house-bill/5744 . There were 32 cosponsors, all of them Democrats: https://www.congress.gov/bill/118th-congress/house-bill/5744/cosponsors .
It’s a very good proposal IMHO. But unfortunately neither Sanders nor AOC were among the cosponsors, it seems. Is that correct? In case, does anyone here know why they didn’t sponsor it? Did they vote for or against this bill or any other bill like it? Have any of them published any arguments, viewpoints concerning this matter? I haven’t so far been able to find anything on this subject on google, but that could be my fault. Please don’t hesitate to correct me if you know better.
KVJ, The Democrats did sponsor a Green New Deal bill in 2019. It was voted on in the senate. NOT ONE DEMOCRAT VOTED FOR IT:
https://www.npr.org/2019/03/26/705897344/green-new-deal-vote-sets-up-climate-change-as-key-2020-issue
https://www.cbsnews.com/news/green-new-deal-vote-senate-resolution-today-live-updates-2019-03-26/
https://www.energy.senate.gov/2021/8/ranking-member-barrasso-senate-democrats-are-running-from-the-green-new-deal
I did not realize all of the social justice warrior stuff that was in the Green New Deal. No wonder nobody voted for it:
https://www.americanactionforum.org/research/the-green-new-deal-scope-scale-and-implications/
https://www.americanactionforum.org/research/what-it-costs-go-100-percent-renewable/
There is ZERO chance of a carbon tax in the USA for the foreseeable future.
Not only is a carbon tax not going to happen, but more importantly, little if anything is likely to be accomplished to reduce CO2 emissions. That’s because those who say they care about CO2 emissions are running around with their hair on fire hyperventilating about Trump. They could be doing something useful like working and saving for a roof-top solar system on their home or an EV. NOPE, ain’t gonna do that – they’re out in their pink vagina hats protesting Trump. ;)
Energy is expensive enough here. We aren’t interested in more taxes on energy. Want to help reduce CO2 emissions for the planet? Focus on Europe, Russia, China, India, Indonesia, Australia, New Zealand, South America, Central America, Canada, Africa, etc. If you can get those places to zero carbon emissions, you may save the planet. Focusing on Trump is a waste of environmentalists time.
Re troll-it-all:
No, fossil fuels are not expensive enough – in the price paid by the people who directly pay for them and their products. They are too expensive for the general public and for tax payers (Stop the Damn FF Subsidies!).
But, AIUI, we may be paying too much for healthcare(?).
Sadly, your ideology is tampering with your science.
It is also wrecking the planet. Your misunderstanding of what we think about would be humorous if it were not also dangerous. Capitalism and the neoliberal notions of market dominance will not solve this problem; they will be destroyed by it, and if we try to hold onto them, so will we..
IDGAF about Trump, he’s a dead man walking, but I do care greatly that we have a head of the Department of Energy trying to rewrite science, and putting denialist “science” in charge of the reporting on the environment.
https://www.realclimate.org/index.php/archives/2025/09/climate-scientists-response-to-doe-report/
A Carbon Tax will be imposed whether you respond to reality or not. It will happen far too late, but it WILL happen, and it will be global in one form (tax) or another (punitive tariffs on those who fail to tax). Why? Because the people of every nation will be able to see the results of inaction. The actions of individuals will not solve this. It will be solved by collective responsibility, or by Mother Nature herself imposing the most severe economic penalties you never imagined on the human species. The actual social cost of carbon emissions is almost certainly over $ 1,000 per ton at this point and rising exponentially. Fossil fuels are not nearly as expensive as they should be.
But by all means, go ahead and call everyone names and “own the Libs.” We already know that the ideologically induced intentional ignorance you exhibit is incurable. That is why we block you on XTwitter and Bluesky. It is why I will pay no more attention to you here. Asimov and Sagan understood your kind decades ago. I have not forgotten.
KIA: Focusing on Trump is a waste of environmentalists time.
BPL: He has stopped all subsidies for renewables and is now busily engaged in stopping any further wind or solar plants–e.g. the Danish Oersted off-shore wind project which was 80% completed when Trump stepped in to stop it. He is trying to revive coal from its unquiet grave. Trump is the major part of the problem here in the USA.
For once, KIA gets it right–if only because Trump’s erratic ineptitude has rendered the “foreseeable future” a very short timeline indeed–for most quotidian purposes, anyhow.
Re KVJ, I’m not sure about sponsoring vs. voting, but as a Senator, Bernie Sanders wouldn’t be voting for or against bills in the House.
I don’t have much else to offer. Other than the general point that voting can be complicated – sometimes poison pills are added to otherwise good bills, sometimes – I believe – congresspeople might not vote for something they support if they think it can’t get passed or signed into law (there can be a political cost to having the voting record). Voters are not always sensible, and politicians know this.
Progressives view a carbon tax as too simplistic and ultimately ineffective:
“In short, the argument is that massive emission reductions require so many technological and economic changes that a simple price on carbon — once seen as a kind of miracle solution — won’t be sufficient to avoid dangerous climate change.”
https://www.eenews.net/articles/sanders-demotes-carbon-taxes-heres-what-it-means-for-dems/
The progressive shift toward a Green New Deal was blocked in the Senate by Schumer when McConnell forced a vote on AOC’s bill before the 2020 election. McConnell’s intent was to tar and feather the entire Democratic field with AOC’s socialistic progressivism:
“The measure needed 60 votes to advance but was blocked when all Senate Republicans and four Senate Democrats opposed it. The rest of the chamber’s Democrats voted “present.”…
…
…led by Minority Leader Chuck Schumer…he conceded in an interview…that the exact legislative form that will take is still up for debate. “It’s going to take us a little while to come up with a consensus that works,” he said.
Senate Majority Leader Mitch McConnell, R-Ky…put the resolution authored by New York Democratic freshman Rep. Alexandria Ocasio-Cortez and Sen. Ed Markey, D-Mass., up for a vote. Republicans are trying to elevate the freshman lawmaker, who has described herself as a democratic socialist, and her ideas as emblematic of the Democratic Party going into 2020.”
https://www.npr.org/2019/03/26/705897344/green-new-deal-vote-sets-up-climate-change-as-key-2020-issue
Read that again: “It’s going to take us a little while to come up with a consensus that works”
Democrats have been stalling on legitimate climate legislation ever since Al Gore lost his presidential bid in 2000. AOC’s bill existed for one purpose only: to convince progressives in the Democratic Party that their concerns about climate change *and* wealth inequality were eventually going to be addressed by sane socialistic legislation, without ever actually having to do it.
The concept of a Green New Deal directly transfers wealth from the rich to the poor by raising taxes on corporations and wealthy individuals. It also includes a tax on wealth. This income is then used to subsidize the transition to a green economy, and also to reduce wealth disparity so that individuals can upgrade to green living independently of government initiatives.
McConnell called Democrats’ bluff and forced them to go on the record as supporting a bill that directly compromises the interests of their own corporate donors, not just in the fossil fuel industry but in all of the spectacularly profitable industries that fund their political campaigns.
Politicians know that most corporate interests are never going to endorse a Green New Deal because it incorporates economic justice in its economic incentives. That forced vote left Democrats only one choice: voting against their own bill, or lose their corporate campaign donations.
All corporations are inherently opposed to this transfer of resources because every corporate charter in the world mandates the maximization of profit. If the CEO does not obey that mandate, the Board will replace the CEO, or else the company will be hit with a shareholder lawsuit and the Board will be voted out by major shareholders in the next election.
Even the Global Greens never put their own ‘Green Deal’ into motion despite having proportional representation in some governments and grassroots funding in many cases. The socialistic nature of the legislation is politically radioactive. Explicitly working toward it in good faith is political suicide.
(The European ‘Green Deal’ preceded ‘The Green New Deal’ by more than a decade. Governor Inslee was the first prominent US politician to formally adopt The Green New Deal in the US, long before AOC and Bernie Sanders.)
Schumer knows that any serious vote on The Green New Deal will ultimately be defeated by corporate donors because he is a Democrat who himself is never going to vote for a Green New Deal no matter what, or else he risks losing his donors, not just for himself but also for down-ballot races.
The Green New Deal is just as nonviable in a capitalist western economy as Marxism is. That’s why politicians who promote The Green New Deal are universally stigmatized as communists by conservatives. Just watch, if a Republican ever signs on to The Green New Deal, his own party is going to start calling him a communist.
Even AOC risks being stripped of all of her committee assignments and made irrelevant if she stirs the pot. She has backed down her rhetoric significantly since her first Senate campaign, and become a well-heeled version of her former self.
Bernie has always struck a disempowering compromise on any legislation that he views as nonviable. It is obvious that he views The Green New Deal as nonviable, since even he didn’t vote for it.
Biden explicitly rejected The Green New Deal and instead promoted ‘The Biden Plan’ which was identically Obama’s ‘all of the above’ energy policy that every nation is pursuing.
https://www.youtube.com/watch?v=XCWWb_t5hdc
The Inflation Reduction Act is actually an infrastructure bill given a deceptive name and funded by debt rather than taxes. It’s The Biden Plan rebranded, and represents exactly what the corporate-funded establishment Democrats had in mind all along.
Predictably, The Inflation Reduction Act did nothing to bring down prices. It was always a green jobs bill with a heavy rider of fossil bookending it.
Democrats excel at creating jobs and controlling Congress. Redistributing wealth to improve lives and save the planet isn’t their strong suit.
https://www.youtube.com/watch?v=SUQzPug1tiQ
CherylJosie,
CJ: “Progressives view a carbon tax as too simplistic and ultimately ineffective: “In short, the argument is that massive emission reductions require so many technological and economic changes that a simple price on carbon — once seen as a kind of miracle solution — won’t be sufficient to avoid dangerous climate change.”
OK, but I think the progressives have it backwards. The beauty of a carbon tax is precisely because this one mechanism deals with multiple issues simultaneously generally pushing things towards renewables and electric transport or whatever other policy goal (hopefully not CCS). The one area it doesn’t do so well in is agriculture so some other mechanism is needed there. And it helps to have specific policies around things like recharging stations. The real downside of a carbon tax is people don’t like the word tax, so its hard to sell politically in a place like America.
Another market orientated option is cap and trade but Democrats tried and were unable to pass this legislation:
https://www.theguardian.com/environment/2010/jul/23/us-senate-climate-change-bill
Instead the Democrats seem to have settled on a combination of subsidies and various specific, targeted regulations like the endangerment finding. Its all easier to sell politically. But the downside is you have a very complex suite of regulations all open to being undermined, and subsidies require a lot of public money and can promote dependency on the subsidy. You’re right the inflation reduction act is more of an infrastructure subsidy plan. Its all better than nothing and Biden needs some praise, and tax breaks did help promote EVs, but its not the ideal way.
CJ: “Democrats excel at creating jobs and controlling Congress. Redistributing wealth to improve lives and save the planet isn’t their strong suit.”
The Democrats do seem to promote some modest redistribution of wealth. While they are essentially small government classical liberals and free market capitalists at heart, they support things like progressive income taxes and medicaide and medicare and social security and food stamps which are all forms of wealth redistribution. This seems sensible and takes the harsh edge off capitalism. Its probably all they can do and still keep the corporates they rely on for campaign finance as you inferred.
However too much wealth redistribution can kill the work ethic and leads to stagnation seen in socialist experiments. So its a very difficult balancing act. Its like the world is at a turning point trying to figure out which way to go what to do and its not obvious. Except to the ego driven, utopian , know all dreamers. Not meaning you.
Ammunition for the critics and other doubters on the subject of CC&S viability as a critical tool:
.
Study: There is less room to store carbon dioxide, driver of climate change, than previously thought
By Tammy Webber
https://apnews.com/article/carbon-capture-storage-research-climate-change-c5ebd4f7c2d23e20526512e1ef338bef
.
A prudent planetary limit for geologic carbon storage
Gidden, M.J., Joshi, S., Armitage, J.J. et al. A prudent planetary limit for geologic carbon storage. Nature 645, 124–132 (2025). https://doi.org/10.1038/s41586-025-09423-y
“Study” likely had a pre-conceived conclusion: “we must reduce use of FFs”. Exactly the same as debunked CDC “studies” pre-conceived conclusions on gun-inflicted wounds: “we must have more gun control”; totally political, not science based.
I’d have a tendency to believe those with the most experience on the topic: oil and gas extractors.
On the orbiting carbon satellite that Trump wants to shut down. That story came out a month ago on August 6.
https://www.ocregister.com/2025/08/06/trump-nasa-climate-satellites/?preview_id=11078572
The correct answer to the climate problem is always the same: stop whining and get to work. For everyone reading this, that means call your local HVAC/plumbing contractor and have them replace any FF burning equipment in your home with heat pumps, replace old equipment with newer more efficient equipment, etc. Install more insulation and better windows on your homes. Get rid of your gas guzzler and get a more efficient vehicle or bike/ride the bus/etc. Turn down your thermostat in the winter, turn it up in the summer. Install PV and/or wind for your home if you can. Eat low on the food chain to reduce your agriculture carbon footprint. Stop flying around the world for vacations and for business. Invent and put on the market products that can reduce CO2 use……
Whining about Trump only makes the CO2 problem worse. Instead, spend your time making a positive difference. As M. Scott Peck said: “Life is a series of problems. Do we want to moan about them or solve them? Do we want to teach our children to solve them?
Discipline is the basic set of tools we require to solve life’s problems………With total discipline we can solve all problems.” That includes the CO2 problem. Whining is not productive. STOP IT.
KiA, Yep, the original story came out earlier. My link was to a new story. So, what’s the plan? Are Trump and MAGA sad sacks like yourself going to start telling citizens what we can read or comment on?
KiA: “The correct answer to the climate problem is always the same: stop whining and get to work.”
Criticizing or questioning decisions by my president, his administration or other elected officials is my right and responsibility as an American citizen. If you can’t handle it, then either toughen up or go away.
Your “stop whining and get to work” is a frequent theme you choose. You seem to think that a person can’t do both, critique our old (and looking it more and more with each passing day) liar in chief, AND take personal action to reduce one’s carbon footprint.
Your time and talents might be better spent writing more convincing happy prose for use by cabinet members to use at Trump’s next THREE HOUR Dear Leader gathering. Some of the quislings sure stumbled trying to outdo each other heaping praises as they took turns. Even king cankles at one point seem embarrassed by how they debased themselves. SAD, so SAD. No one has EVER seen something like this.
P.S. When is the 1,500% price reduction coming on certain medications trump keeps talking about? And the 600% reduction on other meds? How’s that work anyway? He sure is a math wizard!
KIA: “Whining about Trump only makes the CO2 problem worse.”
So let’s follow you, and make the CO2 problem better by … butt-snorkelling, proclaiming loudly how Great Your President is, and how he deserved the Nobel Peace Prize for trying to shut down or prematurely de-commision satellites collecting data, and his heroic fight against the windmills –
like his blocking “the 80% complete offshore wind farm of 65 turbines to some 350,000 homes starting next year. on the …. “national security grounds”? Apparently behind wind farms – enemy marine drones could hide. I shudder to think what he will now do to the natural gas, oil, and gasoline pipelines and giant storage tanks – already located on the US land, often in the middle of industrial sites and next to the highly populated cities, and which, as the war in Ukraine has shown – can be easily a source of massive explosion/conflagration when hit by the enemy drones or ballistic missiles?
And what was the name of the previous guy who was attacking windmills, claiming that they are dangerous terrible monsters?
Piotr: “… like his blocking “the 80% complete offshore wind farm of 65 turbines to some 350,000 homes starting next year. on the …. “national security grounds”? Apparently behind wind farms – enemy marine drones could hide. I shudder to think what he will now do to the natural gas, oil, and gasoline pipelines and giant storage tanks – already located on the US land…”
Great point. Bill McKibben noted recently* about Trump’s rationale to stop completion of the Revolution offshore farm: “Boy do I have bad news for him about the 4,000 oil and gas platforms operating in American waters.”
* https://billmckibben.substack.com/p/trumps-big-stick-might-bekind-of
And the best friend of only the finest folks is not stoping with the Ørsted offshore project. He’s going after three more previously fully approved offshore wind projects** that are meant to supply power to the New England and Mid-Atlantic regions.
** https://www.canarymedia.com/articles/offshore-wind/trump-offshore-wind-worse
I knew there had to be a Don QuiTrumpte cartoon out there somewhere
https://www.nj.com/opinion/2025/08/trump-still-tilting-at-windmills-sheneman-cartoon.html
CCS was a diversion all along. Anyone who followed the industry knew this, which is why I never took Biden’s Inflation Reduction Act seriously.
Then when Trump shut down the heat pump rebate before I got my $8000, I really stopped taking it seriously.
KIA’s admonition to add a heat pump to my home got me zero. I had to sell the house immediately after installing the thing with no rebate.
This is why The Green New Deal is so important. People like me on a fixed income are getting slaughtered in this economy.
There’s no way I’ll repeat that investment now, no matter where I end up. I can’t afford it unless my HVAC completely fails again, and then who knows if I’ll even be able to replace it?
Anywhere I move now local ordinances that subsidize low income residential HVAC replacements are a necessity. It’s reduced my design space for my next home to such a small parcel that there might not be any homes at all in my price range that aren’t also in a fire or flood zone far from services.
Economic justice isn’t just a slogan. It’s the essence of live itself.
CC&S has been a failure and a fraud from the instant of its inception.
https://www.youtube.com/watch?v=MSZgoFyuHC8&t=284s&ab_channel=thejuicemedia
Cheryl & BJ, I guess I’d offer that CCS ultimate viability remains to be seen.
Is the technology already being held out by some O&G companies and advocates as a panacea? Yes.
Is this tech being used to greenwash. Yes.
Are there some pretty smart people who doubt this tech can ever achieve the net efficiency rate and economics required to justify widespread deployment? Yes.
I’m hesitant to dismiss its potential so decidedly. We’re still pretty early in the development curve. The Utility-scale Renewable Energy picture looked markedly different not so very long ago.
Just a thought…
Pulp Fiction: The European Accounting Error That’s Warming the Planet
https://reports.climatecentral.org/pulp-fiction/1/
Everything old is new again. I strongly recommend all the work being done at ClimateCentral. Just Have a Think (Dave Borlace) and the Financial Times, among others, have good info on various energy resources, and on the credibility of various points of view.
ClimateCentral has also joined the attribution work. This is important.
Thank you Susan. I look forward to reading the report (and will). Climate Central indeed is useful, though I confess I don’t check the site as often as I should. Will add them to my climate/energy front page folder. :)
Hey Susan. Just finished reading “Pulp Fiction.” Started reading during commercials while watching college football, ended up turning the tv off and the radio game broadcast on to focus on the long, yet fascinating read. Ten years old, yet quite interesting.
I know very little about the arguments and research surrounding the utility-scale biomass energy picture here, let alone Europe or elsewhere. I’m now thinking about a number of avenues to be pursued to enlarge my grasp of the issue (such as I’m capable of ;-).
Thank you for the introduction!
“Report: Big businesses are doing carbon dioxide removal all wrong”
https://grist.org/accountability/report-carbon-dioxide-removal-companies/
.
Yeah, I don’t agree with some who claim the technology is already truly viable, it’s not. It doesn’t hold it will never not be though.
Until then, the path forward remains the same. Replace F.F. use in energy production, transportation, agriculture, land use, etc., and as individuals. Reduce the damage additional GHG’ emissions will cause. Mankind has already screwed the planet enough.
My big problem with CCS is thermodynamics.
Except under rather restricted circumstances, it takes more energy to get the CO2 out of the atmosphere and store it than was generated by the combustion that created it. That’s not something you can get around by improving technology, although you will be able to find some small-scale exceptions.
The intractability of the energy balance is why you see a lot of CCS proponents doing a financial balance instead, and suggesting that their process will do better than break-even financially once they make it more efficient.
The only way I see to get enough energy for the capture is to have an essentially free supply of renewable energy that is going begging for a use. This seems unlikely once we have utility scale battery storage and efficient transmission of any excess renewable energy.
in Re to John Pollack, 10 Sep 2025 at 10:14 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839151
Dear John,
I guess that you, in fact, do not speak about “carbon capture and storage” (CCS, a technology for energy production by fuel combustion comprising carbon dioxide capture from effluent gases).
I think so because even though this technology requires significant additional investments in comparison with simply dissipating the flue carbon dioxide into atmosphere and is also less energy efficient because a part (a few %, I guess) of the produced energy is consumed by operating the separation equipment, both these obstacles do represent merely an economical drawback but not a principial technical hindrance in the sense that such a power plant would represent a net “energy sink”.
I therefore suppose that you, actually, spoke about CO2 extraction from the ambient air, which is, due to low atmospheric CO2 concentration, both technically as well as economically much more challenging than CCS. This technology is usuallly called “direct air capture” (DAC).
Unfortunately, hypothetical DAC plants are, at least on the first sight, NOT necessarily energetically unfeasible. As correctly explained e.g. on
https://www.theclimatebrink.com/p/thermodynamics-of-air-capture-of ,
the thermodynamic limit (lowest energy that could be sufficient) for separation 1 kg CO2 from ambient air is about 0.4 MJ (only). This is also quite low in comparison with Gibbs energy of CO2 formation (about 9 MJ/kg).
The above-mentioned theoretical value, however, says nothing about practical DAC feasibility on the required scale.
In fact, reasonably approaching this value on the scale desired for climate change mitigation is indeed practically impossible.
The reason is in the circumstance that thermodynamic values are equilibrium values and approaching these values reasonably thus requires reasonably approaching equilibrium conditions. It requires that involved mass and/or energy fluxes, concentration and/or temperature gradients are infinitesimally small. Translated into practical life, for a finite throughput of a process, such quai-equilibrium conditions can be achieved only at expense of an extremely big size of the respective equipment.
In other words, in practical life, there is any time a trade-off between the size of the equipment (and corresponding investments) on one hand, and reversibility of the process (that is inversely proportional to an extra energy that must be added to the thermodynamically necessary value to reach the desired throughput of the process) on the other hand.
As a result, what really matters is indeed the overall economy (including necessary investments) of the foreseen DAC facilities, not only the energy necessary for operating them at the desired throughput.
Realistic lower limit for overall DAC costs was estimated on the basis of mature industrial processes with technically comparable character, such as noble gas separation from ambient air, and it is very likely higher than 1 USD/kg CO2
https://www.pnas.org/doi/10.1073/pnas.1012253108
In this light, it is quite sad that there are scientists
https://davidkeith.earth/conflict-of-interest-statement/
who, in parallel with their academic career, ran their own “DAC business”. They should be aware that promoting technical/industrial DAC as a solution for climate change mitigation is a scam and assertions that it may become economically feasible due to “innovation” and/or “economy of scale” are lies.
Best regards
Tomáš
Appearing yesterday (Sept. 8, 2025) in Carbon Brief, Dr. Mathew Gidden and Prof. Joeri Rogelj discuss the issue of the actual amount of carbon storage that realistically can be achieved:
.
Guest post: How the role of carbon storage has been hugely overestimated
https://www.carbonbrief.org/guest-post-how-the-role-of-carbon-storage-has-been-hugely-overestimated/
I should have added the following question I’m wondering about:
If the amount of storage volume is indeed only roughly 10% of previous estimates, and thus “only” results in a reduction of 0.4 – 0.7°C, doesn’t this temperature reduction potential make CCS still worth pursuing?
Yes, my thoughts as well on the 0.7 C temperature reduction. That’s 1/2 of the total temperature gain scientists tell us the earth has experience TO DATE! 1/2 is a YUGE deal. And that 0.7 C is likely too small. The potential for CCS is likely far greater than the study indicates. We have been told for decades that oil is running out, we only have xx number of years of oil left. What we have is xx number of years of supply confirmed, next day we go out and explore, and find that much more, and on it goes. Likely same thing with CCS.
It is indeed a You Usually Get Excited deal (but MAR is pithy and I’m usually semi-comatose).
Scientists May Have Identified a Culprit Behind Declining Amazon Rains. Deforestation is playing a greater role than researchers expected, according to a new study. – https://archive.ph/nvkCE
source publication: https://www.nature.com/articles/s41467-025-63156-0
This is not new news, but it covers some of the dynamics of forests and water.
in Re to Susan Anderson, 4 Sep 2025 at 8:26 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838874
Dear Susan,
Thank you very much for this reference. It appears that also human activities different from emissions of greenhouse gases can measurably influence land hydrological regimes.
Although the effect of deforestation contributed mostly (74%) to the observed change in precipitation, while the contribution to the observed change in surface temperature was small (16%), do you still think that my plea to the moderators (for a comment how strongly may climate sensitivity depend on water availability for evaporation from the land) is unsubstantiated and wasting their time?
Best regards
Tomáš
Dear Susan, Thank you very much for this reference. It appears that also human activities different from emissions of greenhouse gases can measurably influence land hydrological regimes.
Nobody questioned THAT, my Dear. What you and other “anything but the GHGs” deniers HAVE to prove is something very different – that we can MASSIVELY INCREASE the land evaporation ENOUGH to mitigate substantial part of AGW.
Given the massive volumes of water required, the short residence time of water in atm. and shortage of EXTRA water available for this purpose (with other uses of water competing and many aquifers already overexploited) neither you, nor JCM could not prove THAT.
in Re to Piotr, 7 Sep 2025 at 3:20 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839002
Hallo Piotr,
Have you considered the arguments comprised in my post of 6 Sep 2025 at 2:20 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838961 ?
I repeat them herein for your convenience:
“First .. it seems to be well possible that the opposite change, namely land switching from a humid hydrological regime into arid one, may be much easier. There already are hints that a such switch can be caused e.g. by forest logging and/or improper agricultural practices promoting soil degradation and erosion.
In other word, no artificial soil drying that would have been comparatively expensive (as the artificial irrigation considered for the opposite switch) seems to be necessary for a “successful” anthropogenic land drainage / desiccation in many regions.
Second, I am afraid that if doubts about practical applicability of supposed research results would have been the sufficient criterion against arranging / starting any specific research, only very few discoveries would have ever happened. In this respect, I think that the difference between a mere assumption that an effect is negligible and a thorough study showing with a decent certainty that the effect indeed IS negligible, is in my opinion quite fundamental.”
For these reasons, I do not see a necessity to prove what you request, namely,
“that we can MASSIVELY INCREASE the land evaporation ENOUGH to mitigate substantial part of AGW”.
This request appears to be rather your straw man that you repeatedly put forward instead responding to arguments of your opponent, or admitting that he might be correct.
Greetings
Tomáš
Tomas Kalisz: “ it seems to be well possible that the opposite change, namely land switching from a humid hydrological regime into arid one, may be much easier”
I didn’t ask you to restate my point in your own words, but to draw the conclusion from it –
since you admit that it is much easier to go from high evaporation to low evaporation than vice versa^* – what does it tell you about the feasibility of the claims by JCM and his source that we can significantly mitigate AGW by massive INCREASES in evaporation?
Tomas: Second, I am afraid that if doubts about practical applicability of supposed research results would have been the sufficient criterion against arranging / starting any specific research, only very few discoveries would have ever happened.
What are you talking about??? What you and JCM are proposing is nothing like financing a theoretical work which practical applications we can’t envision yet. Instead, what you and JCM advocate is something completely different – you push for the _practical_ application THAT WE KNOW WON’T WORK (and you unwittingly admitted as much above), at the EXPENSE of diverting the limited money AWAY from the already existing solution THAT WE KNOW WORKS (GHG reductions).
So no, not the same, not even close. As a saying goes: “They are nailing horseshoes on horses hooves, a frog puts its leg out: Me too”
—–
^* the scheme advanced by JCM requires removing huge swaths of low- and mid-lat land from food production, AND the use of massive amounts of extra water, which we don’t have as the available water is already oversubscribed and/or unsustainably overexploited.
in Re to Piotr, 7 Sep 2025 at 5:37 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839011
Hallo Piotr,
on 2 Sep 2025 at 5:56 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838720 ,
MA Rodger responded to my 1st Sept comment on the August UV thread
https://www.realclimate.org/index.php/archives/2025/08/unforced-variations-aug-2025/comment-page-2/#comment-838689 ,
wherein I wrote
“anthropogenic interferences with water availability for evaporation from the land might have changed climate sensitivity,”
and
“although this topic is potentially relevant for climate science and climate policies, it might have been neglected so far.”
In your comment on MA Rodger, of 2 Sep 2025 at 10:57 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838726
you addressed his observation that
“The potential for significantly “changed climate sensitivity” from declining soil moisture and any resulting potential for AGW mitigation action addressing soil moisture is not something I see looming large in the literature”
by suggesting that it may be because
“there is no feasible “mitigation action addressing soil moisture””.
Thus, you (again, as already happened many times before) attempted to redirect the discussion about absence of a basic knowledge (how much a change in availability for evaporation from the land may influence climate sensitivity) to your straw man topic (that “AGW mitigation addressing soil moisture” may not be practical).
When JCM on 3 Sep 2025 at 9:21 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838792
proposed Zhiyan Zuo et al 2024:
“Importance of soil moisture conservation in mitigating climate change”
https://www.sciencedirect.com/science/article/pii/S209592732400135X
as a hint that climate sensitivity indeed MAY depend on soil moisture, you again skipped the entire content of the ongoing discussion and address solely “mitigating climate change” from the title of the cited article.
Please try to put your straw man in a corner and, for a while, admit that the topic was indeed the relationship between land hydrological regimes and climate sensitivity (and lack of specific studies directed thereto).
It appears that, in fact, you do agree that humans CAN interfere with land hydrological regimes significantly, and it is not excluded that humanity already might have altered them.
If so, and if you put your “impracticality” straw man aside, would you still oppose the idea that studying this yet unknown relationship may be desirable?
Greetings
Tomáš
Tomas Kalisz “Thus, you (again, as already happened many times before) attempted to redirect the discussion about absence of a basic knowledge (how much a change in availability for evaporation from the land may influence climate sensitivity) to your straw man topic (that “AGW mitigation addressing soil moisture”)
You are joking, right? You are attacking me that in my response to the paper titled “ Importance of soil moisture conservation in mitigating climate change” I have addressed what the authors themselves considered THE MOST IMPORTANT part of their paper (so important that they put it in the paper’s TITLE)????
And if this were not enough, you lecture me that instead answering the central point of the paper in question, I should have answered … your point I have ALREADY explained to you “many times before”?
So again: the same as your fellow “anything but GHGs” deniers you propose is to DIVERT the research effort and money AWAY from the climate effects of GHGs and toward the things, that unlike GHGs, we can’t do much about, and which unlike GHGs – are a passive feedback not the AGW driver, and as such their effect is already implicitely included in climate models.
I have told you that “many times before” , but you have been either incapable of understanding, or unwilling to accept as contrary to your a priori beliefs.
Either of these two disqualifies you from any serious discussion.
in Re to Piotr, 11 Sep 2025 at 7:23 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839194
Hallo Piotr,
Thank you for your feedback that seems to reveal some misunderstandings between us.
I will try to address them accordingly.
1) My remark rejecting your comments based on Zhiyan Zuo et al 2024 as a straw man argument
Please note that although the title of the article expressly mentions climate change mitigation, the context in which JCM has cited this article was indeed different, namely the theoretical question regarding climate sensitivity that I address in more detail below.
Shortly, the focus was solely on the “importance of soil moisture conservation”, not on “climate change mitigation”.
For additional comments on this article, especially with respect to its suggestion that under specific pollution scenarios, the soil moisture could be efficiently preserved through Earth afforestation in low and mid latitudes, please refer to my parallel post of 12 Sep 2025 at 12:33 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839213
in the original thread.
2) Your prior explanations (that asking how strong the dependence of climate sensitivity on water availability for evaporation from the land is is an unnecessary harassment of moderators, because the respective physics is already correctly implemented in climate models)
I admit that if you still consider your explanations as correct and suppose that I simply ignore them, you can feel my strawman objection as an unfair accusation.
My explanation why I still think that you may be wrong (and why I rather feel that you might have so far ignored my arguments) has two following parts.
a) I do not doubt that the simulation of the respective physics is already implemented in state-of-art climate models and that this implementation may be basically complete and correct (within broad margin of uncertainties with respect to specific values in the set of parameters characterizing this physics in individual climate models).
b) I assume, however, that although all the respective “water physics” in the models may be basically correct, the difference between the models and the reality may be in the circumstance that there is, actually, NO such fixed set of the parameters (or stable, unchanging functions) characterizing the respective interactions.
In other words, I assume that various models may count with various values of water availability for evaporation from the land, or with various feedback functions characterizing how this parameter will react to changes (such as, e.g., global mean surface temperature rise) caused by “inherent forcings” (such as atmospheric CO2 concentration). From previous discussions on this website I, however, infer that various feedback parameters or functions characterizing the “water physics” (such as lapse rate feedback, water vapour feedback, cloud feedback and like) are considered to be stable characteristics of the existing Earth climate system that basically do not change in time. I suppose that this is also the way how they are implemented into state-of-art climate models.
Otherwise, I could not understand the dispute between proponents of the “conventional” climate models with medium climate sensitivity and the proponents of the “hot” models with high climate sensitivity. It is my understanding that if the feedback parameters or functions were allowed to change in time, the climate sensitivity could not be considered as a time independent parameter anymore, because it is basically a compound product of all these feedback parameters or functions.
Question:
Have I identified correctly that the main difference between our views is in that
A. you still believe that there is one “right” set of feedback functions or parameters that characterize Earth climate and are independent on human activities changing land hydrological regimes, and all that the climate science has to do is to identify the correct values of these parameters or the correct format of these feedback functions, and thus arrive at the correct value of Earth climate sensitivity,
while
B. I rather suppose that human interferences with land hydrology basically prevent that any climate model with fixed feedback parameters or functions characterising the “water physics” could correctly describe past Earth climate and in parallel serve as a reliable tool for future climate projections, because these feedback parameters or functions in fact depend on land hydrological regimes that have ever been and still are being changed by various human activities, and that for this reason, Earth climate sensitivity has changed during Anthropocene and still changes?
Greetings
Tomáš
P.S.
Please note that if your view is right and climate sensitivity is in fact basically insensitive to changes in land hydrological regimes, the modelling study proposed by me should reveal it. That is why I still believe that my question to moderators (if a such study is technically feasible) is quite fundamental and should not be seen as a harassment.
Tomas Kalisz: “Thus, you (again, as already happened many times before) attempted to redirect the discussion about absence of a basic knowledge (how much a change in availability for evaporation from the land may influence climate sensitivity) to your straw man topic (that “AGW mitigation addressing soil moisture”)
Piotr: You are joking, right? You are attacking me that in my response to the paper titled
Importance of soil moisture conservation in mitigating climate change ” I have addressed what the authors themselves considered THE MOST IMPORTANT part of their paper (so important that they put it in the paper’s TITLE)???
Tomas Kalisz: “ Please note that although the title of the article expressly mentions climate change mitigation, the context in which JCM has cited this article was indeed different”
and what does it tell you about your guru, JCM – that he brings up Zuo’s paper AS IF it supported his and your “anything but GHGs” denier agenda, ONLY TO IGNORE THE CENTRAL argument of Zuo’s paper and in fact, according to you, to actively NEGATE IT: (“TK: [JCM] simply does not consider afforestation proposed by the authors of the article as necessary“?
And what does it tell about YOU , that you not only defend the above JCM’s intellectual dishonesty, but you also ATTACKED me for calling the attention to it, by accusing me discussing the CENTRAL point of the Zuo’s paper, is my [repeated] attempt to redirect the discussion ?
A real-life illustration of the saying : “ A thief [points at the just robbed man]: “Stop this thief!“?
In Re to Piotr, 13 Sep 2025 at 9:40 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839261
Dear Piotr,
It appears that you copy-pasted by mistake a text originally intended for another thread, wherein it appeared identically on 13 Sep 2025 at 9:43 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839262
If the right text that you prepared as the reply to my post of 12 Sep 2025 at 4:13 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839224
is still waiting as a result of this mistake, I am looking forward to read it in the next moderation round.
Greetings
Tomáš
Tomas Kalisz 13 Sep 4:55 PM
” In Re to Piotr, 13 Sep 2025 at 9:40 AM, Dear Piotr, It appears that you copy-pasted by mistake a text originally intended for another thread, wherein it appeared identically on 13 Sep 2025 at 9:43 AM,”
What are blabbering about? My 9:40AM post was NOT posted “by mistake” and was NOT “intended for another thread” – it was posted in the CORRECT thread: IMMEDIATELY BELOW your post from 12 Sep 4:13 PM to which it referred and which WORDS my 9:40 AM reply QUOTED:
============= Piotr, 13 Sep 2025 at 9:40 AM =============
Tomas Kalisz [12 Sep 4:13 PM] “ Please note that although the title of the article expressly mentions climate change mitigation, the context in which JCM has cited this article was indeed different”
and what does it tell you about your guru, JCM – that he brings up Zuo’s paper AS IF it supported his and your “anything but GHGs” denier agenda, ONLY TO IGNORE THE CENTRAL argument of Zuo’s paper and in fact, according to you, to actively NEGATE IT: (“TK: [JCM] simply does not consider afforestation proposed by the authors of the article as necessary“?)
And what does it tell about YOU, that you not only defend the above JCM’s intellectual dishonesty, but you also ATTACKED me for calling the attention to it, by accusing me that my discussing of the CENTRAL point of the Zuo’s paper, is my [repeated!] attempt to ,,, redirect the discussion ? A real-life illustration of the saying : “ A thief [points at the just robbed man]: “Stop this thief!“?
===================== end of my 9:40 AM post =====================
So instead of pretending that the above questions didn’t apply to your QUOTED claim 12 Sep 4:13 PM – grow a pair, stop looking for excuses, and answer these questions.
in re to Piotr, 14 Sep 2025 at 10:04 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839300
Dear Piotr,
No, I really have not found in your text of 13 Sep 2025 at 9:40 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839261 ,
any hint that it addresses the content of my post of 12 Sep 2025 at 4:13 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839224 .
That is why I thought that you introduced this completely irrelevant text from another thread by mistake. If you do not think that my posts deserve reading, why are you responding thereto?
Deliberately loading the forum with noise is a trolling practice you have many times criticised yourself.
Best regards
Tomáš
TK: It’s not new, just an update with further scientific confirmation.
Please do not reply.
This morning’s N.Y. Times with the latest on Trump’s efforts to stupidly force ceasing operation or destroying the two satellites that makeup the valuable Orbiting Carbon Observatory mission:
.
Two Valuable Satellites Are in ‘Perfect Health.’ They May Be Scrapped.
The Trump administration wants to switch off and possibly destroy the climate-monitoring technology.
By Sachi Kitajima Mulkey
.
https://www.nytimes.com/2025/09/05/climate/trump-climate-satellites.html
Unpaywalled link: https://archive.ph/hxi1x
It’s beyond stupid, it is hostile and dangerous. I think I posted an ‘insider’ response saying they plan to burn it a while ago.
Authoritarians and propagandists really hate instruments that provide data they cannot edit before being made public. They would far rather pollute the information environment as much as possible in every way possible.
As we see here in our tiny neck of the woods and far more so on a national and international scale.
What the trump administration is doing with those satellites (and most of their other climate, economic and social policies etcetera,) is pure idiocy. Never seen a government in a developed country do so many idiotic things. Totally leaves me stunned.
With September a week old, the 2025 Atlantic hurricane season should be in full swing. But factors appear to be defying the predictions of an ‘above normal’ season, even the latest one (NOAA 7th Aug). Except for Hurricane Erin which churned its way up the Atlantic and contributed the lion’s share of the season ‘score’ for the end of August of ACE=39.4, things had been rather quiet.
Through last week a single disturbance nudging its way across the tropical Atlantic towards the Caribbean was looking like it might be the start of a change with the season getting into its swing. But the recent forecasted 90% chance of storm formation expected by now has been reduced longer-term to 30% with “a drier air mass (is) preventing further development over the next couple of days” and conditions less favourable thereafter.
With no further disturbances yet to show up, the traditional height which should make the Atlantic hurricane season ‘above normal’ is rapidly running past.
Atlantic hurricane are only one item in the global tropical storm cycle. And tropical storms are a small part of the global circulation which produces extreme (or not extreme) weather events. They are ‘exciting’ but they are, especially if you limit your observations to one year, an extremely limited reflection of changes in the system as a whole.
Also, events do not equal systems.
This should be obvious. Why isn’t it?
Susan Anderson,
To answer you question – A hurricane is indeed “an extremely limited reflection of changes in the system as a whole**. Also, events do not equal systems.” You ask “This should be obvious. Why isn’t it?”
It is indeed obvious that systemically a sub-system is not characteristic of its system. Yet understanding of systems theory is pretty rare.
(**As well as huffing & puffing and blowing homes down, tropical storms do other stuff. I did once look at how much energy hurricanes & other storms pumped up to the upper troposphere and I found it wasn’t much different to the amount of energy pumped up there by atmospheric cells. Probably insignificant given the size of ΔOHC, tropical storms also churn up the seas with smaller storms pulling heat out of the shallow oceans but with the big ones mixing heat into the deeper oceans.)
On the subject of Atlantic hurricanes under climate change, the prevelence of distructive Atlantic hurricanes are considered by many (who should perhaps know better) as indicative of the true threat posed by AGW. As an instance of that, I cannot imagine hurricane-researcher Judith Curry suffering her “confusionism and denialism” if the strength of the 2005 season had become the norm post-2005. And as another example, periods with an absence of destructive hurricanes making a US land-fall have been used by denialists to trivialise AGW, despite this being a very variable metric.
So the Atlantic hurricane season is on the climatology agenda, which is why I post significant news of it here at RC.
The 2025 season has become a very unusual season, especially as the season has been forecast as something a lot different.
A few other web-commentaters have also noted the strange inactivity (eg
HERE and HERE).
And with the NOAA NHC outlook now showing no cyclone activity expected up to mid-September, that’s a gap of 18 days with zero storms slap-bang in mid-season. Even weak seasons of late (eg 2015, 2014, 2013, 2009) saw nothing like this.
Apparently, forecasters say they are expecting the back end of September to be business as usual. So signs of that should appear in coming days, coz there ain’t that many weeks in the month.
Things like this were said last year when we had a powerful category 5 hurricane in early July (Beryl) then little until the second week in September. This was followed by a huge upswing in activity that was just enough to push the ACE index into a hyper-active season (admittedly only just). This year has some parallels so far, a powerful category 5 hurricane (Erin) fairly early but little else even as we approach peak season. With above-average tropical Atlantic SST’s and cool-neutral ENSO conditions, it is still possible 2025 could again be a hugely backloaded season if whatever is putting a lid on activity recedes. It’s not over until it’s over.
Adam Lea,
The 2024 season entirely failed to register in my comparisons but it does present a good comparison. I’m surprised I wasn’t flapping as much about the situation back then, (My surprise prompted a check in the RC archives.)
There were two gaps last year, 25 days following Beryl through July and 19 days between Ernesto and Francine Aug 20th to Sept 8th. This second gap is almost a match to the situation today..
As for the ‘why?’, the wind shear and Saharan dust being ‘blamed’ for the absence of storms are not unusual causes. But I don’t recall “dry air” being given before as the reason, although apparently it is a thing (number 5 here).
And the forecast here is that adverse conditions will end soon. “The dry air and Saharan dust should start to clear out of the Atlantic main development region this weekend,” DaSilva added. “Atmospheric conditions that are conducive to tropical development are expected to return in the second half of the month” … while off the southern Atlantic Coast of the United States, “a cold front could spin up tropical development this weekend or early next week,” DaSilva said.
The past couple of years really have me doubting the utility of these annual Atlantic basin TC outlooks.
I accept that they do show some skill, especially relating to ENSO phase and ocean temperature. However, these rather large unexpected gaps in what are initially forecast to be active seasons suggest that there needs to be more research focus on the predictability of the dry air/African dust intrusions, too. Of course, that’s part of the point of doing a forecast – to show where you’re falling short and need more research.
The forecasts attract a lot of media attention, which generates negative consequences especially for a weak forecast. They undermine the credibility of hurricane forecasts in general, because in the public mind there is often little distinction between forecasts issued NHC for specific storms (which are very good) and the seasonal outlooks. They generate negative headlines throughout the season when people receive repeated “nothing happening now, but just wait…” messages. Add to that, the public confusion about hurricane incidence as a supposed indicator of AGW, and you end up with an overall message that the weather scientists don’t know what they’re talking about, with weekly updates that the (TC incidence) forecast is still failing.
The seasonal hurricane outlooks do offer a useful hook to talk about TC safety at the beginning of the season. However, there are better ways to do this. In particular, they don’t offer a distinction between overall storm numbers and landfalling storms. They exclusively focus on the storm intensity classification based on peak windspeed anywhere in the storm at any time. This neglects other hazards such as flooding rains, storm surge, rip tides, embedded tornadoes, etc. that are only loosely tied to peak windspeed. This also obscures the message that the worst hazards associated with TCs are from the water, not the wind.
Seasonal hurricane forecasts are based on teleconnections between various large scale fields that are predictable months in advance, and both TC numbers and ACE index. These teleconnections have a sound physical basis as to why they exist and are usually incorporated into a statistical regression model built over several decades of data.
These climate teleconnections do influence upcoming hurricane seasons overall but intra-seasonal factors such as Saharan air outbreaks, TUTT development over the tropics and interaction between the tropics and mid-latitudes can cause lulls even within active seasons. 2024 is a good example of where the inter-tropical front moved northward of its climatological position resulting in easterly waves exiting Africa further north than normal into much more hostile conditions, causing a surprising lull in activity during August and much of September, despite very warm tropical Atlantic SSTs and cold-neutral ENSO conditions. These intra-seasonal factors are not predictable months in advance and are essentially random noise super-imposed on the signal. The same goes for landfalling tropical cyclones which depend on how the steering winds are aligned at the time a storm is active, which itself is heavily influenced by the position of ridges and troughs over the ocean. This is also largely random although there is a modest positive correlation between overall seasonal activity and landfalling activity, but even for landfalling hurricanes, it depends a lot on where it makes landfall (i.e. how much stuff is there in the path of the core to be impacted). The seasonal forecasts nonetheless do have some use in making better decisions within the (re)insurance sector as demonstrated here:
https://www.eurotempest.ltd/wp-content/uploads/Using-TSRs-Seasonal-Forecasts-to-Generate-Alpha-For-Insurance-Linked-Strategies.pdf
As I said, the seasonal tropical cyclone forecasts show some skill. Your citation backs that up by showing that they are useful for setting probabilities for the reinsurance industry. I just don’t think it’s enough to justify the large amount of publicity they get at the beginning of each season. They aren’t improving public safety, unlike storm-specific forecasts.
I believe that they are weak forecasts that end up providing easy fodder for the denialists when they overestimate the storm incidence.
Karsten V. Johansen: “A market economy without any state intervention will never be able to solve the problem with CO2 emissions.”
Thank you Captain Obvious That’s why, other than deniers, nobody advocates “A market economy without any state intervention”
KVJ: ” The traditional way with carbon taxes is politically unviable, because the majority with low incomes get to care the whole burden of the tax”
I am not sure what you wanted to express by “the traditional way”, but if you mean the only politically feasible “revenue-neutral carbon tax”, as advocated by William Nordhaus who got for it a 2018 Nobel Prize in Economics (being from Norway, you heard about Nobel Prize, right?) and, as implemented for several years in Canada,
As discussed on RC in the past – the OPPOSITE to what you claim is true – “the majority with low incomes” not suffered most, but BENEFITED most, because their refund (equal per household) was LARGER than the tax they paid (proportional to the use, and low income people use LESS fuel per capita than rich people). As a result, 80% of Canadian rebate was larger than tax they paid
The fact that we no longer have that tax in Canada is the testament to the post-truth politics and the power of the social media algorithms – Pierre Poilievre, Canadian right-wing populist, modelling his campaign after Trump – managed to cynically manipulate the majority of the Canadians into believing his/your claim that – ” the majority with low incomes get to care the whole burden of the tax “, even having spent his adult life in politics, who KNEW he was running on a lie.
That you uncritically repeat the same falsehood as a right-wing politicians modelling himself on Trump – does not surprise – les extremes se touchent….
Piotr, you manage to distort what I wrote (and have written here on this site a whole lot of times) to the complete opposite. I don’t understand how that’s possible, to misunderstand me so completely, unless your aim is exactly that: to distort what I write.
*I am for James Hansen’s proposal of carbon fee and dividend*, that’s what I wrote, and as said above have before written that a lot of times here on this site. I translated a great article of his, about his proposal, into norwegian in 2012. It was published in the journal “Vardøger”. See https://naturvernforbundet.no/hordaland/hvorfor-karbonavgift-til-fordeling/ – “karbonavgift til fordeling” is norwegian for “carbon fee and dividend”. The norwegian title of the article means: “On the necessity of a carbon fee and dividend”. (The text inserted in the end: “Artikkelen er oversatt av Karsten Johansen med godkjennelse fra James Hansen. Den har også stått på trykk i Vardøger 35 og er gjengitt med tillatelse.” means “The article is translated into norwegian by Karsten Johansen with the approval of James Hansen. It has also been printed in Vardøger nr. 35 and is here published with approval” (meaning: by the journal – the site is the local official site for the district “Hordaland” of the norwegian nature conservation association. This organization has (on the national level) adopted carbon fee and dividend as it’s official policy, which I of course support).
Regarding William Nordhaus: if he agrees with James Hansen’ proposal, that’s exellent. I haven’t seen him argue for that, but that could of course be my fault. Please correct me if am wrong, but please also: with exact references to where and when.
The critique of Nordhaus’ economic estimate of the proportions of the climate threat, written by the heterodox economist Steve Keen, is that Nordhaus, according to Keen, grossly underestimates how deeply serious the problem is, how enormous it’s economic (and thus: social) proportions are:
“However, this analysis commenced from the perspective, stated in the very first reference in this tradition (Nordhaus, 1991), that climate change is a relatively trivial issue:
“First, it must be recognised that human societies thrive in a wide variety of climatic zones. For the bulk of economic activity, non-climate variables like labour skills, access to markets, or technology swamp climatic considerations in determining economic efficiency.” (Nordhaus, 1991, p. 930; emphasis added).
If there had been a decent evaluation process in place at this time for research into the economic
impact of climate change, this paragraph alone should have raised alarm bells: yes, it is quite likely
that climate today is a less important determinant of ‘economic efficiency’ today than ‘labour skills,
access to markets, or technology’, when one is comparing one region or country with another today.
But what is the relevance of this cross-sectional comparison to assessing the impact of drastically altering the entire planet’s climate over time, via the retention of additional solar energy from additional greenhouse gases?
One sentence further on, Nordhaus excludes 87% of US industry from consideration, on the basis
that it takes place ‘in carefully controlled environments that will not be directly affected by climate
change’:
“Table 5 shows a sectoral breakdown of United States national income, where the economy is subdivided by the sectoral sensitivity to greenhouse warming. The most sensitive sectors are likely to be those, such as agriculture and forestry, in which output depends in a significant way upon climatic variables. At the other extreme are activities, such as cardiovascular surgery or microprocessor fabrication in ‘clean rooms’, which are undertaken in carefully controlled environments that will not be directly affected by climate change. Our estimate is that approximately 3% of United States national output is produced in highly sensitive sectors, another 10% in moderately sensitive sectors, and about 87% in sectors that are negligibly affected by climate change”. (Nordhaus, 1991, p. 930; emphasis added).
The examples of ‘cardiovascular surgery or microprocessor fabrication in ‘clean rooms’’ might seem
reasonable activities to describe as taking place in ‘carefully controlled environments’. However,
Nordhaus’s list of industries that he simply assumed would be negligibly impacted by climate change is so broad, and so large, that it is obvious that what he meant by ‘not be directly affected by climate change’ is anything that takes place indoors – or, indeed, underground, since he includes mining asone of the unaffected sectors. Table 1, which is an extract from Nordhaus’s breakdown of economicactivity by vulnerability to climatic change in US 1991 $ terms (Nordhaus, 1991, Table 5 p. 931).Since this was the first paper in a research tradition, one might hope that subsequent researchers challenged this assumption. However, instead of challenging it, they replicated it. The 2014 IPCC Report repeats the assertion that climate change will be a trivial determinant of future economic performance:
“For most economic sectors, the impact of climate change will be small relative to the impacts of other drivers (medium evidence, high agreement). Changes in population, age, income, technology, relative prices, lifestyle, regulation, governance, and many other aspects of socioeconomic development will have an impact on the supply and demand of economic goods and services that is large relative to the impact of climate change”. (Arent et al., 2014b, p. 662) It also repeats the assertion that indoor activities will be unaffected. The one change between Nordhaus in 1991 and the IPCC Report 23 years later is that it no longer lumps mining in the ‘not really exposed to climate change’ bracket (Nordhaus, 1993).2 Otherwise it repeats Nordhaus’s assumption that anything done indoors will be unaffected by climate change:
“FAQ 10.3 Are other economic sectors vulnerable to climate change too?
Economic activities such as agriculture, forestry, fisheries, and mining are exposed to the weather and thus vulnerable to climate change. Other economic activities, such as manufacturing and services, largely take place in controlled environments and are not really exposed to climate change”. (Arent et al., 2014b, p. 688; emphasis added).
All the intervening papers between Nordhaus in 1991 and the IPCC in 2014 maintain this assump-
tion: neither manufacturing, nor mining, transportation, communication, finance, insurance and
non-coastal real estate, retail and wholesale trade, nor government services, appear in the ‘enumer-ated’ industries in the ‘Coverage’ column in Table A1. All these studies have simply assumed that these industries, which account for of the order of 90% of GDP, will be unaffected by climate change. There is a ‘poker player’s tell’ in the FAQ quoted above which implies that these Neoclassical economists are on a par with United States President, Donald Trump, in their appreciation of what climate change entails. This is the statement that ‘Economic activities such as agriculture, forestry, fisheries, and mining are exposed to the weather and thus vulnerable to climate change’. Explicitly, they are saying that if an activity is exposed to the weather, it is vulnerable to climate change, but if it is not, it is ‘not really exposed to climate change’. They are equating the climate to the weather.
While this is a harsh judgment to pass on fellow academics, there is simply no other way to make
sense of their collective decision to exclude, by assumption, almost 90% of GDP from their enumer-
ation of damages from climate change. Nor is there any other way to interpret the core assumption oftheir other dominant method of making up numbers for their models, the so-called ‘statistical’ or
‘cross-sectional’ method.” (Keen, p. 4-5 in this paper https://mahb.stanford.edu/wp-content/uploads/2021/07/The_appallingly_bad_neoclassical_economics_of_clim-1.pdf ).
But maybe Nordhaus has changed his mind about this? If so, again: please be so kind to show where and when, with exact references/links etc.
Karsten V. Johansen Piotr, you manage to distort what I wrote to the complete opposite
*I am for James Hansen’s proposal of carbon fee and dividend” .
Then you should work on your delivery, since your
KVJ: “The traditional way with carbon taxes is politically unviable, because the majority with low incomes get to care the whole burden of the tax””
uses the same strawman deniers use discredit the actually-implemented carbon taxes by dishonestly painting them as a tax grab placing the whole burden onto the poor.
It’s strawman – because nobody serious is proposing the “non-dividend” carbon tax for the OBVIOUS reasons:
P: “ the only politically feasible form of carbon tax is the “revenue-neutral” tax, as advocated by William Nordhaus, and, as implemented for several years in Canada, under which “the majority with low incomes” not suffered most, but BENEFITED most, because their refund (equal per household) was LARGER than the tax they paid (proportional to the use, and low income people use LESS fuel per capita than rich people). ”
KVJ: “Regarding William Nordhaus: if he agrees with James Hansen’ proposal, that’s exellent.”
Are you 100 % sure that this shouldn’t read: “Regarding James Hansen’ – if his proposal agrees with William Nordhaus’ STUDIES and MODELLING of the carbon tax, that’s excellent.”.
KVJ: “The critique of Nordhaus’ economic estimate of the proportions of the climate threat, written by the heterodox economist Steve Keen, is that ”
Your brain is drifting away on a tangent again. What Nordhaus’ estimates of the effect of climate change on different sectors of economy have to do with the subject of this discussion (revenue-neutral carbon tax)?
KJV: “ But maybe Nordhaus has changed his mind about this?”
On his revenue-neutral carbon tax modelling? Why should he?
Re nigelj (CC KVJ)
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839063 Thank you; (re my “ I wondered if maybe KVJ was referring to cap-&-trade there.” @ https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839045 ( in re https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838970 )
I was referring to the version which KVJ labelled as “The traditional way with carbon taxes is politically unviable” https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838814 )
Excellent article by Michael Mann and Peter Hotez in today’s (tuesday sept. 09, 2025) edition of The Guardian: https://www.theguardian.com/commentisfree/2025/sep/09/science-under-siege-weaponised-disinformation-michael-mann-peter-hotez :
“There are five primary, interconnected forces behind the assault on science and reason. We call them the “five Ps”: the plutocrats, the petrostates, the pros (eg paid promoters of anti-science), the propagandists and – with important exceptions – the media. Together they have generated a perfect storm of antiscientific disinformation that now threatens humanity.
A nefarious web of actors including plutocrats in the US and Australia, along with libertarian tech bros, and petrostates such as Russia and Saudi Arabia fund and amplify deceitful, ideologically motivated antiscience. They collectively employ weaponised social media outlets, podcasts and rightwing cable news broadcasts as their preferred tools. The objective is to inundate the public with fossil fuel-friendly propaganda that undermines climate action or public health measures including vaccinations. Scientists are often portrayed as enemies or villains. The well of public opinion so critical to informed voting is poisoned. (…)”
I find especially the following very central as to the question: what is causing the steadily growing anti-scientific sentiment and the recent degeneration of democray and government in the US:
“In the US, partisan districting (“gerrymandering”), low voter turnout and a polarised two-party politics that squeezes out moderates have combined to yield electoral representation that is at odds with the actual views of the people. For example, a Gallup poll from last year found that 61% of US adults were concerned about the climate crisis. Yet US policies are currently set by a party that denies the basic existence of climate change.
While there is a modest move in some states towards ranked choice voting, substantial changes in the American electoral system, such as compulsory voting, are unlikely to happen in the near term. A more viable way forward involves attacking the problem at its source: the well-organised and financed antiscience disinformation machine.
In April 2021, Mike was among a number of witnesses, including former prime minister Malcolm Turnbull, who spoke out against the Murdoch disinformation machine during an Australian Senate media diversity inquiry. Later that year, Labor and Greens called for an official inquiry into the “dangerous monopoly” of the Murdoch media empire. Biennial assessments monitoring media diversity are now under way, with the first report issued earlier this year.
The Australian Broadcast Corporation also took on the Murdoch empire, re-broadcasting a two-part documentary series Fox and the Big Lie over the vociferous objections of the Murdochs.”
The only thing I really miss in this, is James Hansen’s proposal: carbon fee and dividend. It was among nations first adopted by the state British Columbia in western Canada in 2008, and eleven years later in the whole of Canada by the government of Trudeau in january 2019 (unfortunately it was rolled back after the last election in Canada, which again reinforces what – as cited above – is said about the forces behind the ongoing assault on science and reason from oligarchs/plutocrats, petrostates, media etc.: “the nefarious web of actors”.
As once in the seventies written by the well-known political dissident, democrat and excellent poet and singer from the stalinist/communist former East Germany, Wolf Biermann (he was for many years in house-arrest in his flat in Eastern Berlin, until the regime under Erich Honecker threw him out in 1976 during a concert-tour of his in West Germany): “Freedom does never arrive too soon. It does not come from a good night’s sleep”.
“…a polarised two-party politics that squeezes out moderates…”
Not a good characterization of the US political scene, unless you include the complementary observation that the unbridled influence of truly obscene amounts of money, strategically directed in multiple arenas–media, education, and law, notably–have shifted the Overton window in US politics far, far to the right. At least one cabinet-level official in the Trump Maladministration is a congregant of a church that advocates restricting voting to males, for example.
Meanwhile, Democratic positions on most issues are actually more conservative than they were in 1970. (The exceptions being the culture war stuff, which is reflective of social change generally.)
It’s true that the increasingly severe impediments to aspiration consequent to the stagnation of middle class and working class incomes are radicalizing some folks, especially younger adults. But to a considerable extent, the middle is still where most Americans are. Their views are not, however, directing policy, or driving political positions effectively, mostly due to the efforts of the extremist right-wing bloc.
Mea culpa: that last comment of mine fails to acknowledge that KVJ’s comments made some of the main points as well. I responded, I admit, hastily.
KVJ, On the observation “In the US, partisan districting (“gerrymandering”), low voter turnout and a polarised two-party politics that squeezes out moderates have combined to yield electoral representation that is at odds with the actual views of the people.”
In the U.S., I firmly believe that the incredible level of gerrymandering occurring is a major forcing, with the resulting polarization being one of the primary feedbacks (the other major forcing is the ocean of money that Kevin discusses).
In the majority of our states redistricting is not done by a independent apolitical committee free from political pressure, but by state legislatures. So with politicians setting district boundaries, the end result is predictable.
In too many districts, gerrymandered to the point that only one party’s candidate will typically win the general election, getting through that party’s primary election is all that matters. Thus the increasing polarization, decreased voter interest, etc. that result.
Moderates, as Kevin ably notes, is still where the majority of Americans consider themselves to belong. Both the D and R party know this, but repeatedly gerrymander anyway in states that don’t have neutral redistricting rules.
Until Americans are fed up enough with gerrymandered predetermined outcomes and mountains of money used to essentially buy powerful influence on politicians, I’m afraid elected moderates will remain far fewer relative than the number of moderate Americans would suggest.
I’ve pretty much given up on any reform of that sort ever happening in the US. Bolivar was speaking of South America, but it applies equally to the US: “America is ungovernable. He who tries plows the seas.”
If we can’t solve the social media fueled fragmentation of our populace now and going forward, saving our children and their children from this world we allowed to be made, then, yeah Ray, you’re probably right.
Ray, YMMV, but I cling to a shred of hope. Other people’s pithy words come to my mind also:
You can fool some of the people all the time… (at. A. Lincoln, inter alia: quoteinvestigator.com/2013/12/11/cannot-fool. Warning: time sink!) That’s been amply demonstrated: even as I type, I fool myself.
…and you can fool all the people some of the time… (“Lincoln”). Hmm, close enough to true. There’s always a few obstinate holdouts, who may be fooled by someone else..
…but you can’t fool all the people all the time. (“Lincoln”). Plenty of wannabe kings have tried, but they all turned out to be fooling themselves eventually. Practically speaking, it comes down to “for how long?” And “how?” Which leads me to:
You can fool a governing plurality of the people long enough to cause global damage, if you’ve got enough money (yours truly). Sufficiently qualified AFAICT, but not exactly pithy. Probably why I’m not POTUS [nah, that’s not it -MA].
I dispute, however, that the US is “ungovernable”. The Koch club (a synecdoche) appears to have things well in hand at present, for the purpose of extracting as much profit from the globe as they can while civilization collapses around their ears. As hard as it is to believe, for now they’ve got a governing plurality of we, the people, and IMHO things aren’t very encouraging in the near term. But they’re at least faintly encouraging, and I’ve seen a lot happen in 30 years.
East Asian aerosol cleanup has likely contributed to the recent acceleration in global warming
We find a rapidly evolving global, annual mean warming of 0.07 ± 0.05 °C, sufficient to be a main driver of the uptick in global warming rate since 2010. We also find North-Pacific warming and a top-of-atmosphere radiative imbalance that are qualitatively consistent with recent observations. East Asian aerosol cleanup is thus likely a key contributor to recent global warming acceleration and to Pacific warming trends.
https://www.nature.com/articles/s43247-025-02527-3
“Two-thirds of the global warming since 2001 is SO2 reduction rather than CO2 increases,” says Peter Cox at the University of Exeter in the UK.
an analysis of CERES data from 2001 to 2019 by Cox and Margaux Marchant, also at Exeter, suggests the biggest factor is that clouds are becoming darker.
https://www.newscientist.com/article/2487992-most-warming-this-century-may-be-due-to-air-pollution-cuts/
Well for sure something happened in 2010. Teleconnections, big forest fires and torrential rain dopped the ocean level so much it’s seen as a unique wart on the SLR plots. Something(s) changed then. I suspect Jim Hansen’s +0.36/decade 2012-2025 S.B, whatever linear, if you must go linear, from 2010 not 2012.
Mo Yunus 8 Sep quoting Samset et al, 2025 “East Asian aerosol cleanup has likely contributed to the recent acceleration in global warming […] sufficient to be a main driver of the uptick in global warming rate since 2010”
Which means that “the recent acceleration in global warming” is NOT a permanent increase in the AGW rate, but rather a transient effect – corresponding to the short period of rapid East Asian aerosol cleanup after 2012. The cleanup which according to your source (Fig. 1 c) – pretty much has run its course – the East Asia’s So2 emissions level off in early 2020s, and once all ships run on low-sulfur fuel – so will the ships SO2 emissions. Thus “the main main driver of the uptick in global warming” either already is, and soon will be, gone.
This in turn means – that the models may have underestimated warming 2012-23 – not “because clouds aren’t well represented in today’s climate cmip models”, but because the models didn’t not have the actual aerosol forcing – couldn’t know that East Asia would reduce aerosols as sharply as they did.
But now with the SO2 emissions levelling off – this source of discrepancy between models and observations – will be greatly reduced/gone. And with it – the hopes of denialists for the (permanent) AGW acceleration, pinned on Hansen.
Interesting article examining five polar geoengineering concepts and written in an approachable way has been published in the journal Frontiers in Science:
.
Safeguarding the polar regions from dangerous geoengineering: a critical assessment of proposed concepts and future prospects
Siegert M, Sevestre H, Bentley MJ, Brigham-Grette J, Burgess H, Buzzard S, Cavitte M, Chown SL, Colleoni F, DeConto RM, Fricker HA, Gasson E, Grant SM, Gulisano AM, Hancock S, Hendry KR, Henley SF, Hock R, Hughes KA, Karentz D, Kirkham JD, Kulessa B, Larter RD, Mackintosh A, Masson-Delmotte V, McCormack FS, Millman H, Mottram R, Moon TA, Naish T, Nath C, Orlove B, Pearson P, Rogelj J, Rumble J, Seabrook S, Silvano A, Sommerkorn M, Stearns LA, Stokes CR, Stroeve J and Truffer M. Safeguarding the polar regions from dangerous geoengineering: a critical assessment of proposed concepts and future prospects. Front Sci (2025) 3:1527393. doi: 10.3389/fsci.2025.1527393
https://www.frontiersin.org/journals/science/articles/10.3389/fsci.2025.1527393/full
.
Anything but living differently… which means no solutions at all.
Re https://www.realclimate.org/index.php/archives/2024/09/phantastic-job/ :
“How We Study Earth’s Ancient Temperature & Why It’s Changed So Much- ft.@ClimateAdam” GEO GIRL https://www.youtube.com/watch?v=3GcS55X4epw
&
“What 500 Million Years of Climate Clues Mean for Our Future | ft. @GEOGIRL” ClimateAdam https://www.youtube.com/watch?v=jmrO_nGYrhE&t=1s
“Joe Rogan Doesn’t Understand Graphs” Climate Town https://www.youtube.com/watch?v=r1bMJekCiBw
“Joe Rogan Misinterprets Important Scientific Study So Badly That Its Author Steps in to Correct Him” https://www.msn.com/en-us/news/technology/joe-rogan-misinterprets-important-scientific-study-so-badly-that-its-author-steps-in-to-correct-him/ar-AA1M82Jg?ocid=msedgntp&pc=U531&cvid=68bf59db83124f08bcd94bbc9e92ca2e&ei=10
Hoping the meeting happens.
Also:
“History of the Earth” Algol https://www.youtube.com/watch?v=Q1OreyX0-fw
I suspect/believe the Paleoproterozoic Snowball was *not* 300 Myr long as shown there; see:
Steven Baumann:
“Geo-Files: The Real History of the Huronian Glaciation (S6-E5, V.2)” https://www.youtube.com/watch?v=bpIQhClkWcA ,
“Geo-Analysis of PBS’s Eons Episode on the Huronian Supergroup” https://www.youtube.com/watch?v=noAcJU6_Iik&list=PL2EQjg5MS7nUrNhG-2M-JUBdShpITXmlZ
(note Steven Baumann is more skeptical of the Snowball Earths than some others, apparently. I had read about the evidence and theory and remember finding the case quite convincing – maybe even for the Paleoproterozoic one, *but* that was 20 years ago, and I’m not a geologist.)
Thanks Patrick for the Joe Rogan story. I’m quite pleased that Jessica Tierney is more than willing to go on Rogan’s show in an attempt to explain to him his rather blatant misconstrued eyesight. And expose his huge audience to a little climate science. I think I will even call his show and put in my two cents suggesting “why not?” (with dose of Joe praise thrown in ;-)
Though not a popular idea amongst several (almost all?) here in RC comment land, I wish and hope for more interaction of climate scientists and activists with those in social media because of the audience sizes these programs reach. Too many Americans are caught in too many self-reinforcing bubbles. And who doesn’t enjoy popping bubbles?
re David – You’re welcome, and Thank you too.
I understand the reticence about red team/blue team debates (which may seem more like a sports event?…
(with the rules ie. 2 min. for rebuttal or whatever. It depends on the nature of the audience, of course; a bunch of philosophy students engaged in some discussion where the goal is to understand…),
… but this is/would be (hopefully) a different sort of engagement. (Reaching out to attempt to set the record straight seems like a generally good idea. Although I did see a video in which Rebecca Watson did argue that trying to do so with Rogan is not such a good idea, but that might apply more to people calling in? (I don’t completely remember))
Other forms: lawyers arguing a case (like debating but…), or writing a series of letters back and forth…
“And who doesn’t enjoy popping bubbles?” – Yes, Totally!
Warming Seas Threaten Key Phytoplankton Species That Fuels the Food Web.
Apparently, Prochlorococcus is currently responsible for about one fifth of the planet’s oxygen and one half of the food in tropical seas.
Thanks Steven, it’s an interesting and scary report. In a way, it reminded me of the bit in the movie ‘Interstellar’ where one of the characters says something about being the last left on Earth to a fate of starving and suffocating.
A couple of recent comments touch on the Canadian carbon tax. Just to clarify, the recent rollback by the Carney government is partial, not total: the “consumer-facing” carbon tax had become massively unpopular, and was axed. However, carbon pricing still applies at the industrial level. “A price on pollution for large emitters will continue to be a pillar of Canada’s plan to build a strong economy and greener future.”
You can read more at the link below, but trigger warning: it appears to have an unusually strong complement of political spin bulking up the factual bits. To my ear at least, it gives a bit of the old “doth protest too much” flavor.
https://www.canada.ca/en/department-finance/news/2025/03/removing-the-consumer-carbon-price-effective-april-1-2025.html
Still, I’m sure it’s better than axing the whole carbon-pricing initiative.
On a related note, the Carney government also at least partially caved to the legacy automakers, lengthening the timeline on the EV mandate, and putting the whole policy under review:
https://www.cbc.ca/news/politics/carney-ev-mandate-pause-1.7625992
Climate data is becoming difficult to find. I’ve had two localized ocean oscillation mode indices and a volcanic search engine go stale.
I managed to get the NPGO index restored with a polite request for an update, but ENSO MEIv2 updates have missed two months in a row and I didn’t get any response to my request for an update.
The NOAA addresses seemed to work okay, but the Japan address failed:
:
No mx record found for domain=met.kishu.go.jp
Next month I’ll be falling off the end of available time series data if ENSO is not updated for a third month in a row. I’ve estimated 3 months delay from ENSO index to its global effects. Once that slack is gone, my plot updates cease. There’s no way I can generate any additional time series without the most critical independent variable for my multivariable linear regression.
The Smithsonian’s volcanism project search engine has been offline for months. I can’t seem to download and open the CSV file they provided in lieu of the search engine. Although I don’t need updated volcanic data to generate extended time series plots, the new plots I publish may be out of date in terms of new volcanic influences.
Unless data access improves, this may be the last month I can publish an updated time series plot from my amateur model.
I’ve tried since October to surmise an alternate explanation for the unexplained portion of 2023 warming, but every attempt didn’t pass a sanity test. Then again, in my condition it’s an open question whether I’d pass a sanity test either ;) especially given that I’m not a climate scientist or any kind of scientist, so what exactly am I doing this investigation for?
I’m still guessing that supercooled H2O in polar clouds is behind the unmodeled portion of abrupt warming in 2023, a trend that seems to have begun in the southern hemisphere where recent atmospheric modeling of Hunga Tonga predicted net cooling.
I’m attributing the possible error in current atmospheric modeling to the same underestimation of supercooled H2O in polar clouds that causes current CMIP6 models to underestimate polar amplification. Whether or not I have actually identified a source of unmodeled 2023 abrupt warming is anybody’s guess until someone more proficient and resourced than I am looks over my results.
I’m sending explanations of how I am using this information, and a summary of my findings, to the people that I requested time series updates from. I figure if anyone is competent to investigate my method, it’s the people who are generating my source data.
I have similarly contacted several climate scientists too, in case my findings turn out to have significance that is beyond my capacity to demonstrate scientifically, or to understand.
Thanks for your kind support of my project in these comments here on Real Climate. It was a real shot in the arm to find that some people gave me credit for my work, even if I don’t have the expertise to do it professionally or defend what I discovered.
Here’s my latest thread of plots and explanations. I’m still tracking what looks like a Hunga Tonga warming surge that is decaying in remarkably similar fashion to the apparent time constant that I detected from Pinatubo.
For those on X/Twitter:
https://x.com/cheryl_josie/status/1965740643789267105
For those on BlueSky:
https://bsky.app/profile/cheryljosie.bsky.social/post/3lyi5v5tqak27
“I’ve tried since October to surmise an alternate explanation for the unexplained portion of 2023 warming”. If it’s big, fast & warmer then it’s a change in ocean mixing. I assume you mean that you’ll eventually detail quantities of this, that and the other ocean mixing. If it’s big, fast & cooler then it’s ocean mixing, big long volcano or an asteroid hit Earth.
Hi Cheryl. On your question “… so what exactly am I doing this investigation for?”
I may be a non-scientist guy, but even as such, I want to say I think what you’re doing is very cool! Seeking understanding and putting in the effort is an admirable quality. I wish I had something concrete to contribute to your pursuit, but I don’t. All I can offer is my two thumbs up.
A fine new Just Have a Think:
Are FOSSIL FUELS really all that bad??
https://www.youtube.com/watch?v=1uXYq_a26_U
[20 useful references included in “References” under “More”. It’s not long, well worth the time spent.]
GISTEMP (& NOAA) has posted for August, GISTEMP with a global anomaly of +1.14ºC. This GISTEMP Aug anomaly is a bit of a jump on the July anomaly (+1.01ºC) and the first upward wobble/step in an otherwise cooling trend since March. (Jan to Jun anomalies run +1.37ºC, +1.25ºC, +1.36ºC, +1.23ºC, +1.07ºC, +1.05ºC.)
Curiously while NOAA and ERA5 SAT also show an upward wobble/step, they are smaller. +1.00°C to +1.07°C in NOAA & +0.45°C to +0.49°C in ERA5. The GISTEMP SH anomaly is mostly responsible for the size of the GISTEMP Jul-to-Aug jump, +0.82°C to +1.02°C.
It is the 3rd warmest August on record and Aug25 is not significantly above the pre-“bananas!” August trend (as per this NOAA plot
2024 … … +1.30ºC
2023 … … +1.19ºC
2025 … … +1.14ºC
2016 … … +1.02ºC
2019 … … +0.95ºC
2022 … … +0.95ºC
2025 … … +1.14ºC
After the first ten days of September, ClimatePulse is showing the daily ERA5 anomalies continuing in an upward wobble that started at the end of August. This wobble is putting the daily anomalies above the pre-“bananas!” projected 2010-22 trend line. (I’ve plotted this 2010-22 trend line on the graphic of ERA5 global temp 2022-to-date First Posted 17th March 2025 HERE. The August-so-far anomaly sits at +0.55ºC while the all-month ERA5 trend sits at +0.51ºC.
The actual ERA5 2010-22 trend value +0.30ºC/decade is surely a bit ‘fragile’ given the short period of the OLS. The equivalent NOAA & GISTEMP trends works out at +0.26ºC while HadCRUT5 is +0.23ºC. Mind, ERA5 is SAT not SAT/SST.
What I am not seeing yet in these 2025 anomalies (as autumn begins) is any significant rise in the NH anomaly. The upward wobble of the last couple of weeks is all SH.
This across Land and Ocean?
Pete Best,
All the above numbers are across land & ocean.
Hansen, et al., continue to lead on climate. More from them, less minimizing of their work from some others, please.
https://x.com/peakaustria/status/1966744672992121035
Killian. Sure, I’ll bite. The multi-decadal warming trend right now is substantially <+0.36 / decade, more like +0.29 / decade. Get back to me in 2032 CE please (same offer I made to a "Dan Miller" Social Type, pleasant bloke circa Oct 2024, when he stated that my opinion that GMST had not reached 1.5 degrees above 1850-1900 was obviously incorrect). Pick those delicious cherries mate. After all, what's sauce for the Fossils is sauce for the Other Business Models and Whatnot. And that's exactly how the physical sciences should progress. I suppose.
Barry E Finch: – “The multi-decadal warming trend right now is substantially <+0.36 / decade, more like +0.29 / decade.”
Evidence/data? Grant Foster and Stefan Rahmstorf have produced a pre-print paper titled Global Warming has Accelerated Significantly, currently in peer-review, available at Research Square. It included (bold text my emphasis):
https://www.researchsquare.com/article/rs-6079807/v1
Barry E Finch: – “Get back to me in 2032 CE please (same offer I made to a “Dan Miller” Social Type, pleasant bloke circa Oct 2024, when he stated that my opinion that GMST had not reached 1.5 degrees above 1850-1900 was obviously incorrect).”
Barry, please specify what your ground rules are:
* GMST Dataset? NASA, NOAA, HadCRU, Berkeley Earth, Copernicus ERA5, or other?
* GMST Baseline? 1850-1900, or other?
* Mean Time Period? Daily? Weekly? Monthly? 365-day running mean? 2-year running mean? 5-year running mean? 10-year running mean? 20-year running mean? 30-year running mean? or other mean time variant?
To 7 June 2025, using Copernicus ERA5 dataset, with 1850-1900 reference baseline:
* 791 days over +1.50 °C
* 139 days over +1.75 °C
* 006 days over +2.00 °C
* 26 months over +1.50 °C
* 04 months over +1.75 °C
* 12-month running mean at +1.57 °C
* 30-year LOESS smooth running mean at +1.42 °C
https://parisagreementtemperatureindex.com/climate-milestone-counts/
These are running means. I’d suggest that on a general warming trend, the Earth System has likely already crossed the +1.5 °C GMST anomaly 30-year centred-mean threshold, relative to the 1850-1900 baseline, but we won’t know for sure for another 15 years until the full data emerges.
Geoff Miell, the ocean (it’s a big wet thing).
Barry E Finch: – “…the ocean (it’s a big wet thing).”
Global Mean Surface Temperature (GMST) is the weighted average of near-surface air temperature over both land and sea surface temperature over ice-free oceans, providing a single metric to track the overall warming or cooling of the Earth’s climate system.
As a general rule of thumb, a global average warming of +4 °C (for both land & ocean) is consistent with +6 °C over land only, and +8 °C in the average warming over mid-latitude land. That risks +10 °C in the mid-latitude summer average, or perhaps +12 °C in extremes. Western Sydney has already reached 48 °C. If you add 12 °C to the 48 °C you get summer extremes of perhaps 60 °C.
See page 10: https://www.breakthroughonline.org.au/dor
It’s clear to me you are engaging in distractions to avoid answering my question:
Reiterating again Barry, please specify what your ground rules are:
* GMST Dataset? NASA, NOAA, HadCRU, Berkeley Earth, Copernicus ERA5, or other?
* GMST Baseline? 1850-1900, or other?
* Mean Time Period? Daily? Weekly? Monthly? 365-day running mean? 2-year running mean? 5-year running mean? 10-year running mean? 20-year running mean? 30-year running mean? or other mean time variant?
Otherwise, that provides you, Barry, with the opportunity to keep changing the goal posts. I suspect that’s your intent.
The pre-print is talking about the rate of AGW, i.e. the global temperature trend with the impact of volcanoes, total solar irradiance, and ENSO subtracted out. That is not the same thing as the observed global warming trend. Check the pre-print:
“In conclusion, removing the best estimate of the influence of three natural variability factors on global temperature reduces the noise level of the data sufficiently to reveal a large and significant acceleration of global warming“
There’s a PubPeer thread covering this topic:
https://pubpeer.com/publications/973ABFB81F504E8CB1B50E941CF3F7#1
Shush till you have something to actually say. I have made the point too often using a 30-year time frame to judge changes coming far faster than when that time frame was established is unintelligent. When your scale no longer applies, you change the scale.
But, please, continue to act unintelligently while I continue to be ahead of the curve.
Killian: “ Shush till you have something to actually say.”
Teacher, teach yourself – the 30-yr time averages are not chosen arbitrarily, or as a conspiracy by scientists to hide the AGW signal the laymen with strong opinions like you, but to reduce the shorter-term noise by averaging out the shorter-term OSCILLATIONS around the mean (including, but no limited to, biennial, 2-7 yrs ENSO cycles, decadal (e.g. PDO) and others).
So unless you have a proof that ALL those oscillations have recently became … 3 TIMES shorter – shush yourself, shusher.
Killian: But, please, continue to act unintelligently while I continue to be ahead of the curve.
Pride goeth before destruction, and an haughty spirit before a fall…
(cont. from
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
&
https://www.realclimate.org/index.php/archives/2024/04/unforced-variations-apr-2024/comment-page-2/#comment-821231 ,
https://www.realclimate.org/index.php/archives/2024/04/unforced-variations-apr-2024/comment-page-2/#comment-821248 ,
https://www.realclimate.org/index.php/archives/2023/07/unforced-variations-july-2023/#comment-812960 ,
https://www.realclimate.org/index.php/archives/2023/07/unforced-variations-july-2023/#comment-812965 ,
https://www.realclimate.org/index.php/archives/2023/07/unforced-variations-july-2023/#comment-813067 ,
https://www.realclimate.org/index.php/archives/2023/07/unforced-variations-july-2023/#comment-813068
https://www.realclimate.org/index.php/archives/2024/06/unforced-variations-june-2024/#comment-822842
https://www.realclimate.org/index.php/archives/2025/08/unforced-variations-aug-2025/comment-page-2/#comment-838670 )
https://en.wikipedia.org/wiki/Atmospheric_circulation#Ferrel_cell :
WTF?
This seems to go against everything I’ve read about it.
My understanding (from reading and reasoning) is: (and there are some things I don’t understand, but FWIW)
eddy (baroclinic waves and what spins off of them) thermal advection creates anomalies and advects those anomalies (v’T’) so warm air advection (WAA) shifts poleward as baroclinic waves grow, and associated with that, surface Lows (L’s) build poleward (L’s are ≈ warm core at sfc (initially) and tilt westward w/ height into the cold air; etc. for Highs (H’s); (I expect cold air advection (CAA) would likewise shift equatorward and bring sfc H’s with.) Poleward flow at the surface from H’s to L’s converts APE to KE there, the Coriolis force turns this to westerlies, resupplying momentum and energy lost to surface friction/viscosity. Rising motion follows, with the upper branch of the Ferrel cell converting KE to APE because the eddy heat flux reduces but doesn’t eliminate the equatorward pressure gradient there …
(and eddy momentum fluxes add KE and westerly momentum there, which I imagine may also add to the surface p gradient …? And then there’s the stuff about eddy PV flux and the cell seen in (y,θ), but also jet sharpening by enhanced eddy PV mixing closer to where the critical level is at the height where eddy momentum fluxes are concentrated – creating ‘PV staircase’ – but then how does the eddy PV flux across the baroclinic zone continue…? )
… and then this is completed by the sinking in the subtropics; the Ferrel cell adiabatically undoes some of the eddy T changes but it can’t balance those on its own as this would tend to undo the conversion from zonal mean APE to eddy APE (except maybe for the barotropic PE of the surface p changes?) … so the remaining eddy heat flux is balanced by diabatic heating/cooling which recharges the APE…
So the Polar and Hadley cells may help drive the baroclinic eddy activity via there heat fluxes warming the subtropics and cooling the subpolar regions, and additionally help drive the Ferrel cell by supplying a source of upper-level westerly momentum for the eddies to grab, but the eddies also help drive the Polar and Hadley cells by grabbing said westerly momentum and maybe also by warming and cooling their own edges.
So … I guess I’ll have to check out that citation [8] sometime…
Patrick, I’d wondered since I started in 2013 and first saw the stylized pictorial of Cells why the Ferrel Cell was shown with the air at the top of the troposphere at the 60N Polar Cell boundary flowing up hill, defying gravity, to the 30N Hadley Cell boundary (too cheap to buy text books). Eventually I came across a UTube video by some University Professor with that pictorial and in non-answer to me he gave a worthless “those are just overall averages”. Few years later I came across the actual scientist statement “…the thermally-driven Hadley and Polar Cells and the weak mechanically-driven Ferrel Cell….” and that answered that. Seems to me remaining question for me is the proportion of driving force that’s from presumably-weakening Polar Cell and from presumably-not-weakening-much Hadley Cell.
The Ferrel, Polar, and Hadley Cells are all zonal averages (averaged over all longitudes) of the N-S and up-down velocities* –
– *well, actually, they may be shown as contours (streamlines) of a mass flow streamfunction; the small lengths at higher latitudes means less mass is circulated for a given velocity so the polar cell will be weaker than otherwise for that reason when quantified as such.
– And they may be time averages, though I’m not sure how much of a difference that makes. In the absence of geography to force (or feedback on) zonal assymetries ie. continents, mountains, deserts, topography of the seafloor, etc., the time average at any one longitude would tend to look like the zonal-time average.
Anyway, my understanding is that, to a degree greater than the Hadley cell in the tropics, snapshots of the flow at any one place and time in the midlatitudes will frequently be quite different then the zonal(-time) mean. (Not sure about Polar regions.)
(Even with the Hadley cell, I once read something which gave me the impression that there may be a (tendency for) horizontally-~homogeneous sinking motion outside of updrafts in cumulus convection(*?*), aside from the temporary oscillations of gravity waves (the cumulus updrafts are like dropping stones in a pond; the gravity waves (like ripples on the pond) carry away information on changes in the mass distribution, so the level of the pond ultimately goes up by the same amount at all locations; the Coriolis force limits the horizontal extent of the adjustment, but this is weak in the deep tropics.) So the Hadley cell would be an average of that motion (*?*)… and tropical cyclones, the Walker Circulation, monsoons, land/sea breezes, etc.)
But anyway, I’m quite confident that eddies drive the Ferrel cell, and those eddies specifically are not the Hadley and Polar cells (they don’t force the Ferrel cell other than maybe helping via their heat transport and momentum supply – the later *not* in the sense of dragging as if the midlatitudes were a gear between two other gears – that’s just not what’s happenning) – in fact I don’t think any of these cells would be considered eddies at all. In some contexts an eddy may be defined as a deviation (with quantities a’) from some average (a₀ , with total a = a₀ + a’; a could be T or u (zonal velocity component) or v (northward velocity component), etc. wave fields are eddy fields), and the cells are an average.
I’m not sure how much persistent stationary (ie. climatological) waves/eddies could drive a Ferrel cell, but the transient eddies (ie. weather) can.
“The General Circulation of the Atmosphere” Tapio Schneider
https://courses.seas.harvard.edu/climate/eli/Courses/EPS281r/Sources/Hadley-cell/more/Schneider-2006.pdf (open access link)
When the model (for a zonally-symmetric idealized planet) is run with no eddies (no deviations from zonal symmetry) allowed, there are only the Hadley cells (see fig.3 upper row, vs bottom row; p.11/34). Their poleward extent is limited by the Coriolis effect. This all makes sense. (Offhand I think there is some weak extension that reaches into the polar regions, but there is no separate polar cell, and I wonder if the polar cells that exist in reality are themselves substantially much stronger because of the eddies that drive the Ferrel cell(?))
“ but the eddies also help drive the Polar and Hadley cells by grabbing said westerly momentum and maybe also by warming and cooling their own edges.” – or perhaps unleash/release them (conversion of their APE to KE, which is held back by the Coriolis effect).
[8]: https://en.wikipedia.org/wiki/Atmospheric_circulation#cite_note-The_Climate_System:_General_Circulation_and_Climate_Zones-8
:
https://web.archive.org/web/20040822022845/http://eesc.columbia.edu/courses/ees/climate/lectures/gen_circ/index.html : under section “VI. Baroclinic instability.” (some formatting lost)
This is more in line with my understanding and doesn’t support the Wikipedia section which cites it. I only skimmed this source but why would they say this and then say the other thing elsewhere?
PS Thought experiment (mental model) (this is reasoning from the physics AIUI)
Imagine a θ sfc in y,z (or y,p), sloping upward poleward (the sfc projects initially as a sloping line in y,p (p positive downward)). The v’ of the baroclinic eddies advect it poleward and equatorward; the crests and troughs of the wave project as separating lines. The flow slopes in the same direction as the slopes of the lines but more gently, so the lines still move apart (eddy APE increasing, supporting the eddy u’,v’ pattern in near-geostrophic or near gradient wind balance), but there is upward and downward motion (APE → KE).
To some extent the vertical motions in the warm and cold phases balance each other (eg. on the critical surface (steering level), Q vectors point from cold anomaly to warm anomaly at Low, High centers; given how isotherms are being rotated around those points), but presumably there should be compensating motion elsewhere as well – ie. in an y,p cross section through each part of the wave, there should tend to be a pair of cells, one thermally direct on the side the T anomaly is advecting toward (because the thermal gradient is increasing; isotherms pushing together), and one thermally indirect opposite that (because the thermal gradient is decreasing (isotherms pulling apart). …
https://en.wikipedia.org/wiki/Q-Vectors (to ease interpretation, try using a local x,y coordinate system where x is locally-aligned with isotherms with T increasing equatorward.)
… When warm/cold air intrudes into cooler/warmer air, as the rising/sinking motion (in p) of the first adiabatically reduces the T perturbation, the compensatory sinking/rising motion of the surrounding air will adiabatically spread the T perturbation horizontally. Diabatic cooling/heating (eg. net radiant cooling anomaly) then raises/lowers the θ sfc through the air. The later projects onto the zonal average in y,θ (isentropic coordinates) as the vertical branches of a cell (or an extension of the Hadley cell) that overturns counter to the Ferrel cell, and this (by my reasoning) includes air that did not cross the baroclinic zone. The horizontal motions of warm/cold air at the same p will project in y,θ as the horizontal branches of said cell.
…
I don’t know if this has been mentioned but I just learned this.
Eunice Newton Foote (born Eunice Newton; July 17, 1819 – September 30, 1888) was an American scientist, inventor, and women’s rights campaigner. She was the first scientist to identify the insulating effect of certain gases, and that therefore rising carbon dioxide (CO2) levels could increase atmospheric temperature and affect climate, a phenomenon now referred to as the greenhouse effect. Born in Connecticut, Foote was raised in New York at the center of social and political movements of her day, such as the abolition of slavery, anti-alcohol activism, and women’s rights. She attended the Troy Female Seminary and the Rensselaer School from age 17 to age 19, gaining a broad education in scientific theory and practice.
https://en.wikipedia.org/wiki/Eunice_Newton_Foote
Chris Wright & his climate group must immediately fly down under and set the Aussies straight! A pacific hands across the sea and all that:
.
“Heat deaths to soar from ‘cascading’ climate risks, landmark federal report warns”
https://www.smh.com.au/politics/federal/heat-deaths-to-soar-from-cascading-climate-risks-landmark-federal-report-warns-20250915-p5mv1v.html
.
Also, I have a “three monkeys” wall ornament I’ll loan the American administration’s for this presentation (for a, I think, quite reasonable rate!).
A bit of weather data from the experts, who keep adding to our knowledge base on weather and climate:
https://yaleclimateconnections.org/2025/09/august-2025-earths-3rd-hottest-august-on-record/
[in season, they mostly cover tropical storms, but their data collection is superb]
—
Adding this here, re an earlier comment:
BJ Chippindale, I failed to mention most recent posts at RabettRun are from “Eli”‘s more active colleague Brian]
“We have to start asking: What do we value economically? What can we retain and defend, and what things are we going to have to abandon? Because there are things we are going to have to abandon.” – Ian Dunlop, “former Shell executive and Australian Institute of Company Directors chair, is now a senior member of the Australian Security Leaders Climate Group”
“[And] if projects can’t be insured, they essentially can’t be built, because no-one can take that sort of risk on. … People don’t always appreciate how crucial insurance is to actually getting investment happening.” – Dr. Emma Aisbett, economist at the Australian National University
.
https://www.abc.net.au/news/2025-09-16/climate-risk-assessment-million-homes-insurance-gdp-costs/105774418
.
They are talking about Australia. But, (stating the obvious) the same concerns applies to every developed modern economy in the world. I’ll bet a dollar or two that it’s the Insurers that will be increasingly more vocal about the financial implications to individuals and nations of what’s coming.
Too many in the U.S. ignorantly wave away climate scientists’ work produced over the last 30+ years. Will they listen to their insurance agent?
MA Rodger says
(2025) It is the 3rd warmest August on record and Aug25 is not significantly above the pre-“bananas!” August trend (as per this NOAA plot
the post-2016 super El Nino years 2017 To 2022 pre-“bananas!” AUG Avg Anomaly = +0.89 C
vs 2025 +1.14ºC = + 0.25 C higher ~28% above avg.
No pre-“bananas!” 2017 To 2022 years were above the 2016 El Nino Aug +1.0C
but the non-El Nino AUG 2025 is.
AUG 2025 being the third highest Aug anomaly, the 3rd yr in a row, is significant in itself being a neutral ENSO year.
And 2025 YTD Avg. August Anomaly is +1.17 C the 2nd highest on record
2024 + 1.28 C
2025 + 1.17 C
2016 + 1.09 C
2023 + 1.08 C
2020 + 1.05 C
https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/global/time-series/globe/land_ocean/tavg/ytd/8/2000-2025?trend=true&trend_base=10&begtrendyear=1995&endtrendyear=2025&filter=true&filterType=binomial
Apologies to TK: I didn’t realize I had posted only one of the water vapor web pages. Here are both:
https://bartonlevenson.com/Irrigation.html (irrigation)
https://bartonlevenson.com/Pangburn.html (precipitable water)
Tomáš Kalisz says 16 Sep 2025 at 2:10 PM
I asked if Hansen could be right (that the PRESENT climate sensitivity is higher than estimated previously)
and If you know the answers to my questions, please let me know.
OK, I do not know Tomas.
And Hansen on ECS could be right, half right or he may be wrong . Who knows at this point? The majority and the IPCC system say he is wrong. Are they right? Time will tell.
in Re to Mo Yunus, 16 Sep 2025 at 9:42 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839395
Dear Mo,
The point to that I focus is the question if a study, modelling and comparing climate sensitivities for two extreme states of Earth land hydrological regimes (a “swamp land” and a “desert land”, analogously as in Lague et al
https://iopscience.iop.org/article/10.1088/1748-9326/acdbe1 ),
could be technically feasible and could provide the respective hint how much this topic may or may not be relevant. I also believe that time will tell, however, I hope that this study could speed up this process a little bit.
Greetings
Tomáš
Piotr says
15 Sep 2025 at 11:39 PM
“Mo Yunus”: “ That reframes the picture: CO₂ initiates the imbalance, but the expression of that imbalance is strongly mediated by clouds and shortwave absorption.
MoY: In short this paper directly reinforces Hansen’s warning that cloud actions (feedback + forcing) are central, models may be missing them.
Addendum> Raghuraman et al. reinforce why Hansen’s hypothesis deserves attention, but they also underscore that the observational record is complex and currently doesn’t give a simple, high-confidence measurement of net cloud feedback that would definitively raise ECS.
Both focus on cloud–aerosol forcing and feedback as central to Earth’s energy imbalance and ECS uncertainty. But the direction of the effect is debated — Hansen’s view tilts toward stronger positive feedbacks and higher sensitivity, while this observational study finds substantial cancellation and warns against over-interpreting CRE trends.
I am not interested in semantic zero sum games or arguing about arguing. Piotr if you think you can provide a better summary of the findings and possible implications for future research / certainty of this peer reviewed paper then go ahead.
5. Discussion
Recent studies have decomposed CRE changes into cloud-controlling factors (Andersen et al. 2022; Klein et al. 2017; Scott et al. 2020). Our study suggests that such an analysis should include forcing in the cloud controlling factors or remove forcing from their SST-mediated controlling factors. Our study showed that using CRE as a proxy for cloud feedback is a poor approximation since CRE is a combination of various factors (Fig. 6, Table 3, appendix).
https://journals.ametsoc.org/view/journals/clim/36/12/JCLI-D-22-0555.1.xml#d9733772e1784
6. Summary and conclusions
We showed that the observed global-mean trends in LWCRE and SWCRE are extremely unlikely to be due to unforced variability alone (Fig. 1). SWCRE ERF was found to have a large enough signal that it could account for slightly over half of the observed positive SWCRE trend via cloud adjustments (greenhouse gas increases, aerosol decreases, and natural forcing agents) (Figs. 2 and 3). The role of ERF was highlighted regionally, and it was shown that the PDO has little impact on the flux changes in the northeast Pacific (Fig. 3). We found that cloud masking, arising from ERF and surface warming, yielded a strongly negative trend in LWCRE since greenhouse gases reduce OLR in clear-sky conditions more than in all-sky conditions and could account for slightly over half of the observed negative LWCRE trend (Figs. 4 and 5 and Table 2).
https://journals.ametsoc.org/view/journals/clim/36/12/JCLI-D-22-0555.1.xml#d9733772e1929
Mo 16 Sep: “I am not interested in semantic zero sum games or arguing about arguing.
X: “I believe that the Earth is flat”
Y: “No, there many proofs that the Earth is NOT flat”
X: “I am not interested in semantic zero sum games or arguing about arguing.”
Mo: Piotr if you think you can provide a better summary of the findings and possible implications for future research / certainty of this peer reviewed paper then go ahead.
Huh? It was you who made the bold claim ( “[this paper] reframes the picture”) – so the onus of proof is on you, not on me. And why your Sep. 13 post offered no such proof, I have already demonstrated on Sep. 15:
===================
– Mo: 13 Sep “ [Raghuraman et al. ] reframes the picture: CO₂ initiates the imbalance, but the expression of that imbalance is strongly mediated by clouds and shortwave absorption.
– Piotr: 15 Sep.: “Quite the opposite – the water cycle, including clouds, is almost exclusively a PASSIVE positive feedback and as such – it “mediates” nothing – it merely follows and passively amplifies the effects of GHGs. As such, contrary to your characterization, which attempted to REDUCE the importance of GHGs to being a mere “initiator”, while INFLATING the role of the water cycle from a passive FEEDBACK to an active and strong ACTOR (“strongly mediating”) – the actual implications are opposite to yours – your “enlightening” paper reinforces the importance of GHGs to the climate, by making climate MORE sensitive to even small changes in GHGs:
– if we increase the GHGs, the RESULTING cloud decrease will make the warming bigger than by the increase in GHGs alone ( as shown by your “reframing” Raghuraman et al.)
– if we decreased the GHGs, the RESULTING cloud increase would make the cooling bigger
than by the decrease in GHGs alone,”
– Mo 16 Sep: “I am not interested in semantic zero sum games or arguing about arguing.
When the going gets tough, the tough get going, eh? ;-)
Don’t know if this was already pointed out, but I had missed it:
https://www.euronews.com/green/2025/09/17/silent-killer-climate-change-led-to-16500-more-heat-deaths-in-europe-this-summer-study-say
The researchers estimated ~24k heat deaths in a set of over 850 European cities this summer, attributing nearly 70%–16.5k–to anthropogenic climate change. Their data set covers about 30% of the continent’s population, so extrapolating would suggest that climate change killed something fairly close on the order of 50k people in Europe this summer.
I wasn’t able to track down the original paper, though Friederike Otto and Garyfallos Konstantinoudis were mentioned as authors.
I saw that report on the NYTimes this morning (https://www.nytimes.com/2025/09/17/climate/europe-heat-deaths-climate-change.html) and linked to it on aTTP! The NYT science reporter, Raymond Zhong, said it hasn’t been peer-reviewed yet, and named two of the authors, Malcolm Mistry, who “contributed to” the analysis, and Garyfallos Konstantinoudis, who “worked on” it.
Corals Won’t Survive a Warmer Planet, a New Study Finds.
Apparently, a quarter of all ocean life depends on coral reefs and over a billion people worldwide benefit from them, according to NOAA.
S. Emmerson: “Corals Won’t Survive a Warmer Planet, a New Study Finds.”
the paper to which the above text links to – “Reduced Atlantic reef growth past 2 °C warming amplifies sea-level impacts” does not seem to have this conclusion. In fact, the focus of the paper seems to be … human-oriented – the limited capacity of the coral reef to …. protect the shoreline against SLR: e.g.:
Section : Implications
“Our findings project a bleak future for the capacity of TWA coral reefs to limit SLR effects under future climate scenarios.”
The inability of coral reefs vertical growth to keep up with SLR over next decades -is not yet a proof of Coral reefs, and diversity they support, “not surviving”.
For survival, or not, much more relevant are:
-the extent of the coral bleaching, affected both by the intensity of the heat waves,
– the ability (or not) of corals to recover from bleaching – which in turn depends on:
the frequency of the heat waves (how much time to recover before the next one hits)
– and on other stressors impeding the ability to recover between the consecutive heat waves, such as:
– ocean acidification,
– physical destruction by storms, fishing, shipping and tourism,
– increase in fertilizer/human waste runoff (extra nutrients help the competitors of corals),
– increase in suspended matter blocking the light for corals (river runoff, dumping of dredged material)
-toxic pollution (cyanide fishing, oil-spills).
These are the processes we need to consider (model) when discussing the survival, or not, of coral reefs.
BTW – there some interesting work on mechanism of bleaching – it may be that when zooxanthellae (the mutualistic algae living inside corals) are stressed (e.g. by heat) they produce irritating chemicals that make the corals expel them. So the idea is to raise (genetically-modify?) the strains of zooxanthellae that would be less sensitive to the stress, thus less likely to be expelled …
Thanks, Piotr.
The red text was taken from a headline. I feared it might be an exaggeration but didn’t have time to read the paper myself as I had to care for my wife. I was hoping someone would and, subsequently, comment.
After reading the paper, I agree that the main thrust is the ability of corals to keep up with SLR.
The paper does, however, have SST as a major influence on this ability (see “Future projections of RAPmax under SLR” and “Extended Data Fig. 5”). They did put this in the abstract:
They also noted a positive feedback mechanism: not keeping up with SLR makes it more difficult to keep up with SLR.
The BEST August Temperature Update has an analysis of the North Pacific August SST record which some may find interesting.
They point out that the Aug 2025 anomaly sits in the <1% likelihood zone of SSP2-4.5 modelling and a smoothed record of this data suggests an Aug 2025 N Pacific SST anomaly about +1.0ºC above the averaged modelling result.
The coverage then goes on to propose that “a likely explanation for faster than anticipated warming in the Northern Pacific is potential role of recent reductions in sulfur aerosol pollution.” They continue, pointing out that an aerosol effect “does not seem large enough to explain the entire divergence between Northern Pacific temperatures and climate models, but may explain a significant part of it.” (There are other unmentioned potential reasons for this elevated N Pacific SST.)
They do not mention the size of any N Pacific contribution to the unexpectedly high global temperatures 2023-to-date but do provide a link to their 2024 Global Temperature Report which did show the existence of a “diversity of estimates of the net effect” of ‘marine pollution’ on the 2023-24 global temperature, indeed larger estimates than that given in their 2023 report, larger as per their 2024 graphic HERE. (I can’t see a link to any source for their “diversity of estimates.”)
Sun Day : September 21, 2025. Rise up for a sun powered planet!
https://www.youtube.com/watch?v=FYSUNNGvv48
Excellent coverage about the business as well as humanistic benefits of clean renewable energy from the very fine Dave Borlace.
Additionally, courtesy of YCC:
Bill McKibben says cheap solar could topple Big Oil’s power
The veteran activist says that solar has finally scaled to the size of the climate crisis – and he’s organizing a nationwide “Sun Day” this weekend to promote clean energy.
by Michael Svoboda September 18 2025
https://yaleclimateconnections.org/2025/09/bill-mckibben-says-cheap-solar-could-topple-big-oils-power/
To be honest, I couldn’t find any Sun Day protests which were not religious. I had hoped to join a Make Billionaires Pay event, but am beginning to feel that actions outside marches and mass gatherings are needed more. If one can get access to legislators, that’s better, or join a gardening or helping event.
But I really came here to share an addition to the Just Have a Think presentation, which provides facts about the Lazard LCOE presentation:
https://www.lazard.com/media/uounhon4/lazards-lcoeplus-june-2025.pdf
Lazard, by the way, is not remotely ‘left’ or ‘woke’. Fact is, clean energy is growing by leaps and bounds and is profitable as well.
Repeat link to original, which imho is about facts more than about joining the movement: https://www.youtube.com/watch?v=FYSUNNGvv48
in Re to Barton Paul Levenson, 16 Sep 2025 at 8:06 AM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-839369
Hallo Barton,
Thank you very much for the reference to your estimations of the precipitable water in Earth atmosphere.
I suppose that it is in reply to my post of 3 Sep 2025 at 3:39 PM,
https://www.realclimate.org/index.php/archives/2025/09/unforced-variations-sep-2025/#comment-838819 ,
and highly appreciate your effort.
I do not think, however, that the cited data enable any conclusion about the relationship between water availability for evaporation from the land and climate sensitivity. I am, therefore still afraid that this relationship may still represent a blind spot of the state-of-art climate science.
Greetings
Tomáš
On 15 Sep 2025, the Australian Government published Australia’s first National Climate Risk Assessment.
https://www.dcceew.gov.au/climate-change/policy/adaptation/ncra
There was a public hearing on 16 Sep 2025, conducted by the Australian Senate Environment and Communications References Committee concerning an inquiry into the Climate Risk Assessment.
https://www.aph.gov.au/Parliamentary_Business/Committees/Senate/Environment_and_Communications/CRA48P/Public_Hearings
Mr. Greg Mullins AO AFSM, Climate Councillor and founder of Emergency Leaders for Climate Action (ELCA), who was a witness that appeared at the referred Senate public hearing, in response to a question about some politicians who are advocating abandoning greenhouse gas emission reduction commitments, said:
“They’re ignoring the facts; they’re abandoning the community; and they don’t care – that’s the message. It’s all about, it all seems to be about politics, and ah… That’s, that’s really sad. Um, you’re probably aware that prior to the ‘black summer’ bushfires, ah, 23 former fire and emergency chiefs from every state and territory, every fire service in Australia, we tried to meet with the Prime Minister, Scott Morrison; we warned that a catastrophic bushfire season was coming, we were ridiculed, um, ignored, until it was way too late. And that, it seems to be going back to that. And I, I don’t understand it, um; we’ve all got kids, you know, a lot of us have grandkids. Um, I don’t understand the humanity behind it. So, so I’m appalled, I’m just appalled. And they work for us; we pay them. So, I, I just don’t get it!”
https://youtu.be/kshsde6g59Y?t=24549
And economist Dr Richard Denniss said at the Senate hearing on Tuesday:
“Let me give you an example of how much worse things are, ah, than you might likely expect. A lot of people talk about insurance becoming unaffordable. Just to be crystal clear, every mortgage contract in Australia obliges the holder of the mortgage to have insurance. Every mortgage contract. The reason we think bank lending is safe, is that not only they’re lending against real estate, they’re lending against insured real estate. So, the entire risk profile of the entire financial system is based on the idea that house prices don’t go down, and even if houses burst into flames, it’s actually the insurance company’s risk, not the bank’s risk. So, to be crystal clear, if a house is uninsurable, it is unmortgageable. If a house is uninsurable, it is unmortgageable. The potential catastrophic impacts of whole suburbs and regions not being able to insure their houses is not included in this report, rightly, because the tools for doing so, don’t exist. But again, to be crystal clear, the bank expects that if you’ve got a mortgage your house is fully insured. If your house is not fully insured, you are in breach of your mortgage contract. Right now in Australia today, we know there are people who are uninsured. Right now, in Australia today, we know there are people who are under-insured. The RBA isn’t looking, APRA isn’t looking, ASIC aren’t looking. Everybody knows that not only is there uninsurance and under-insurance today, what this report has just told us is that in the coming decades there will be far more of this. This is a crucial part of the problem that our regulators are ignoring, and that this report can’t have provided the answers to. Just quickly, when this damage comes, someone will have to pay. You can only insure against unlikely events. Insurance companies do not insure against likely events. No 20-year-old in Australia can rent a Ferrari and insure it. Okay, you can’t insure against that risk. What this report says is that flooding will be so common in large parts of Australia, you will not be able to insure. So, just to be clear, individuals will not insure their way out of this crisis. You cannot insure against likely events. So, what is going to happen is we are either going to tell people: ‘You are on your own, you are stranded, your house is worthless, we are sad for you,’ or we are going to say: ‘Oh, I’m so sad that we are actually going to give you large amounts of public money.’ But, to do what? To rebuild in the place that keeps flooding? To move? To where? These are not hypothetical. And to give everyone a sense of timing, we’re telling 20-year-olds today to worry about a mortgage, that they won’t pay off before 2050. We’re telling 20-year-olds to worry about superannuation, that they won’t get their hands on till they get to 2065. And this report is saying there are catastrophic risks coming right now, way before you need your super, way before you pay off your 25- to 30-year loan. So, the fossil fuel industry seems to me to be the obvious person to pay for this, because in Australia today we are giving half of our gas away for free…”
https://youtu.be/kshsde6g59Y?t=12398
Yesterday (Sep 18), Michael McLaren had on-air at Radio 2GB his guest, Australian Opposition Leader Sussan Ley, who said:
“Good afternoon, Michael, great to be on the program, and, you’re right; it’s economy wide, and it’s economy wrecking, which is why the Coalition is dead against these 2035 emissions reduction targets. Targets, they’re a fantasy, they rest on flawed assumptions, and they actually can’t be believed.”
https://www.2gb.com/economy-wrecking-sussan-ley-calls-out-albos-emissions-targets/
If the current rate of warming (i.e. ~0.4 °C/decade) continues, then a global average surface temperature that is +3 °C (5.4 °F) above pre-industrial levels is likely to be reached by between years 2054 and 2065.
https://youtu.be/LXx65CVEQAc?t=3756
A 3 °C warmer world would be catastrophic for human civilisation, leading to mass displacement of billions of people, a collapse of ice sheets, widespread biodiversity loss, frequent extreme weather events, disrupted food systems, and severe global economic devastation, potentially causing irreversible societal collapse. Climate scientists like Hans Schellnhuber believe that while some humans would likely survive, much of what we’ve built over the past 2,000 years would be destroyed, making current organized human civilization incompatible with such high temperatures.
Global warming is disrupting ecosystems. It is disrupting human health and livelihoods, food security and our water supply. It is disrupting economic growth.
https://globaia.org/habitability
A vote for politicians advocating for abandoning timely and effective greenhouse gas emission reductions is a vote for civilisation collapse, and a vote for the suffering of billions of people’s lives and livelihoods in the coming years/decades!
Fundamentally it is about Climate Change Risks and Adaption.
National Climate Risk Assessment
This is the first national assessment of climate risks for Australia. The National Assessment identifies key risks and impacts to systems. It provides national climate risk information to help guide future adaptation across Australia.
by the Australian Climate Service https://www.acs.gov.au/
What is the point of the National Climate Risk Assessment? The assessment’s aim is to understand those risks, when they may occur, and identify vulnerabilities that can hopefully be addressed ahead of time. The report outlines the cascading, compounding and concurrent impacts of climate change on every community in the country.
Alongside the risk assessment, the federal government has released a National Adaptation Plan, and in the coming days it will release its 2035 emissions reduction targets.
“We don’t pretend it is easy. That’s why the National Adaptation Plan is a framework for all governments. Every government has something at stake,” Bowen said. “We will have to work together on this task.”
https://www.abc.net.au/news/2025-09-15/national-climate-risk-assessment-and-why-it-matters-explained/105773936
The National Adaptation Plan
Climate change is affecting all aspects of our society – including the natural environment, our health, infrastructure and the economy. Australia needs to better prepare for and manage increasing risks resulting from climate change.
The National Adaptation Plan helps drive this change, responding to the findings of the National Climate Risk Assessment. It provides guidance on how we adapt to climate risks and build our national resilience to climate impacts.
https://www.dcceew.gov.au/climate-change/policy/adaptation/nap
Followed by state based adaptation planning and action
eg The AdaptNSW website has been produced by the NSW Government to inform and empower communities, businesses, households and government to adapt to climate change.
https://www.climatechange.environment.nsw.gov.au/
eg This Interactive map displays the plausible future climate change in NSW and ACT relative to a baseline of average climate from 1990–2009. This baseline is a modelled output and not observational data.
All NSW 2020-39
Change in number of severe fire weather days (days where the Forest Fire Danger Index is over 50)
High Emissions scenario ssp3-7.0
Annual Change Annual +1.6 days
https://www.climatechange.environment.nsw.gov.au/projections-map
Mo Yunus: – “eg This Interactive map displays the plausible future climate change in NSW and ACT relative to a baseline of average climate from 1990–2009. This baseline is a modelled output and not observational data.”
Using the NSW Government’s Interactive climate change projections map, select for viewing options:
Please select a region: NSW
Climate projections for: Change in average max. temperature (°C)
I note at the top of the page there’s this statement (bold text my emphasis):
https://www.climatechange.environment.nsw.gov.au/projections-map
I think this risk outlook for maximum temperature is far too conservative.
At the current rate of warming (i.e. ~0.4 °C/decade), the +2.0 °C GMST anomaly limit (relative to the 1850-1900 baseline) is likely to be reached before 2040, the +2.5 °C GMST anomaly likely reached by around 2050, +3.0 °C GMST anomaly likely reached by around the 2060s, +3.5 °C GMST anomaly likely reached by around the 2070s.
See my Submission (#26) to the NSW Parliament Joint Select Committee on Net Zero Future re their inquiry into Emissions from the fossil fuel sector, published on Sep 10 at:
https://www.parliament.nsw.gov.au/committees/inquiries/Pages/inquiry-details.aspx?pk=3113
It’s the extremes that kill, not the averages.
Researchers from the ANU have projected that 50 °C days could occur in major Australian cities like Sydney and Melbourne between 2040 and 2050.
https://www.sbs.com.au/news/article/sydney-and-melbourne-should-prepare-for-50-degree-days-climate-researchers-warn/6z1kvr6me
Breakthrough National Centre for Climate Restoration published in Aug 2021 a report titled Degrees of Risk: Can the banking system survive climate warming of 3˚C? by David Spratt & Ian Dunlop. Page 10 included:
https://www.breakthroughonline.org.au/dor
People in major Australian cities need to work out whether their air-conditioning systems, or even themselves (if they won’t have access to reliable air-con), can handle 50+ °C temperatures within the next few decades.
IMO, AdaptNSW’s webpage titled Climate change impacts on sea level rise is also far too conservative.
https://www.climatechange.environment.nsw.gov.au/impacts-climate-change/weather-and-oceans/sea-level-rise
The rate of global mean SLR has been demonstrably accelerating:
• 1.3 mm/year average between 1901 to 1971 (averaged from multiple tidal gauge data, IPCC’s AR6 WG1);
• 1.9 mm/year average between 1971 to 2006 (averaged from multiple tidal gauge data, IPCC’s AR6 WG1);
• 2.11 mm/year decadal average from Jan 1993 to Dec 2002 (satellite altimetry, WMO’s SotGC2023);
• 3.33 mm/year decadal average from Jan 2003 to Dec 2012 (satellite altimetry, WMO’s SotGC2023);
• 4.77 mm/year decadal average from Jan 2014 to Dec 2023 (satellite altimetry, WMO’s SotGC2023);
• 5.9 mm/year annual average in year-2024 (satellite altimetry, NASA).
SLR is increasing in an exponential-like manner.
I would not be at all surprised to see the rate of global mean SLR accelerate further, from 5.9 mm/year in 2024 to 10 mm/year sometime in the 2030s, and double further to 20 mm/year before 2050. That likely equates to 40 to 50 cm of SLR relative to the year-2000 baseline by 2050, and multi-metre (i.e. ≥2 m) SLR before 2100. One metre of SLR would be catastrophic for many coastal cities.
Australia’s current legislated target to reduce emissions is 43% below 2005 levels by 2030 and to achieve net zero emissions by 2050. We are well underway to meeting the 2030 target by reducing emissions across all parts of the economy.
To help keep us on the path to net zero, the Australian Government has set a target to reduce emissions to 62–70% below 2005 levels by 2035.
Read the emissions reports to find out more about how we are tracking.
https://www.dcceew.gov.au/climate-change/emissions-reduction
Mo Yunus says we are well underway to meet Australia’s 2030 emissions target by reducing emissions across all parts of the economy. But when I look at his link, emissions reductions seems to have stalled over the last few years. Climateactiontracker.org says Australia isnt doing enough to reduce fossil fuel use and places unrealistic levels of reliance on land carbon sinks. So things might be underway but seem to have come to a grinding halt.
I did not say that, the govt website quoted said that.
https://www.dcceew.gov.au/climate-change/emissions-reduction
The info added to what Geoff Miell provided, FYI.
On 15 Sep 2025, the Australian Government published Australia’s first National Climate Risk Assessment.
https://www.dcceew.gov.au/climate-change/policy/adaptation/ncra
Mo Yunus: – “Australia’s current legislated target to reduce emissions is 43% below 2005 levels by 2030 and to achieve net zero emissions by 2050.”
For all intents and purposes the +1.5 °C GMST anomaly, relative to the 1850-1900 baseline, has already arrived. Humanity has failed to keep at or below the +1.5 °C GMST anomaly limit.
At the current rate of warming (i.e. ~0.4 °C/decade), the +2.0 °C GMST anomaly limit is likely to be reached before 2040, and the +2.5 °C GMST anomaly likely reached by around 2050.
See my Submission (#26) to the NSW Parliament Joint Select Committee on Net Zero Future re their inquiry into Emissions from the fossil fuel sector, published on Sep 10 at:
https://www.parliament.nsw.gov.au/committees/inquiries/Pages/inquiry-details.aspx?pk=3113
The Climate Action Tracker (CAT) suggests Australia’s NDCs are “INSUFFICIENT” for a less than +3 °C GMST anomaly world. CAT’s analysis for Australia’s 2035 NDC, which was submitted on 18 Sep 2025 to the UNFCCC, is to follow shortly.
https://climateactiontracker.org/countries/australia/
Net-zero by 2050 is FAR TOO LATE. The Laws of Physics are not negotiable!
OT: but this is the real problem, threaded through every issue and every effort to have a government for and by the people, and for and by reality and progress [so, because science and climate, not entirely OT]
https://www.theguardian.com/commentisfree/2025/sep/11/tories-rightwing-junktanks-no-10-government-civil-servants
A ground-breaking peer-reviewed paper has been published today by a collection of well-known scientists, academics and behavioural science practitioners led by New Zealand-based conservationist, Joseph Merz, of the Merz Institute.
The paper, published by Sage on 20 September 2023, details how our modern human behaviour is causing us to consume our natural resources at rates faster than they can be replenished, while also creating waste in excess of what the Earth can assimilate. The authors name and frame this existential threat the ‘Human Behavioural Crisis’ and propose that the crisis, which stems from maladaptive human behaviours, be recognised globally as a critical intervention point for tackling ecological overshoot (and its symptoms like climate change).
https://mahb.stanford.edu/library-item/press-release-ground-breaking-academic-paper-reveals-the-behavioural-crisis-driving-anthropogenic-ecological-overshoot/
https://www.theguardian.com/environment/2024/jan/13/human-behavioural-crisis-at-root-of-climate-breakdown-say-scientists
https://journals.sagepub.com/doi/10.1177/00368504231201372
https://www.researchgate.net/publication/374062006_World_scientists'_warning_The_behavioural_crisis_driving_ecological_overshoot_SCIENCE_PROGRESS (PDF)
Constantly lumping all criticism into the category of “denialism” is an unfair and immoral tactic. It closes off important conversations and pushes away people who might otherwise be allies. It replaces reasoned debate with a punitive, “us vs. them” mentality, and in doing so, becomes as toxic and unhelpful as the rhetoric it claims to oppose.
To me, this is a moral dilemma. A group defending a scientifically sound position can start to adopt the same rigid, unforgiving tactics as the very people they’re fighting against. A comparison to the Stanford prison experiment makes perfect sense here; an adversarial dynamic can corrupt even people with good intentions, leading to behavior that is dehumanizing and cruel.
The toxicity of the online discourse surrounding climate change is well known. When I see a website that consistently frames every challenging question or comment or reference as an intentional act of “denialism,” it to creates a permanent hostile environment. This shuts down genuine curiosity and makes it impossible to have a real discussion.
This “us vs. them” mentality has a number of negative effects on any online forum: It silences good-faith discussion. It erodes trust in the moderators and the site’s purpose. It leads to a decline in quality of content. The focus shifts from explaining complex topics to winning arguments. The discussion becomes less about sharing knowledge and more about scoring points. This can lead to a race to the bottom, where participants resort to insults, straw man arguments, and cherry-picking data, rather than engaging in thoughtful, evidence-based conversation. Providing exactly what those behind people like Trump want to happen.
Mo: “ Constantly lumping all criticism into the category of “denialism” is an unfair and immoral tactic.
Could you be specific – give examples of the people who are “unfairly and immorally” called denialists? Trump, Bannon, Project 2025, DOE, EPA, MAGA, Ken Towe, Keith Woollard, KIA, “anything but GHGs” deniers like JCM and T.Kalisz?
If somebody constantly questions the reality of climate change and/or tries to undermine the credibility of the climate science, and/or praises fossil fuels, and/or proposes diverting resources from GHGs reductions to their schemes not addressing the drivers of AGW, but the passive feedbacks, and/or discourages realistic and existing solutions in favour of unrealistic perfect (overthrow of the current economic and political system; changing of the human nature) – then yes – by their fruits we shall name them.
And the protestations of “unfair and immoral tactics” – from their mouths – rather rich.
Mo: “ It replaces reasoned debate with a punitive, “us vs. them” mentality”
Sure, because deniers are known to be fans of reasoned discussion, famous for being open to persuasion, and if you don’t call spade a spade – they would come around to our point of view.
Could you be specific – since you must do what you preach, i.e. are “fair and moral” – could you give several examples of the people whose minds you have changed?
The acceleration of the warming rate due to the removal of the aerosol “mask” is a temporary effect, but it leads to a new, permanently higher baseline warming rate per unit of CO₂ in the atmosphere.
The acceleration is the transition from a “masked” state to an “unmasked” state. Once the new lower aerosol levels are stable, the system will return to a more constant rate of warming, but that rate will be higher than the rate we experienced when aerosols were abundant. This is because the overall radiative forcing (the net change in Earth’s energy balance) is now greater. Less energy is being reflected back into space by aerosols, so more is being absorbed by greenhouse gases, leading to a consistently faster rise in global temperatures for the same level of CO₂ emissions.
The result is a permanent reset of the warming trajectory to a more aggressive pace, even if the “acceleration” itself is a temporary process of settling into that new, faster speed. This is basic climate science as described in every IPCC assessment. .
The decline in aerosols means that for every new tonne of CO₂ emitted, the resulting warming is more potent than it was when the aerosol mask was stronger. This makes the need to rapidly cut greenhouse gas emissions even more urgent.
Hansen’s work is very different. His group challenges the conventional approach of many mainstream climate models. He argues that because these models are “tuned” to match historical temperature records with an underestimated aerosol cooling effect, they may have an artificially low climate sensitivity. Hansen believes climate sensitivity is higher than the IPCC’s estimate.
Two different issues.
Mo Yunus “ The acceleration of the warming rate due to the removal of the aerosol “mask” is a temporary effect, but it leads to a new, permanently higher baseline warming rate per unit of CO₂ in the atmosphere.
Don’t think so. Let’s use formula: T(t) = at -b (1)
where T is the temp. anomaly in year “t” , “a”= the slope of warming due to CO2, and b= is the initial cooling effect of aerosols
– After we remove half of aerosols effect: T(t)= at – 0.5b (2)
The RATE of warming, dT/dt, =a in both cases! I.e. after a transient acceleration during the reduction of aerosols from b to 0.5b (2011-2020?) the AGW warming rate RETURNS to its pre-reduction rate (i.e. to “= a”). Ergo – NO “ permanently higher baseline warming rate” and NO “ permanent reset of the warming trajectory to a more aggressive pace – the pace is permanently the same before and after.
Mo: “This is basic climate science as described in every IPCC assessment.”
Again – your “higher warming rate” is NOT described in every IPCC assessment.”, but ONLY in your posts (see the formulas above).
But IF you WERE right – things would get only weirder – you would be implying that Hansen “discovered” …. what has been known and described by IPCC already for … 35 years (“the basic climate science described in every IPCC assessment”).
And why on Earth would Hansen then “believe climate sensitivity to be higher than … the IPCC’s estimate “??? Does he ever claimed that IPCC … does not use the “basic climate science as described in …. every IPCC assessment” ???
Curiouser and curiouser …
“The acceleration is the transition from a “masked” state to an “unmasked” state”. No it isn’t. These things have “relative quantitative effects”. An “unmasked” state” is either the same air as 1650-1750 at times of average volcanic activity (or it could be taken as humans removing 100% of all aerosols from the air).
The “masked” state has been continuously changing so it’s meaningless. Scientists try to figure out these quantities for the relevant things rather than stating stuff that’s unquantified and thus meaningless.
“Once the new lower aerosol levels are stable” looks a bit meaningless. Does it refer to the stratosphere where water isn’t washing the air non stop? Or is it a suggestion that humans are by and large highly unstable and might do any old random thing at any moment so need to wait until humans get stable? The latter is definitely correct.
In your opinion of this physical science do you think that the ocean has any effects at all? Or basically irrelevant?
I incorrectly assumed you had done with physical science attempts and noted your “higher baseline warming rate per unit of CO₂ in the atmosphere” seems OK. I should have finished reading because you have an incorrect “The decline in aerosols means that for every new tonne of CO₂ emitted, the resulting warming is more potent” (I don’t know why that incorrect physics wasn’t up with the correct bit so I’m trying to shift the blame for my multiple-comment SPAMming that got me banned for life from GoogleyTubes).
Mo, in your comment just above, you indicate a desire for a “thoughtful, evidence based conversation”, and “sharing knowledge”. But you seem reluctant to answer a question (which I asked you previously) that would certainly be helpful in educating readers about the science at the most basic level.
You say:
“the system will return to a more constant rate of warming, but that rate will be higher than the rate we experienced when aerosols were abundant. This is because the overall radiative forcing (the net change in Earth’s energy balance) is now greater. Less energy is being reflected back into space by aerosols, so more is being absorbed by greenhouse gases, leading to a consistently faster rise in global temperatures for the same level of CO₂ emissions.”
You contrast that with Hansen’s claim that the aerosols were historically reducing the net change in EEI more than assumed in the models, and so climate sensitivity is greater than the models predict.
But the question is this:
Both the “old” model(s), and the “new” model situation you describe, are based on EEI in projecting future conditions for *all* the elements of the climate system. So why, if we are looking for changes in trends, would we not use the measurement of EEI rather than “warming” or “climate sensitivity”??
EEI is the cause, and GMST is *one* of the effects, and not a very significant one in itself. Much of the confused “debate” we see here results from conflating the two.
“The technology (nuclear fusion), it’ll be on the electric grid, you know, in eight to 15 years.” – U.S. Dept. of Energy Secretary Chris Wright
“US energy chief tells BBC nuclear fusion will soon power the world”
Justin Rowlatt Climate Editor
12 September 2025
https://www.bbc.co.uk/news/articles/cqlz5p314z0o
“Don’t worry too much about planet-warming emissions, the US Energy Secretary has told the BBC, because within five years AI will have enabled the harnessing of nuclear fusion – the energy that powers the sun and stars.”
Need to check the U.K. Betting Houses for odds on this ;-)