Global CO2 and temperature: 66 million years of climate data shows CO2 is already above 1.5C warming, we just haven't felt it, yet
Tom Goreau
Toward a Cenozoic history of atmospheric CO2, 2023, Science, 382:1136 summarizes 66 million years of global temperature and CO2 data.
The full paper is at: https://doi.org/10.1126/science.adi5177
The following figure tells the story based on real world data, not on idealized models by IPCC or anyone else that fail to capture the key natural feedbacks and stochastic events in the real world, see: https://www.globalcoral.org/bad-science-and-good-intentions-prevent-effective-climate-action/
The PRESENT CO2 level corresponds to around +4C warming when all the unrealized warming from feedback loop time delays play out, what Hansen refers to as warming in the pipeline, and which most prefer to pretend does not exist (magical thinking that places them in the Santa Claus, Tooth Fairy, Easter Bunny, Naked Emperor, and OPEC+Trump Club).
This means the cdr removal needed to stabilize climate at safe levels is to preindustrial GHG levels (T. J. Goreau, 1987, The other half of the global carbon dioxide problem, NATURE, 328: 581-582; T. J. Goreau, 1990, Balancing atmospheric carbon dioxide, AMBIO, 19: 230-236; Hansen, J.E., M. Sato, L. Simons, L.S. Nazarenko, I. Sangha, P. Kharecha, J.C. Zachos, K. von Schuckmann, N.G. Loeb, M.B. Osman, Q. Jin, G. Tselioudis, E. Jeong, A. Lacis, R. Ruedy, G. Russell, J. Cao, and J. Li, 2023: Global warming in the pipeline. Oxford Open Clim. Change, 3, no. 1, kgad008, doi:10.1093/oxfclm/kgad008.)
This is the REAL science of climate change, and it shows that COP28 has betrayed the future with an agreement that cannot possibly meet its stated goals.
Coral reefs and low islands are the first victim, but will not the last unless a scientifically sound agreement replaces the current one that died before birth!
Thomas J. F. Goreau, PhD
President, Global Coral Reef Alliance
Chief Scientist, Blue Regeneration SL
President, Biorock Technology Inc.
Technical Advisor, Blue Guardians Programme, SIDS DOCK
37 Pleasant Street, Cambridge, MA 02139
gor...@globalcoral.org
www.globalcoral.org
Skype: tomgoreau
Tel: (1) 617-864-4226 (leave message)
Books:
Geotherapy: Innovative Methods of Soil Fertility Restoration, Carbon Sequestration, and Reversing CO2 Increase
http://www.crcpress.com/product/isbn/9781466595392
Innovative Methods of Marine Ecosystem Restoration
http://www.crcpress.com/product/isbn/9781466557734
Geotherapy: Regenerating ecosystem services to reverse climate change
No one can change the past, everybody can change the future
It’s much later than we think, especially if we don’t think
Those with their heads in the sand will see the light when global warming and sea level rise wash the beach away
“When you run to the rocks, the rocks will be melting, when you run to the sea, the sea will be boiling”, Peter Tosh, Jamaica’s greatest song writer
From:
Tom Goreau <gor...@globalcoral.org>
Date: Thursday, December 14, 2023 at 7:48 AM
To: John Nissen <johnnis...@gmail.com>
Cc: Roger Arnold <silver...@gmail.com>, Planetary Restoration <planetary-...@googlegroups.com>
Subject: Re: Arctic amplification, CDR, and SRM
I dug the book out buried deep in a pile, but I’m sorry to say unfortunately there is little of relevance in the book for your questions.
It covers detailed absorption line spectra of all the radiative gases and focus on issues like pressure broadening effects in rotational-vibrational spectra, radiative scattering from particles and droplets, molecular collision impacts on and “grey” atmosphere models (in which line absorption is independent of wavelength, but which is clearly just a non-physical simplifying assumption, which they resolve by proposing DIFFERENT absorption coefficients for upwelling versus downwelling radiation).
The focus is purely on mathematical modeling of radiative physics in the atmosphere itself, and has no discussion of albedo effects, biology, changes in GHGs, aerosols, very little on atmospheric circulation or climate change other than a brief discussion of runaway greenhouse effects on Venus and the Jovian planets as a function of solar radiation based on work by my former advisor at Caltech.
The discussion on CO2 does not even mention the well-known logistic temperature dependence on concentration caused by absorption line saturation that Roger Arnold refers to below, nor changes in CO2 sources and sinks, nor time lags and feedbacks, and does not touch on EEI at all. Basically it is a mathematical extrapolation exercise based on somewhat unreal simplifying assumptions, so has little useful for your questions about real world responses to perturbed states.
From:
John Nissen <johnnis...@gmail.com>
Date: Wednesday, December 13, 2023 at 2:32 PM
To: Tom Goreau <gor...@globalcoral.org>
Cc: Roger Arnold <silver...@gmail.com>, Planetary Restoration <planetary-...@googlegroups.com>
Subject: Re: Arctic amplification, CDR, and SRM
Hi Tom,
What does this book say about the relationship between temperature and GHG concentration? Is the temperature proportional or the rate of temperature rise proportional to GHG concentration? Will the global mean temperature flat-line at net zero or continue to rise?
Cheers, John
On Wed, Dec 13, 2023 at 1:23 PM Tom Goreau <gor...@globalcoral.org> wrote:
Much of this is covered in:
Atmospheric Radiation: Theoretical Basis 2nd Edition
by R. M. Goody & Y. L. Yung
From: noac-m...@googlegroups.com <noac-m...@googlegroups.com> on behalf of Roger Arnold <silver...@gmail.com>
Date: Wednesday, December 13, 2023 at 5:48 AM
To: John Nissen <johnnis...@gmail.com>
Cc: 'Eelco Rohling' via NOAC Meetings <noac-m...@googlegroups.com>, Planetary Restoration <planetary-...@googlegroups.com>, Peter Wadhams <peterw...@gmail.com>, Albert Kallio <albert...@hotmail.com>, healthy-planet-action-coalition <healthy-planet-...@googlegroups.com>, Hugh.Hunt <he...@cam.ac.uk>, Douglas MacMartin <dgm...@cornell.edu>
Subject: Re: Arctic amplification, CDR, and SRMHi John,
In your point 1, you wrote that the rate of global temperature increase is proportional to GHG concentration. I presume that you meant to say the degree of global temperature increase. That's certainly a function of GHG concentration, although it's a logarithmic function, not a direct proportionality. The rate of global temperature increase is a function of the Earth's radiative energy imbalance.
Those are admittedly nits. However, I don't get the point you're making. Yes, polar amplification is a confirmed phenomenon, and its observed value, as you say, has been ~4x over the period since 1980. And naturally the amplified warming at the poles has led to a decrease in the temperature gradient with latitude. No argument there. But what we're discussing are the physical causes of that amplification. You're suggesting that what I've called the "sleeping bag effect" is "invalid". I don't see how your observation that polar amplification exists has any bearing on why it exists.
Your second point is that "the effect of GHG forcing is essentially uniform across the planet and seasons". Well, yes and no. "GHG forcing", as defined and used by the IPCC, is something I regard as an unnecessary and somewhat artificial abstraction. It obscures the physical processes underlying the greenhouse warming effect, and engenders a lot of confusion. Witness the present case.
GHG forcing is expressed as watts per square meter. But what exactly is that supposed to mean? If one takes it to mean that the effects of GHGs in the atmosphere are equivalent to an increase in the solar constant by the value of the computed GHG forcing, you get one result for the distribution of GHG induced temperature deltas over the surface of the earth. Which result, incidentally, would include zero arctic amplification from radiative heat transfer. It would also imply, as you and Michael contend, that there is no "sleeping bag effect". I.e., that the rate of radiative heat transfer through the atmosphere has no dependence on GHG concentration. But that's crazy, and totally inconsistent with the observed temperature profile for the atmosphere of Venus.
Another way one might interpret the watts / m^2 figure for GHG forcing and the statement that it's "essentially uniform across the planet and seasons" is that the effects of GHGs in the atmosphere are equivalent to bathing the earth in that much additional radiative energy from all directions, rather than just from the direction of the sun. That gives a very different result for the distribution of GHG-induced temperature deltas. That result would show a large value for arctic amplification. It would also show a 4x larger total for the overall GHG heating energy. (The area of a sphere being 4x the area of a disk of the same radius.)
The upshot of all this is that I regard "GHG radiative forcing" as a fictitious concept that yields a value that's arguably useful for quantifying the net warming effect of GHGs over the globe, but is useless for climate modeling. For climate modeling, one really needs to fall back to a rigorous physical model of radiative heat transport. The effect of GHGs present in the atmosphere is to increase the local resistivity to radiative diffusion. The "sleeping bag effect" arises from that model.
If you enter "radiative diffusion" in Google Scholar, it will spit up numerous papers on computational methods for solving the radiative diffusion equations. Many of them are related to spectroscopic analysis and modeling of stars, but the diffusion equations are the same for stellar and planetary atmospheres. That's the reason the astrophysics postdoc I worked for at university had me reading Arrhennius.
Regards,
Roger
On Tue, Dec 12, 2023 at 12:24 PM John Nissen <johnnis...@gmail.com> wrote:
Hi Roger,
1. I don't think your sleeping bag effect is valid. You say:
There's no doubt in my mind that what I'll hereby dub the "sleeping bag effect" -- the tendency of a more insulating greenhouse envelope toward leveling of natural temperature differences between lower and higher latitudes -- does exist. Indeed, how could it not? It would be remarkable if it were found not to be the case. I can't think of any physical mechanism that could account for an invariance of the latitudinal gradient of average temperature as a function of greenhouse gas concentrations.
The explanation for the polar-tropics gradient being a function of GHG concentration (ppm CO2e) is straightforward as I see it. The rate of global temperature increase is proportional to this GHG concentration. Polar temperature is related to global temperature by an amplification factor which has been about x4 since 1980. Thus the temperature gradient across the latitudes between pole and equator has been decreasing as GHG concentrations rise. This is what I think you mean by an invariance.
2. The effect of GHG forcing is essentially uniform across the planet and seasons, as Michael points out.
3. I have been puzzling over a paper which claims that the lapse rate is the largest contribution to Arctic amplification [1]. I could not understand why something to do with the temperature gradient in the atmosphere could provide significant positive feedback. Then I started looking at their underlying assumption for the calculations. They talk about a temperature increment produced by a change in forcing. This is the temperature when equilibrium is reached following that change in forcing. It follows the conventional but incorrect assumption of climate scientists that global temperature is related to emissions (flow) rather than the level of GHGs in the atmosphere (stock). For me, this throws their whole analysis into doubt.
4. The paper does say that the greatest effect of Arctic Amplification is at the end of summer, which would suggest that albedo positive feedback is the main driver (point number 1 on Michael's list) rather than the thinning of ice in winter letting more heat from the ocean reach the surface (point number 2). BTW, I'm not convinced by Michael's argument that this latter effect is a positive feedback: I think it would be negative.
Do the drivers of Arctic amplification, positive and negative, matter? Yes, because these positive and negative feedbacks produce a net forcing which has to be countered by SRM. The positive forcing from albedo loss could be as much as 1.0 W/m2. If there is even greater positive forcing from other factors, even SAI might not manage to counter the net forcing and halt Arctic warming.
Cheers, John
[1] Goosse et al. (Nature Comms, 2018)
Quantifying climate feedbacks in polar regions
On Mon, Dec 11, 2023 at 11:18 PM Roger Arnold <silver...@gmail.com> wrote:
Thanks, John. The point you make about SAI north of 45N is more or less what I had been winding up to say but never quite got to: if we have to resort to SAI to cool the planet -- and I think we do -- it should be selectively targeted toward higher latitudes. If it's uniformly distributed around the globe, it might not cool the arctic sufficiently to avoid thawing permafrost and lowering albedo through summer ice and snow loss. Or, if uniformly distributed in sufficient concentrations to avoid those effects, it will at least cost more for the larger volumes of injected aerosols, and be more likely to have adverse side effects.
As to "arctic amplification", I think we may be running into issues of quantification and use of terminology. There's no doubt in my mind that what I'll hereby dub the "sleeping bag effect" -- the tendency of a more insulating greenhouse envelope toward leveling of natural temperature differences between lower and higher latitudes -- does exist. Indeed, how could it not? It would be remarkable if it were found not to be the case. I can't think of any physical mechanism that could account for an invariance of the latitudinal gradient of average temperature as a function of greenhouse gas concentrations. Since the arctic is starting out as colder than the rest of the planet, reducing the average temperature difference between higher and lower latitudes will naturally cause any given change in the greenhouse envelope to produce a larger change at higher latitudes than at lower latitudes. I.e., polar regions will exhibit higher sensitivity to CO2e gas concentrations. Arrhenius was the first to identify the greenhouse warming potential of CO2, and he also predicted higher sensitivity to CO2 changes at higher latitudes. He's the one who, according to Google, coined the term "arctic amplification" for that higher sensitivity.
Usage of the term could easily have shifted to include the overall result of all processes that contribute to arctic warming. It may well be that albedo feedback is a stronger contributor than the "sleeping bag effect". That kind of makes sense; I know that the value that Arrhenius computed for arctic amplification is substantially less than the value that's been empirically observed. But I'm also not 100% certain that Arrhenius didn't try to model albedo feedback. I've downloaded a copy of his relevant papers, courtesy of Google Scholar, but they don't exactly make for light bedtime reading. As I recall, they weren't light reading even all those years ago, when I was a bright physics student with all brain cells intact.
On Mon, Dec 11, 2023 at 9:45 AM John Nissen <johnnis...@gmail.com> wrote:
Hi Roger,
Earth System operation
One needs to understand the situation in terms of the operation of the Earth System. The central role of Arctic Amplification in the Earth System is to amplify the peak warming signal for the northern mid-high latitude summer. In the past this signal has come from the Milankovitch cycles, and the amplification system has warmed the whole planet such as to create an interglacial period. Global warming from GHGs is mimicking a Milankovitch peak warming signal and is being amplified through the five processes listed by me, Mike and Ye between us.
Why SAI is so promising
SAI injection north of 45N in late spring mimics the Milankovitch peak cooling and has the opposite effect of the peak warming. Crucial to this mimicry is that the aerosol quickly spreads evenly round the planet at the latitude of injection, and then gradually spreads northward, driven by the slow movement of the Brewer-Dobson circulation. Thus you get a blanket cooling effect, which is just what you want to mimic a Milankovitch peak cooling. The associated Arctic amplification of the cooling counters what the Arctic warming has done. For example it will increase the Arctic-tropics temperature gradient, which will re-stabilise the polar jet stream behaviour and reduce the tendency for it to stick and produce stuck weather. Thus with this mid-to-high-latitude SAI we can expect a reduction in weather extremes, among other benefits: such as slowing sea level rise - and avoiding tipping point catastrophe!
Historical precedent
The last peak warming in NH summer was in the early Holocene following the end of the Younger Dryas, 11.7 kya, when the Arctic temperature rose 7-10 degrees C and the ocean switched from having perennial ice to seasonal ice, with little left at the end of summer. Then, probably at the 8.2 kya event with a huge influx of fresh water, the Arctic Ocean switched back to its perennial ice state, which has remained until recently. But now the ocean is again going through the switch to the seasonal ice state, driven by our GHGs mimicry of the Milankovitch peak warming signal.
As regards Albert's point, cost is not an issue: SAI is peanuts in the scheme of things.
Cheers, John
On Mon, Dec 11, 2023 at 3:18 PM Veli Albert Kallio <albert...@hotmail.com> wrote:
The financial difficulties of governments in Europe and US are considerable due to recent Russian expansionism that is demanding urgent action while finances have been left strained after Covid-19 aftermath. There will be very little funds available and cuts to climate change.
China is feared to take advantage together with Iran of current situation as well as Venezuela with new territorial claims and campaigns. US elections are nearing with Trump returning with his climate change denialist agenda and patrons. Things could not get gloomier than now.
From: noac-m...@googlegroups.com <noac-m...@googlegroups.com> on behalf of Roger Arnold <silver...@gmail.com>
Sent: 09 December 2023 21:35
To: via NOAC Meetings <noac-m...@googlegroups.com>
Subject: Arctic amplification, CDR, and SRM
With all the discussion of the need for global cooling -- vs. reliance solely on emissions reduction and CDR -- I'd like to inject a reminder. It's about the nature of arctic amplification. While I'm certainly not opposed to efforts toward global cooling, please remember that the flip side of arctic amplification of global warming is arctic attenuation of global cooling.
It would be quite possible to employ SRM to roll back average global temperatures to, say, 1 C above our preindustrial baseline, and still be left with melting ice sheets and melting permafrost. The rollback in average temperature would not have lifted the threat of runaway CO2 and methane releases from a melting arctic and of catastrophic sea level rise.
The problem is that arctic amplification (or more properly polar amplification, as it applies equally to the antarctic) is a function of a greenhouse atmosphere's resistance to radiative heat loss into space. That goes all the way back to Arrhenius, whose calculations revealed the effect. A more insulating atmosphere reduces the natural difference in average temperatures between lower and higher latitudes. The albedo difference between ice vs open water has its own effects, but that's separate from the polar amplification that Arrhenius predicted.
The best way to understand this may be by an analogy. Imagine you and some friends are camping on a cold night. You all sleep around a campfire, with your heads toward the fire to share its heat equally. Because of the fire, you don't need a thick cold weather sleeping bag to keep your upper body warm. But if you have only a lightweight summer bag, your toes will get cold. If you have a cold weather Himalayan bag, your normal blood circulation will be enough to maintain a nearly uniform temperature, head to toe, inside the bag.
The atmosphere is Earth's "sleeping bag". Greenhouse gases are the source of its "R-value" insulation properties. Historically, it's been a pretty lightweight bag. It has a low R-value, and its "toes" -- the polar regions -- have been cold. But it's had ages to adapt to that, and now depends on it. Then we come along, and commence to pour more greenhouse gasses into the atmosphere. Its effective R-value creeps up, and polar regions begin warming. If the process goes far enough -- as it has on Venus -- the atmosphere becomes so resistive to radiative heat loss that there is virtually no temperature difference from equator to poles.
There's no threat of the Earth becoming a second Venus -- at least not before the oceans have boiled dry -- but the runaway greenhouse potential from melting permafrost is still pretty severe. We have to get Earth a lighter sleeping bag.
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