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Unforced variations: May 2019

Filed under: — group @ 2 May 2019

This month’s open thread about climate science topics. For discussions about solutions and policy, please use the Forced Responses open thread.

161 Responses to “Unforced variations: May 2019”

  1. 1
    Ed Davies says:

    What would the temperature profile of an atmosphere without any greenhouse gasses be?

    Clearly the surface would be at the temperature set by the insolation and albedo and the atmosphere above would be at that temperature or lower. But how much lower?

    I think there’d be a lot less convection than is present in an atmosphere with greenhouse gasses but I’m not sure if it’d be isothermal and stable (i.e, there’d be no troposphere and the stratosphere would reach down to the ground) or would follow the normal lapse rate set by expansion and compression. Perhaps it depends on whether the atmosphere absorbs some of the incoming radiation so is warmed a bit from above (like Earth’s stratosphere) or not.

  2. 2
    nigelj says:

    Some new research relevant to the horrible, frustrating subject of climate denialism.

    It’s often been said that facts don’t convince doubters. According to my paper copy of Scientific American dated march 2019, in an article called “why we believe in conspiracy theories” (paraphrasing) research has traditionally suggested facts, logic and evidence don’t convince doubters, and just causes doubters to “dig their heels in deeper”, the so called “backfire effect”, but more recent research suggests this effect is rare.

    New research finds pointing out logical inconsistencies in conspiracy theories, and facts about political issues does help change people’s minds The research concludes backfire effect is more tenuous than previously thought. The backfire effect seems to happen mostly when people are challenged over ideas that define their their worldview and sense of self, so this is something to avoid doing.

    The article also showed how encouraging analytical thinking helps.

    So perhaps countering climate denialists with facts and evidence is not such a waste of time afterall. I have always had a strong instinct this is the case. Imho there will of course be a few people that will never change their minds on climate change (there is an actual flat earth society, and these guys are serious) but I would suggest this is a pretty small minority of people.

    And I totally recognise the power of vested interests and political ideology to push people to deny science, just that convincing at least some of them may not be as hopeless as we sometimes think.

    And personally I think pointing out logical fallacies important as well, and sadly something that was not always well executed by media in general and the science community in the earlier days of the climate change discussions.

  3. 3
    nigelj says:

    MAR and Snape. You guys make sense, and are clear to me. Ignore the mud slingers in their many forms.

  4. 4
    Omega Centauri says:

    Ed @1
    There would have to be some mechanism for the atmosphere to lose energy to space. If it were completely transparent to thermal radiation then the only thing it could be is in equilibrium with the surface. Planets do have regions that receive more radiation and regions that receive less, so the actual surface temps would vary.There would be some circulation thermals would appear over the warm areas, and there would be descending air over the colder regions (likely warm tropics, and colder polar regions). Rising air would still cool, and sinking air warm, that thermodynamics which wouldn’t disappear with the IR opacity. So there would be a bit of a troposphere, but without a heat sink on top.

  5. 5
  6. 6
    patrick027 says:

    re 1 Ed Davies

    With solar heating of the atmosphere, at least for a 1-dimensional equilibrium model with no forced mixing, the temperature would just rise with height. Without greenhouse gases and clouds, there is no absorption or emission of radiation within the atmosphere, so all the cooling to space has to be from emission at the surface. Conduction is not very effective in the atmosphere, so the lapse rate would presumably be negative and very large. Of course, if the atmosphere gets anywhere as near as hot as the sun, it would tend to emit a glow (assuming LTE, emissivity has to exist at the same frequencies that absorption occurs, in this case in SW frequencies). This sets aside any mechanically-forced mixing. I imagine there could be some very shallow convection near the surface due to spatial variations in solar heating… but I’m not sure at all how shallow… there could be other considerations…

  7. 7
    Erik Lindeberg says:

    My monthly question: What has happened to GRACE-FO? After the apparently successful launch almost a year ago, there are absolutely no data and no news. Their web site only comes with old stuff. The design life of the twin satellites is five years. Will there be four more years of silence? Anyone from NASA of GFZ who knows anything. JPL people?

  8. 8
    Ed Davies says:

    Thanks Omega & Patrick. Yes, convection from the tropics to the poles would likely be important. Also, any absorption of incoming radiation so maybe it’s a bit unrealistic to imagine that happening without at least a bit of radiation at thermal wavelengths – even if the gases don’t do it any particulates suspended in the atmosphere likely would.

    It just amuses me that a very few people deny the greenhouse effect completely when you can just point as cumulus clouds or snow capped mountains as counter evidence.

  9. 9
    Hank Roberts says:

    it doesn’t seem so outlandish to think that, as has happened more and more in recent years, we might outsource our world-saving imaginative tasks to the obscenely rich. Think the Gates Foundation and malaria, or Jeff Bezos giving new life to the Washington Post. The emergence of the private space flight industry could be seen as a sort of marker between the old and the new, a time when governments took on the biggest projects versus one when maybe those governments don’t quite have it in them anymore. Could geoengineering be next?

    “I think it is a plausible scenario,” says Janos Pasztor, the executive director of the Carnegie Climate Geoengineering Governance Initiative (C2G2), a group that takes no position on the should-we-or-shouldn’t-we question but instead is trying to guide the international community toward a system where those decisions are made carefully, and their aftermath is governed properly.

    Pasztor says that billionaires may well be capable of circumventing that sort of process.

    “First of all, the direct cost of solar radiation modification is likely to be quite low,” on the order of a few billion dollars per year, he says over Skype from Geneva. “You could actually envision quite a few individuals in this world who would be able to do that. Maybe some of them might decide that they just want to save the world—they do this all the time, rich people.”

    So imagine a scenario …

  10. 10
    patrick027 says:

    clarification (my #6): a 1000s+ K hot atmosphere with the same optical properties as Earth’s now in SW radiation could emit a solar-IR glow. But in such extreme conditions the optical properties would probably be different (I’d guess more molecular dissociation and ionization)… but anyway, that SW emission would allow a reduction in surface temperature as less heat has to reach the surface to escape to space.

    Adding some greenhouse effect, the instantaneous tropopause-level forcing (which is essentially surface forcing) would be positive, with increased downward LW flux; there would also be increased LW flux to space from the atmosphere, and this would be greater than the reduction caused by intercepting LW emission from the surface; hence stratospheric (essentially whole atmosphere) cooling, which would reduce the LW and SW emissions from the atmosphere to space and the surface.

    For a very small LW absorptivity, the whole atmosphere would be like a skin layer – that is, it would have such a small effect on outgoing LW radiation that the equilibrium surface temperature would still be the effective emitting temperature of the planet (isothermal blackbody approximation); the atmosphere in radiative equilibrium would absorb some very tiny fraction of that flux from the surface (including any LW reflection) and emit half that both upward and downward to space, along with half the solar heating upward and downward (assuming it is not hot enough to glow in SW – in that case the SW opacity and possible dominance of negative lapse rate may cause greater upward emission to space than downward). If the solar heating of the air matched the LW absorption from the surface, then the equilibrium air temperature would match the surface temperature (assuming a blackbody surface); zero solar heating would allow the atmospheric temperature to drop to somewhere between 0.5x and 1x the surface temperature (blackbody), depending on the LW spectrum – for graybody (absorptivity constant over LW portion of spectrum), it would be the fourth root of 1/2.

  11. 11
    barry says:

    A request for a post on atmospheric water vapour.

    As WV is considered to be a significant amplifier of CO2 warming, I went looking for observational studies on long-term atmospheric water vapour content. Results seem inconclusive, or maybe I don’t know the correct search terms to use. I’ve read hither and yon that total atmospheric WV has increased long term, but that’s been hard to corroborate.

    Also, has there been any development in assessing the predicted enhanced warming in the tropical mid-troposphere? Detection of that, too, appears to be uncertain as far as I can make out.

    Any pointers here much appreciated, but I hope RC has time to post a review of the state of knowledge of changes in atmospheric water vapour. It’s been more than 10 years, I think, since an post on these observations.

  12. 12
    Barry Finch says:

    Ed @1 Earth’s surface would be entirely white (it’s a “Snowball Earth”, it happened 600,000,000 years ago and perhaps a few previous times). I’ve been unable to find the percentages of incoming SWR absorbed by clouds, oxygen and anything else out of the total 22% so if I take 10% as an example for oxygen (you need to find the actual percentage) then 306 w / m**2 SWR reaches the surface and 34 w / m**2 SWR heats the oxygen (the atmosphere). Say ice/snow mix absorbs 15% then solar heating absorbed at surface is 45.9 w / m**2 (260.1 w / m**2 reflected back to space, Earth is a bright white marble). So Earth’s ecosphere absorbs ~80 w / m**2. I’m not searching the ice/snow emissivity for this, especially since I couldn’t find oxygen SWR absorption with a quick search. If it’s 0.96 for example then an average surface temperature of 196K balances that. So with my examples of oxygen absorbing 10% of SWR, 0.85 ice/snow albedo (15%) and 0.96 emissivity a Global Mean Surface Temperature (GMST) of -77 degrees (note: not -18 degrees because the WG1 climate scientists who said that didn’t know that ocean water would freeze at -1.8 degrees (except Peter Wadhams knows)). Atmospheric lapse rate would likely be -10 degrees / km altitude because no H2O vapour (or clouds, bone dry) but maybe would be slightly less because surface/air heating ratio of 58% rather than the present 68%. I’m really guessing now but perhaps it’s quite linear to that ratio with bone dry air (no water on Earth’s surface) so maybe -8.5 degrees / km altitude starting at the global surface/air mean of -77 degrees.

  13. 13
    Barry Finch says:

    Me @8 I just remembered something that occurred to me a while back that I forgot just now. If the atmosphere has no gases that emit LWR (a hypothetical Earth without volcanoes) then it can only cool to balance the oxygen absorption of solar LWR by sensible heat (conduction) to the surface. I did have the full ~80 w / m**2 emitted to space from the ice/snow surface but the sensible heat (conduction) to the surface implies a negative lapse rate, I think. I can’t do any more ad hoc thinking about that.

  14. 14

    #2, nigel–

    I have no research basis whatever for this, but FWIW, I think it’s not just the provision of facts and logic that determines the occurrence of a backfire effect; it’s also highly dependent upon the mode of provision of such in relation to the situation of the ‘receiver’. You’ve mentioned already the subjective condition of the receiver: their “their worldview and sense of self.” And we all know–again, as you mention–cases where the receiver is so entrenched that actual “reception” is ruled out completely.

    But there’s also the dynamic between the “sender” and the receiver to consider. Anyone who reads here recurrently will have witnessed what some call the “conflict cycle”, in which discourse becomes increasingly polarized and emotional. We’ve all seen it, and most of us have done it–certainly I have. That’s because it’s exceedingly common among h. sap. It’s worth keeping in mind because that’s the portion of the process that one actually has (in principle, at least) some control over. It’s non-trivial to do, but the more one can maintain equanimity, the more likely one is to be heard.

    In practical terms, the best way I know to do that is to keep listening. After all, in any true conversation, both parties are “senders” and “receivers”. I’ve found that if I can keep truly listening, I will be less inclined to be drawn into the conflict cycle. That’s not to say that I have a 100% success rate in doing so, of course. But it is the most powerful tool that I know.

    This is deeply related to the famed Socratic method, of course. IMO, the latter is sometimes framed more as a clever ‘ambush technique’ to get around cognitive defenses, and I suppose that ‘works’ sometimes. But I suspect that the real Socrates–about whom almost everything we know comes indirectly via Plato, IIRC–probably asked a great many of his questions with complete sincerity, and was actually open to the answers he received.

  15. 15
    Carrie says:

    Comments updates still a drag I see.

    7 Erik Lindeberg, good question about silence. Whatever happened to the OCO-2 updates? Been 2-3 years of silence there too since 2015/16 data from NASA. Did it die? Maybe Gavin cold enquire of his coworkers one day and share the news here or on twitter?

  16. 16
    Carrie says:

    Hi Killian, responding to your late april comments (and et al).

    Recent Daily Average Mauna Loa CO2 tracking at +414 ppm as we head into the annual maximum in May.

    Recent Monthly Average Mauna Loa CO2 diary

    APRIL estimate: 413.59 +3.35 ppm
    March 2019: 411.97 ppm + 2.56 ppm
    February 2019: 411.75 ppm +3.43
    January 2019: 410.83 ppm +2.87 PPM
    Dec 2018 409.07 PPM +2.26
    NOV 2018 408.02 ppm +2.90 ppm
    OCT 2018 406.00 ppm +2.37

    7 months avg MLO CO2 growth +2.82 ppm
    last 4 mths avg growth Jan-April +3.05 ppm
    current daily avg 414.40 ppm, +3.15 ppm

    BOM still not declaring any El Nino in the last 7 months either.

    30 April 2019 – The Bureau’s ENSO Outlook remains at El Niño ALERT. This means the chance of El Niño developing in 2019 is approximately 70%. Climate models indicate that if El Niño does develop it is likely to be short-lived.

    Kind of puts a different slant on MAR’s cherry picking and blind spots?

    Scripps currently shows it as 415.09ppm for May 3rd – and it’s not being driven by an El Nino event.

    So from where is all this CO2 coming from? National emissions data is unreliable and prone to incompetence and manipulation (and always delayed.) Nothing from OCO-2 so who knows what the natural sources may be doing the last 12 months to now. The the only measurement worth it’s salt is atmospheric PPM readings done daily.

    January 2019: 409.78 ppm +2.48
    January 2018: 407.30 ppm

    December 2018: 409.36 ppm +2.83
    December 2017: 406.53 ppm

    November 2018: 408.16 ppm +2.68
    November 2017: 405.48 ppm
    Last updated: April 12, 2019

    February & March could be a cracker. ASI & Greenland already is.

    On Hansen et al “Even the speculations of Hansen et al (2015) only reckoned to 5m.” (by 2100)

    Yeah? Well if that works out ‘correct’ when does +2 metres arrive? Will not be pretty, Doh!

    Hansen’s Ice melt 2015 paper is pretty good. Pity too many people ‘abuse’ it so flamboyantly while ignoring the knowledge within it. e.g.
    Ice melt, sea level rise and superstorms:

    6.2 Southern Ocean, CO2 control knob, and ice sheet timescale
    Our climate simulations and analysis of paleoclimate oscillations indicate that the Southern Ocean has the leading role in global climate change, with the North Atlantic a supporting actor.

    The Southern Ocean dominates by controlling ventilation of the deep-ocean CO2 reservoir. CO2is the control knob that regulates global temperature.

    On short timescales, i.e., fixed surface climate, CO2 sets atmospheric temperature because CO2 is stable ; thus, the ephemeral radiative constituents, H2O and clouds, adjust to CO2 amount (Lacis et al., 2010, 2013).

    Here we must clarify that ice and snow cover are both a consequence of global temperature change, generally responding to the CO2 control knob, but also a mechanism for global climate change.

    The most important practical implication of this “control knob” analysis is realization that the timescale for ice sheet change in Earth’s natural history has been set by CO2, not by ice physics.

    With the rapid large increase in CO2 expected this century, we have no assurance that large ice sheet response will not occur on the century timescale or even faster.

    6.9 Practical implications
    First, our conclusions suggest that a target of limiting global warming to 2?C, which has sometimes been dis-cussed, does not provide safety. We cannot be certain that multi-meter sea level rise will occur if we allow global warm-ing of 2?C. However, we know the warming would remain present for many centuries…

    We observe accelerating mass losses from the Greenland and Antarctic ice sheets, and we have identified amplifying feed-backs that will increase the rates of change.

    We conclude that, in the common meaning of the word danger, 2?C global warming is dangerous.

    Second, our study suggests that global surface air temperature, although an important diagnostic, is a flawed metric of planetary “health”

    The UNFCCC never mentions temperature– instead it mentions stabilization of greenhouse gas concentrations at a level to avoid danger.

    CO2, must be reduced to no more than 350 ppm to restore planetary energy balance (Hansenet al., 2008) and keep climate near the Holocene level, if other forcings remain unchanged.

    Third, not only do we see evidence of changes beginning to happen (before 2015) in the climate system, as discussed above, but we have also associated these changes with amplifying feedback processes.

    … a system in which major components such as the ocean and ice sheets have great inertia but are beginning to change, the existence of such amplifying feedbacks presents a situation of great concern.

    We conclude that the message our climate science delivers to society, policymakers, and the public alike is this: we have a global emergency. Fossil fuel CO2 emissions should be reduced as rapidly as practical.

    (end quotes)

    Takeaway message? CO2/CO2e Rules the Day – period!

    96 Responses to “Unforced variations: April 2019”

    Is that a new all time record low? I think it is. I wonder why that is? :-)

  17. 17
    Carrie says:

    REPOST from January ….

    63 mike says:
    10 Jan 2019 at 6:58 PM

    for MAR: Hey, Al. Can you post your analysis (or link thereto) that shows slowing of the CO2 accumulation that relates to the 2014-2017 emission slowdown over at Tamino’s thread on CO2 buildup please?

    Thanks Mike

    56 Carrie Kant says:
    9 Jan 2019 at 10:23 PM

    The avg Global Growth rate from May thru Sept has been + 2.546 ppmv YoY

    Wait until the next El Nino hits and see how high it goes then. +4.00 ppm is not out of the question. 2018 is already streets ahead of the last El Nino years 2015/2016 .. and I mean WAY UP.

    So I will ask this very simple question… “WHAT CO2 EMISSIONS REDUCTIONS?” There aren’t any doh!

    2018 ~2.50 New GLOBAL Growth Rate Record for a Non-El Nino Year

    MLO CO2 is already hitting +3.43 February ’19; and +3.35 ppm April ’19 with no El Nino driving those numbers that high.

    Obviously, +4 ppm during an actual El Nino will be shit easy; and +5 ppm not out of the question either.

  18. 18
    Carrie says:

    Hey Killian … Greenland melt season officially starts almost a month early

    May 3rd, 2019

    Today DMI scientists announced the start of the Greenland melt season, the second earliest in a record that stretches back to 1980. “The start of the melt season occurs on the first of three consecutive days where more than 5% of the ice sheet has melt at the surface.” said scientist Peter Langen. “We use a pretty strict definition as we want to make sure it is a consistent start to melting and not just a blip due to unseasonal weather”. This year’s start of 30th April is second only to 2016 [the super-el nino period ], when a very unusual weather pattern caused a very early start to the melt season in mid-April.

    West Greenland forecast exceeds 16’C today .. 20’C tomorrow .. and 16’C monday and Tuesday .. they have made it warm in Greenland !

    “What apparently is happening is that greenhouse gases are speeding up the Brewer Dobson circulation – the flow of air from the troposphere to the stratosphere and back. In this case is is causing subsidence over Greenland, the Beaufort sea and the high Arctic. This is why, barring the lucky occurrence of cool cloudy stormy July, I think we are likely to see a new record sea ice minimum this September.”

  19. 19
    Hank Roberts says:

    A new study of warm seawater seeping into a cavity below the Ross Ice Shelf shows that a key section of the France-size hunk of ice is melting much faster than the rest.

    “We’ve identified an especially vulnerable section where the melt rate is 10 times higher than the rest of the ice shelf,” said study co-author Poul Christoffersen, a glaciologist at the University of Cambridge’s Scott Polar Research Institute. The Ross Ice Shelf is considered relatively stable, but Christoffersen said the location of the rapid melting coincided with a “pinning point” — essentially a buttress that holds back flowing ice and lends stability to the entire shelf….

  20. 20
    Hank Roberts says:


    Ice–ocean interactions at the bases of Antarctic ice shelves are rarely observed, yet have a profound influence on ice sheet evolution and stability. Ice sheet models are highly sensitive to assumed ice shelf basal melt rates; however, there are few direct observations of basal melting or the oceanographic processes that drive it, and consequently our understanding of these interactions remains limited. Here we use in situ observations from the Ross Ice Shelf to examine the oceanographic processes that drive basal ablation of the world’s largest ice shelf. We show that basal melt rates beneath a thin and structurally important part of the shelf are an order of magnitude higher than the shelf-wide average. This melting is strongly influenced by a seasonal inflow of solar-heated surface water from the adjacent Ross Sea Polynya that downwells into the ice shelf cavity, nearly tripling basal melt rates during summer. Melting driven by this frequently overlooked process is expected to increase with predicted surface warming. We infer that solar heat absorbed in ice-front polynyas can make an important contribution to the present-day mass balance of ice shelves, and potentially impact their future stability.

  21. 21
    Hank Roberts says:

    Young and another researcher at the university took a close look at data collected by 31 wind- and wave-measuring satellites launched into space by NASA, the European Space Agency and other organizations. The researchers compiled 4 billion measurements collected between 1985 and 2018 and checked them against data from 80 buoys floating in oceans around the world.

    The numbers paint a picture of strong winds getting stronger and big waves getting bigger — particularly in the Southern Ocean around Antarctica. Between 1985 and 2018, the fastest winds over the Southern Ocean became 8 percent faster, speeding up by about 3.4 miles per hour. Over the same time period, those winds drove the highest waves almost a foot — or five percent — higher.

  22. 22
    AndyG says:

    Erik: per wiki, Grace-FO had some trouble with its instrument and wasn’t operational until the end of Jan 2019. Sites and schedules for the data are in one of the recent linked references, here:

  23. 23
    Carrie says:

    Killian, to finish above comments with the final MLO figures for last week.

    Up-to-date weekly average CO2 at Mauna Loa
    Week beginning on April 28, 2019: 414.32 ppm +4.48
    Weekly value from 1 year ago: 409.84 ppm
    Weekly value from 10 years ago: 390.36 ppm
    Last updated: May 5, 2019

    oh, btw, a MLO CO2 YoY growth rate of +4.48 is new all time record!

    And with no El Nino operating in the Pacific, based on the experts at the BOM Australia, that’s some achievement by mankind.

  24. 24
    MA Rodger says:

    Barry Finch @12/13,
    Some thoughts….

    When considering the temperature resulting from the theoretical removal of all GHGs from the atmosphere, there is perhaps a bit of a conundrum to solve. As you say, albedo will be a big input to the outcome yet if that albedo is set by water ice perhaps with a “bright white marble” finish, there is the consideration of water melting under the noon-day tropical sun and this resulting in significant levels of atmospheric water vapour. Lacis et al (2010) shows atmospheric H2O at 10% of today’s levels.

    Yet taking that situation forward many mnay thousands of years, the evaporated of water in the tropics would surely, as in ice ages, partly fall as snow at latitudes where it would not melt and thus accumulate there until the tropics become an ice/water-free desert and the atmospheric H2O level drops to zero. Water as ice thus becomes part of the planet’s geology.

    Of course, without water the geological processes are a lot more restricted, rock forming driven by just volcanic/tectonic processes. Surface ice will be refreshed with fresh snow when volcanic actions melt it. But the tropical deserts will presumably remain and thus these important latitudes will not have a “bright white marble” surface so the planet’s albedo will thus be much lower.

  25. 25
    mike says:

    Guardian headline: ‘We are in trouble’ / Human society under urgent threat from loss of Earth’s natural life

    “David Obura, one of the main authors on the report and a global authority on corals, said: “We tried to document how far in trouble we are to focus people’s minds, but also to say it is not too late if we put a huge amount into transformational behavioural change. This is fundamental to humanity. We are not just talking about nice species out there; this is our life-support system.””

    David Obura sounds like he is getting a little woundup about the matter.



  26. 26
    mike says:

    April 28 – May 4, 2019 414.32 ppm
    April 28 – May 4, 2018 409.84 ppm

    4.48 ppm increase in yoy numbers. It’s a signal with a bunch of noise, but most of us would probably prefer to see a noisy number on the lower end of the range. Increase average over the past ten years is just under 24 ppm.

    I am told we are making progress on this matter, so no worries.



  27. 27
    TPaine says:

    Omega, Patrick, Barry

    I’m no climate scientists but I have tried to educate myself as much as I am capable of without a climate science education. So I’m just asking the question. I took an online climate science class where they described how the Stefan-Boltzmann equation was used to calculate the temperature of the earth. Since that equation does not include the effect of greenhouse gases, they subtracted that calculated temperature from the actual temperature of the earth to determine the greenhouse gas effect. Sounded scientific to me. If that was accurate, why wouldn’t the temperature of the earth without greenhouse gases be just the temperature calculated with the Stefan-Boltzmann equation?

  28. 28
    patrick027 says:

    Re 27 TPaine – my posts above were just about the atmospheric temps relative to the surface; you are correct: the surface itself – at least in the isothermal approximation (same temp all over the globe) – would be determined by the Stefan-Boltzmann equation, so that sigma*T^4 = global average absorbed solar irradiance, in the absence of a greenhouse effect and assuming the surface is a blackbody in LW (for Earthly conditions, wavelengths longer than ~ 4 microns) (which is true to a first-approximation; there is some LW reflection; the impression I’ve gotten so far (I only recently found information about this) is that this is more near the short-wavelength end of LW).

  29. 29
    patrick027 says:

    I found a really cool graph of gaseous spectra – specifically, this is zenith (vertical) optical path (transmittance = exp(-optical path)) for the whole atmosphere (optical path adds linearly so the presence of clouds, etc, wouldn’t affect this, although surface pressure, humidity, etc… I haven’t figured out exactly which conditions this is for but I presume it’s common Earthly conditions with a recent value of GHG abundances?: – you can click and drag within the graph to zoom in spectrally and slide along it using the tool below. You can click on a subset of the gases to focus on the info you want. (PS remember that H2O is concentrated low in the atmosphere relative to atmospheric gases as a whole, so I expect CO2 would dominate over a wider band higher up.)

    That said, I’ve become curious about some features –

    CO2 – what’s the difference (absorption mech) between the tall prominent spikes and the more common spikes with narrower spacing (and why do the prominent ones lean to one side or another?)

    I’ve gotten used to the idea of narrow spikes separated by ~U shaped valleys (as if carved by glaciers! :) ) as a result of lines and the broadening of them. What’s up with the ‘slot canyons’ in H2O near 12.1 microns?

    I’m guessing that the absorption by molecules like O2 and N2 (very weak, of course) (yeah, the exactly-zero GHE scenario would be hard to achieve) is due to spontaneous and/or induced polarization? But the N2 band (near 4 microns) looks strange – a broad, relatively smooth plateau with steep drop-offs on the sides… weird – or is it? – I’m no expert on this stuff.

  30. 30
    Hank Roberts says:

    Time to revise some models?

    … permafrost is likely to release up to 50 per cent more greenhouse gases than climate scientists have believed. As well, much of it will be released as methane, which is about 30 times more potent as a heat-trapping gas than carbon dioxide.

    “These are minimum estimates,” Turetsky said. “We’ve been very conservative.”

  31. 31
    Hank Roberts says:

    For TPaine:

    Multiplying the energy emissions per unit area times the surface area of Earth, we derive an expression for Earth’s total infrared energy emissions …
    … Based on this calculation, Earth’s expected average global temperature is well below the freezing point of water!

    Earth’s actual average global temperature is around 14° C (57° F). Our planet is warmer than predicted by 34° C (60° F). That’s a pretty big difference!

    Greenhouse EffectWhy is Earth’s temperature so much warmer than our calculations predicted?…

  32. 32
    Barry Finch says:

    TPaine @27 Yes Stefan-Boltzmann as far as it goes but I decided to alter the topic completely from what Ed @1 was really interested in thinking about (lapse rate) and point out the vast +ve feedback ignored with real Earth we are on with the “33 degrees colder” simplified illustration used by scientists because they don’t want to have everybody confused by its complication when they are only saying to the general public the simple reality that an Earth at its present orbit would be 33 degrees colder (excluding any feedbacks) without atmospheric greenhouse gases (GHGs) and there’s no other explanation ever found for that.

    It just always amused/bemused me that it’s oft repeated without anybody apparently twigging that the ocean surface water will most definitely freeze at -18 degrees Global Mean Surface Temperature (GMST) and the massive albedo increase (far more radiation reflected back to space) will approximately double or more the 33 degrees of cooling calculated with the Stefan-Boltzmann equation for a dry planet or a planet coated with a liquid that doesn’t turn a nice white when it solidifies.

    MA Rodger @24 Thanks for the link. I’ll be studying that pdf document that I haven’t seen before some time when my brain feels like thinking. Yes I didn’t think of tropical melt ponds though I did idly wonder once whether the final “Snowball Earth” deglaciation with whatever CO2 it had and Tropical Amplification (what happens at the equator doesn’t stay at the equator) when the Tropical Blue Ocean Event (TBOE) happened was the most recent previous time before this century (later) when GMST rose >2.0 degrees in <2,000 years. I'm finding it difficult to find anything else that's physically capable of doing it (I mean apart from the proto-Earth collision that warmed it a bit to a vapour and formed Earth).

  33. 33
    Ray Ladbury says:

    The Stefan-Boltzmann equation applies specifically to an idealzed absorber/emitter–that is a perfect black body that absorbs all radiation incident upon it. These don’t exist in real life, so there are some fudge factors for real materials.

  34. 34


    Without an atmosphere, if everything stayed the same so the reflectivity didn’t change, the Earth’s atmosphere would be 255 K. They’re arguing how the surface would change.

  35. 35
    MA Rodger says:

    Oh dear. Another flavour of hockey stick has been uncovered by Freund et al (2019) ‘Higher frequency of Central Pacific El Niño events in recent decades relative to past centuries’. The paper is paywalled but the authors have written an account for The Conversation.

    “The pattern of El Niño has changed dramatically in recent years, according to the first seasonal record distinguishing different types of El Niño events over the last 400 years.
    “A new category of El Niño has become far more prevalent in the last few decades than at any time in the past four centuries. Over the same period, traditional El Niño events have become more intense.”

  36. 36
    TPaine says:

    Can someone tell me the relationship between weather, hurricane, and climate models. I had read that hurricane and climate models were based on and modifications of weather models. Is that accurate?

    BTW I’ve followed climate change websites for several years now including RealClimate. But I have always just glanced at RealClimate because it didn’t seem to change much over the days and weeks. But recently I’ve started reading the posts in the variations and have discovered there is a wealth of valuable information from all the participants. And most of the posters are very educated on the subject. So thinks to everyone for taking the time to post.

  37. 37
    Nick Palmer says:

    Watts and his followers are currently crowing about the paper from NOAA which, Watts claims, validates his Surface Stations project and that the temperature records are therefore duff as he has always said…

  38. 38
    Barry Finch says:

    35 @MA Rodger: I need to immediately do that thing Paul Beckwith does where he says he invented it. I never pondered a hook though. HellNino for now. This in varied versions I’ve been posting for 5 years in video comments with never any response. This is cut’n’paste. Because the air is coupled (can blow west across South America) but the ocean is blocked by South America there’s an effect and Paul is showing you a profound thing about Global Mean Surface Temperature (GMST) increase (El Nino is “pulling away” since 1990 AD) and the famous 2002-2015 GMST “pause” or “hiatus” slowing. I studied it 5 years ago. Here it is, about the mighty ENSO & GMST.
    The tropical Atlantic Ocean surface warming has intensified Pacific Ocean easterly Trade Winds since 1990 AD. It’s known that Pacific Ocean easterly Trade Winds have been strengthening for a couple of decades & that’s a major reason for the GMST “pause” or hiatus. Pacific Ocean easterly Trade Winds have increased their average speed by 1 m / s since 1990 AD when the acceleration started, increased by 50% in under 30 years (ENSO is strengthening). The tropical Atlantic has warmed and has increased the intensity of the Pacific Ocean easterly Trade Winds.
    I plotted GMST from GISTEMP for 50 years on a big sheet of graph paper 5 years ago and it’s:
    If you plot the El Nino years only, which are 1966, 1969, 1973, 1977, 1978, 1980, 1987, 1995, 1997, 1998, 2003, 2005, 2007, 2010 you clearly see a warming trend of 0.20 – 0.22 degrees / decade 1966-2010
    If you plot the La Nina years only, which are 1967, 1968, 1971, 1974, 1975, 1976, 1985, 1989, 1991, 1996, 1999, 2000, 2001, 2008, 2009, 2011, 2012 you clearly see a warming trend of 0.165 degrees / decade 1967-2012
    If you plot the ENSO-neutral years only (middling between La Nina & El Nino) which are 1970, 1972, 1979, 1981, 1986, 1988, 1990, 2002, 2004, 2006, 2013 you clearly see a warming trend of 0.165 degrees / decade 1970-2013
    (I skipped El Chichon, Mt. Pinatubo, Mt. Hudson years 1982-4, 1992-4)
    El Nino years trend line looks to be ~0.13 degrees warmer than La Nina years.
    El Nino years looks to be pulling away from La Nina years a bit since 1990 at 0.22 degrees / decade but it’s few measurements and they don’t form a tidy line at all.
    +0.165 degrees / decade 1966-1990 for La Nina & ENSO-neutral years
    ~+0.20 degrees / decade 1966-1990 for El Nino years
    +0.165 degrees / decade 1990-2014 for La Nina & ENSO-neutral years
    ~+0.22 degrees / decade 1990-2014 for El Nino years
    The reason why El Nino years have an approximation is that I used calendar years and El Nino doesn’t last precisely 1 calendar year. I haven’t found time yet to do it precisely.
    Scientist quote: A Shift in Western Tropical Pacific Sea Level Trends during the 1990s Mark A. Merrifield University of Hawaii at Manoa, Honolulu, Hawaii “Pacific Ocean sea surface height trends from satellite altimeter observations for 1993–2009 are examined in the context of longer tide gauge records and wind stress patterns. The dominant regional trends are high rates in the western tropical Pacific and minimal to negative rates in the eastern Pacific, particularly off North America. Interannual sea level variations associated with El Niño–Southern Oscillation events do not account for these trends. In the western tropical Pacific, tide gauge records indicate that the recent high rates represent a significant trend increase in the early 1990s relative to the preceding 40 years. This sea level trend shift in the western Pacific corresponds to an intensification of the easterly trade winds across the tropical Pacific. The wind change appears to be distinct from climate variations centered in the North Pacific, such as the Pacific decadal oscillation”.
    Scientist quote: “Atlantic warming turbocharges Pacific trade winds Date:August 3, 2014 Source:University of New South Wales. New research has found rapid warming of the Atlantic Ocean, likely caused by global warming, has turbocharged Pacific Equatorial trade winds. Currently the winds are at a level never before seen on observed records, which extend back to the 1860s. The increase in these winds has caused eastern tropical Pacific cooling, amplified the Californian drought, accelerated sea level rise three times faster than the global average in the Western Pacific and has slowed the rise of global average surface temperatures since 2001. It may even be responsible for making El Nino events less common over the past decade due to its cooling impact on ocean surface temperatures in the eastern Pacific. “We were surprised to find the main cause of the Pacific climate trends of the past 20 years had its origin in the Atlantic Ocean,” said co-lead author Dr Shayne McGregor from the ARC Centre of Excellence for Climate System Science (ARCCSS) at the University of New South Wales.”
    Scientist quote: “The record-breaking increase in Pacific Equatorial trade winds over the past 20 years had, until now, baffled researchers. Originally, this trade wind intensification was considered to be a response to Pacific decadal variability. However, the strength of the winds was much more powerful than expected due to the changes in Pacific sea surface temperature. Another riddle was that previous research indicated that under global warming scenarios Pacific Equatorial Trade winds would slow down over the coming century. The solution was found in the rapid warming of the Atlantic Ocean basin, which has created unexpected pressure differences between the Atlantic and Pacific. This has produced wind anomalies that have given Pacific Equatorial trade winds an additional big push. “The rapid warming of the Atlantic Ocean created high pressure zones in the upper atmosphere over that basin and low pressure zones close to the surface of the ocean,” says Professor Axel Timmermann, co-lead and corresponding author from the University of Hawaii. “The rising air parcels, over the Atlantic eventually sink over the eastern tropical Pacific, thus creating higher surface pressure there. The enormous pressure see-saw with high pressure in the Pacific and low pressure in the Atlantic gave the Pacific trade winds an extra kick, amplifying their strength. It’s like giving a playground roundabout an extra push as it spins past.” Many climate models appear to have underestimated the magnitude of the coupling between the two ocean basins, which may explain why they struggled to produce the recent increase in Pacific Equatorial trade wind trends. While active, the stronger Equatorial trade winds have caused far greater overturning of ocean water in the West Pacific, pushing more atmospheric heat into the ocean, as shown by co-author and ARCCSS Chief Investigator Professor Matthew England earlier this year. This increased overturning appears to explain much of the recent slowdown in the rise of global average surface temperatures. Importantly, the researchers don’t expect the current pressure difference between the two ocean basins to last. When it does end, they expect to see some rapid changes, including a sudden acceleration of global average surface temperatures. “It will be difficult to predict when the Pacific cooling trend and its contribution to the global hiatus in surface temperatures will come to an end,” Professor England says.”
    I assume it’s proportional to average tropical Atlantic Ocean temperature higher than tropical Pacific Ocean temperature or some related factor such as higher than eastern Pacific Ocean, or less lower than it usually is. Also, I’ve read a paper and seen a chart in a climate scientist’s talk that Easterly Trade wind increased 1.0 m/s since 1990 but I’ve not been able to locate it again. It refers to “wind stress” and has a plot that has almost zero change until 1990 then it increases linearly until now. (2014 when I did this).

    Keep your eye on this difference between GMST during the big El Ninos and see whether they do keep getting even higher peaks of heat causing problems this century.

  39. 39
    scott says:

    Re #2: “I have always had a strong instinct this is the case. Imho there will of course be a few people that will never change their minds on climate change (there is an actual flat earth society, and these guys are serious) but I would suggest this is a pretty small minority of people.”

    You assume that denialists are capable of rational thinking.

    From the above link it is clear that 42 percent of the American Public
    have no capacity to do so.

  40. 40
    MA Rodger says:

    Barry Finch @38,
    Your three “Scientist quotes” are from:-
    (i) Merrifield (2010) ‘A shift in western tropical Pacific sea-level trends during the1990s’.
    (ii) & (iii) Quoted from here but citing McGregor et al (2014) ‘Recent Walker Circulation strengthening and Pacific cooling amplified by Atlantic warming ‘.
    From a quick scan, Figs 4 & 5 in Merrifield (2010) are interesting in that, while SOI (when de-wobbled) shows a strong 1990-2016 rising trend, that is not away from previous levels, yet Merrifield is showing sea level with a strong rising trend away from previous levels.

  41. 41

    TPaine, #36–

    Can someone tell me the relationship between weather, hurricane, and climate models. I had read that hurricane and climate models were based on and modifications of weather models. Is that accurate?

    The short answer is “yes”–historically, the first predictive numerical models were developed with an eye on weather prediction as well as research. Climate models followed on from there. (I haven’t heard of models specifically designed to study hurricanes, and a quick Google search didn’t turn up examples–just studies using regular weather/climate models to study hurricane behavior. But I’m not sufficiently expert as to dare to assert that such don’t exist.)

    And all of these models use the same “primitive equations” of meteorology, which originated with Vilhelm Bjerknes, early in the 20th century:

    Expanding slightly on that, “climate models” may be vastly more involved than ones meant for operational weather forecasting because some of them attempt to account for all manner of processes that are not necessary to consider over the (much) shorter time horizons of weather models–for instance, modeling the carbon cycle.

    A great book on the development of climate modeling is Paul Edward’s “A Vast Machine”, which was recommended to me by a commenter here a couple of years ago. Highly recommended.

    There’s also a quick but useful summary of just the historical aspect here:

  42. 42
    nigelj says:

    Regarding 38# very useful information. Global warming is pushing heat energy into the oceans and evidence now suggests el ninos are becoming more intense. Who would have thought? El ninos cause additional CO2 emissions, so its all another positive feedback to add to the long and depressing list.

  43. 43
    Barry Finch says:

    @37 Nick Palmer Of course it’s all interesting and correct to study but my initial thought is whether it includes a section on poor siting near trash bins, cafes & airports in the North Pacific, South Pacific, North Atlantic, South Atlantic, Southern, Indian & Arctic Oceans. Especially the Urban Heat Island effect of the Great Pacific Plastic Garbage Patch which people keep telling me is actually an Island. Sorry.

  44. 44
    mike says:

    for MAR: I asked you at 81 in April UV comments about your thoughts on Crowther’s assertion that a portion of increases in CO2 emissions come from thawing permafrost. Did you answer? Did I miss that?

    I also think you have been resistant to such a possibility in the past. Here are a couple of links:

    I request that the RC scientists add a thread specific to the question of melting permafrost. I know we should not get wound up or unduly worried about the buildup of CO2 and CO2e and the warming that comes with it, but I like to hear it from the experts who do the science on a regular basis in addition to the calm folks who hang around and post comments here.

    Nothing to worry about, right?

    Noisy number report:

    Daily CO2

    May 8, 2019: 414.50 ppm
    May 8, 2018: 410.09 ppm

    4.41 ppm yoy, but so what?

    Cheers and warm regards to you all,


  45. 45
    Killian says:

    An interesting resource for sorting climate reporting fact from fiction, all done for you. (Cross-posted to both forums, and this version spellchecked.)

  46. 46
    Killian says:

    Important information for understanding the functioning of the carbon cycle; implications for modeling carbon sinks.

    pdf warning.

  47. 47
    TPaine says:

    Kevin, #41

    Thank you Kevin for the information. I was really interested in whether the different models used the same basic equations.

    I downloaded the book you recommended and look forward to reading it. The reviews looked like it was very informative.

  48. 48
    Snape says:

    Barry Finch @38

    The Atlantic has been warming gradually, over many decades, so why did the trade winds start to gain strength at such a specific date (1990)? If the answer involves “abrupt climate change”, OK, but there should be a mechanism to explain the abruptness.

  49. 49
    MA Rodger says:

    RSS has posted the April 2019 TLT anomaly at +0.78ºC. As with UAH, this is a step up on the previous months of 2019 Jan (+0.67ºC), Feb (+0.66ºC) and Mar (+0.72ºC). April 2019 is the 3rd warmest April in the RSS TLT record, sitting below April 2016 (+0.98ºC) & 1998 (+0.89ºC), and above April 2010 (+0.62ºC) & 2005 (+0.57ºC), all of these strong El Niño years, & April 2017 (+0.57ºC)
    April 2019 is 9th warmest month in the RSS TLT all-month record (=24th in UAH).
    As a start-of-the-year, Jan-to-April 2019 averages +0.71ºC, the =2nd warmest Jan-to-Apr on record (in UAH it is 4th) behind El Niño year 2016 (+1.00ºC), equalling 1998 (+0.71ºC) while ahead of 2010 (+0.69ºC), 2017 (+0.62ºC) & 2007/2018 both (+0.52ºC).
    These start-of-the-year values compare with the full calendar year values 2016 (+0.78ºC), 2017 (+0.66ºC), 2010 (+0.61ºC) & 1998/2015 both (+0.58ºC). With the weak El Niño still predicted to continue to influence the rest of 2019’s global temperatures, 2019 continues to look like becoming the second warmest year on record.

  50. 50
    MA Rodger says:

    mike @44,
    I think if you re-visit #81 in April’s UV thread, you will see that you asked no such question. Instead you address my comment @73 by repeating the message from a source that I had actually already debunked @73.
    The question you did ask @81 was “So, I guess I will ask you, in your terms, are you really not alarmed about the climate change that you observe sitting well within the science?” Do you want an answer to that? Or would you prefer a discussion of what actually lies behind Crowther’s assertions that thawing soils are “accelerating climate change about 12 to 15 percent at the moment”? (The supporting paper is presumably Crowther et al (2016) ‘Quantifying global soil carbon losses in response to warming’ which I haven’t read but does seem to be grossly misrepresented by Crowther’s “12 to 15 percent at the moment” statement.)