By Andy May
Christian Freuer has translated this post to German here.
In part one we discussed various estimates of climate sensitivity (ECS, TCR, and observation-based values) and what they mean, especially those reported in the latest IPCC report, AR6. In part 2 we discussed the uncertainty in estimating cloud feedback to surface warming, and cloud feedback’s relationship with ECS. In part 3 we compared the various estimates to one another and discussed the differences between them. In this part we will discuss how Lewis and Curry convert their observation-based estimates of climate sensitivity to AR6-equivalent ECS values. Most conversions of observations to model based ECS are done in a similar way.
Lewis and Curry 2018 (LC18) matched base periods and final periods based upon volcanism records and the detrended Atlantic Multidecadal Oscillation (AMO). Other possible sources of natural variability, including solar variability, were ignored. Using these periods, an estimate of ECS was computed using the equations and values in figure 1 below.
In the table of ECS and TCR estimates, all the ECS estimates are below the AR6 likely lower bound of 2.5°C. Lewis and Curry’s TCR estimates are all below the AR6 likely lower bound of 1.4°C. This is true, even though Lewis and Curry accepted most of the assumptions made by the IPCC in AR6.
In the equations, λ is the climate feedback parameter in W/m2 forcing increase per degree of surface warming. LC18 assumes that λ is constant. LC18 also assume that:
Where ΔR is the radiative response to a positive change in radiative forcing (ΔF) that causes a positive change in the net downward top of the atmosphere (TOA) radiative imbalance (N). The term μR is a random, zero-mean residual term representing internal weather or climate variability that is unrelated to surface temperature changes (ΔT). In essence, R is the response to a change in surface temperature times the feedback parameter plus internal climate variability, which is assumed to be random about zero over the chosen time period. The time periods considered are listed in figure 1.
By assuming that λ is constant over all the chosen time periods, it is then independent of surface temperature, changes in climate state, and changes in radiative forcing (ΔF). Thus:
The above equation derives from the law of conservation of energy and the assumption that internal variability (μR) over the chosen period sums to zero. LC18 (and AR6) then assume that the only outside forcing is due to volcanism and the change in CO2, F2xCO2. This means that ECS can be calculated with the bottom equation in figure 1 if periods are chosen so that volcanism is about the same and the periods fall in the same part of the 60-70-year AMO cycle. These are the same assumptions made by the IPCC.
LC18 uses the detrended AMO, as shown in the upper graph in figure 2. Detrending emphasizes the cyclicity in the AMO, but it removes the long-term trend that is apparent in the raw undetrended data in the lower graph in figure 2.
The longer-term trend affects the base to final period comparisons identified in figure 1. The reason for the underlying secular trend in the AMO is not known but could be due to the Modern Solar Maximum identified in figure 3.
Changes in solar activity are generally small from one solar cycle to the next and from the solar cycle low to the peak. But they are cumulative over time. Extended solar maxima like the Modern Solar Maximum can have a large effect on the climate if they last long enough. The Modern Solar Maximum is the longest period of high solar activity in 600 years (Vinós, 2022, p. 210). Given this, and the apparent trend in the raw AMO, it seems likely that the differences between the LC18 base and final periods are not entirely due to the change in CO2 as assumed by the equations in figure 1.
The AMO trend and the solar activity trend have been up over the past 170 to 300 years, not flat as explicitly assumed in LC18 and AR6. Thus, their ECS and TCR values are maximum values and not estimates of the actual values. This is generally true of almost all observation-based and model-based estimates of ECS and TCR.
Yet nearly all observation-based estimates of ECS and TCR are below the likely lower bound reported in AR6. The problem with the new AR6 climate sensitivity estimates is not just that they are too high, it is also that they are higher than the maximum possible observation-based estimates. This is a point that is not made often enough.
The bibliography can be downloaded here.
An issue with Lewis and Curry’s TCR calculation is that they used HADCRUT for temperature, and that file had been “adjusted”. So I would regard Lewis and Curry’s work as a maximum.
There is no observational climate ‘crisis’. It only exists in climate models that have several basic failings:
There is only one CMIP6 model that ‘agrees’ with UAH temperature history, does not produce a tropical troposphere hotspot, and has an ECS in rough agreement with LC18–1.8C/2xCO2. That is INM CM5. All the rest should be thrown out. Averaging garbage just produces a garbage average.
But it produces the politically correct “result”.
IPCC arbitrarily raised the lower MoE ECS bound from 1.5 degrees C, about right, to 2.0 in 2007, then 2.5, without justification.
A good article on “climate change” and ENSO, from a surprising source:
Good article, thanks.
I can’t find the link but Gabin once said none of the climate models were correct but the average gave the right answer.
#5: Inability to model clouds and other hydrological factors, such as evaporative cooling.
INM-CM5: Evgeny Volodin, Institute for Numerical Mathematics, Russian Academy of Science, Moscow.
😁 I see what you did there LOL!
Earth has been cooling since the February 2016 peak of 2015-16 Super El Niño. NOAA has forecast and is desperately praying for at least La Nada, if not El Niño, conditions later this year, after the rarity of three Las Niñas in a row, following 2019-20 El Niño.
Seven years of cooling under increasing CO2 can be lamely explained away as statistically insignificant. A decade, not so much. Doesn’t mean the Carbonari won’t try. We’ve been here before, with 17 years of The Pause.
Should next Super El Niño, c. 2033, be cooler than last and 1997-98, then the jig should well and truly be up. But probably won’t be.
‘NOAA has forecast and is desperately praying for at least La Nada,..’
Four Las Niñas in a row, or even with La Nada in between, would pretty much falsify all models showing global warming.
Nah…these long pauses are expected. In fact, I’m expecting the current pause to continue for another couple of years at least.
They were not at all expected before The Pause happened. Who predicted the present seven years and counting of cooling?
CMIP5 said that a Monckton Pause with a trailing trend of < 0 C/decade lasting 7 years should occur about 22% of time after 1979. According to BEST it has occurred only about 19% of the time. If the current pause continues for another 2 years then we will have met the expectation from CMIP5.
It might be interesting to note that if we are to include any month that participates in a pause lasting 7 years regards of whether it is leading, trailing, or somewhere in the middle of the pause then the expectation is for nearly 100% of the months to be in such a pause.
Beginning to look a lot like El Niño for Xmas:
But that would blow off a lot of accumulated heat.
Solar Cycle 25 is still likely to be weak, but has shot up more quickly than usual, so ought to peak earlier than normal. Warmer water to be expected as a result.
what is your go to source of available records to support the claims you make. I am interested to review and share with some of my Global Warming Enthusiasts friends..
Mind you, HadCRUT has been heavily stepped upon, but the downtrend is still intact.
More reliable data:
Is it more reliable? I ask because UAH performs at least as much adjustments and infilling as does HadCRUT if not more.
Year / Version / Effect / Description / Citation
Adjustment 1: 1992 : A : unknown effect : simple bias correction : Spencer & Christy 1992
Adjustment 2: 1994 : B : -0.03 C/decade : linear diurnal drift : Christy et al. 1995
Adjustment 3: 1997 : C : +0.03 C/decade : removal of residual annual cycle related to hot target variations : Christy et al. 1998
Adjustment 4: 1998 : D : +0.10 C/decade : orbital decay : Christy et al. 2000
Adjustment 5: 1998 : D : -0.07 C/decade : removal of dependence on time variations of hot target temperature : Christy et al. 2000
Adjustment 6: 2003 : 5.0 : +0.008 C/decade : non-linear diurnal drift : Christy et al. 2003
Adjustment 7: 2004 : 5.1 : -0.004 C/decade : data criteria acceptance : Karl et al. 2006
Adjustment 8: 2005 : 5.2 : +0.035 C/decade : diurnal drift : Spencer et al. 2006
Adjustment 9: 2017 : 6.0 : -0.03 C/decade : new method : Spencer et al. 2017 [open]
That is 0.307 C/decade worth of adjustments jumping from version to version netting out to +0.039 C/decade. And that does not include the adjustment in the inaugural version.
Pay particular attention to their infilling strategy.
15 grids representing 2.5° of longitude each at the equator is 4175 km. Compare this to GISTEMP which only interpolates to a maximum of 1200 km. And GISTEMP does not perform any temporal interpolation.
Those are adjustments justified by instruments and orbits. That’s entirely different from adjustments to maintain a false narrative, such as HadCRU made to bring SSTs in line with its overheated “land station data”, and to adjust for UHI by making the sites hotter rather than cooler. or cooling the past and warming the present, under the guise of “homogenization” and other lame excuses.
UAH homogenizes too. Anyway, I find it odd that you are rationalizing what UAH does and condemning HadCRUT even though UAH applies similar if not arguably more aggressive versions of the same adjustments that HadCRUT does. BTW…the net effect of all adjustments in the land record actually lowers the overall warming trend. Contrast that with UAH where the net effect of all adjustments raises the overall warming trend. So if you’re hang up is based on cooling the past and warming the present then you’ve mixed up preferences then you should be praising HadCRUT and condemning UAH.
A NOAA scientist has just recently issued a paper with revisions to their satellite analysis of temperature. Guess what? It pretty much validates UAH and to a certain extent RSS. Golly Gee!
Mid‐Tropospheric Layer Temperature Record Derived From Satellite Microwave Sounder Observations With Backward Merging Approach – Zou – 2023 – Journal of Geophysical Research: Atmospheres – Wiley Online Library
I think the real temperature profile of the Earth would show the 1880’s, the 1930’s, 1998, and 2016 all on the same horizontal line on the chart. All of them are equally warm, with cooling phases in between.
Today being the hottest temperatures in human history is the BIG LIE perpetrated by climate alarmists.
It was just as warm in the recent past as it is today, which means CO2 has done nothing to affect the Earth’s climate, and has not caused the temperatures to get out of range even though much more CO2 is in the atmosphere now than in the past.
All unmodified, historic, regional surface temperature charts show the temperatures were just as warm in the recent past, as they are today.
The Data Mannipulators and Bastardizers of the current temperature record have caused great harm to humanity by sending them off on a wild goose chase of Net Zero, costing Trillions of dollars. Their scary looking HadCRUT Hockey Stick chart BIG LIE is the cause of this insanity.
Here is a question: The charts below show a U.S. regional chart on the left, and a bogus, bastardized Hockey Stick chart on the right.
All unmodified, historic regional surface temperature charts from all around the world have a similar temperature profile to the U.S. chart profile on the left, where it was just as warm in the Early Twentieth Century as it is today.
So one could assume that since that temperature profile shows all over the world, that this would be the global temperature profile. A benign profile, where CO2 is a minor player since it is no warmer today than it was in the past although there is more CO2 in the air now than there was then. So, CO2 has had no noticeable effect on the temperature profile.
And then we have the computer-generated, bastardized Hockey Stick global “temperature” chart on the right, which show a temperature profile that has been getting hotter and hotter and hotter, decade after decade, and now shows us at the hottest temperatures in human history. A perfect temperature profile if you are pushing the human-caused global warming/climate change scam. And that’s why they mannipulated the temperature profile, to sell this scam.
The Data Mannipulators only had the data from the regional temperature charts to use to put in their computers. Data that does not show a Hockey Stick profile, yet out the other end of the computer comes a Hockey Stick made to order for the Climate Alarmists.
So tell me how one can legitimately take a temperature profile like the one on the left and change it into a completely different temperature profile like the one on the right. That’s what the Data Mannipulators did. That’s how they created the BIG LIE that it is warmer today than any time in the past. It’s not true! The written historic temperature record says it’s not true! These people are lying to us.
It looks like the warming matches expectations pretty well to me.
I wouldn’t hold your breathe waiting for 2033 with expectation that it will be cooler. There is still a positive planetary energy imbalance. It’s risky to even hold your breathe for more than 5 years. With both oceanic heat content and sea surface temperatures in record territory it is all but guaranteed that some of that energy will transfer into the atmosphere in the next several years.
I didn’t say 2033 would necessarily be cooler than now, just that peak next Super El Nino might well be lower than SENs of 1997-98 and 2015-16. IMO, a return to amplitudes akin the SENs of the ’70s and ’80s is at least as likely as higher than the past two. Solar cycles alone argue in favor of weaker Los Ninos.
I also wouldn’t set much store in “record” OHC and SST.
What model predicted global cooling for more than seven years?
I’m not sure why we wouldn’t. The energy is going to disperse eventually.
Most models predict pauses lasting 7 years or more including the CMIP suites. They just don’t say exactly when they will occur in the future due to natural variability.
Anyway, notice that my simple model above is consistent with every pause since 1979. And although you have to be careful with the interpretation the 2.3 coefficient for CO2 is suggestive (though not completely compatible) of a 2xCO2 TCR of 2.3 C. So even at mid-range values of ECS we expect long pauses in the secular warming trend.
What a load of garbage.
You can download the model data from the KNMI Climate Explorer website and verify this for yourself.
“Seven years … can be lamely explained away as statistically insignificant.”
Need logic for what duration can be explained away.
During The Pause, 15 years was suggested, until it extended to 17 years. The Warmunistas were saved by timely Super El Nino of 2015-16, and stillborn El Nino of 2014.
I’d say statistical analysis rather than logic.
Not impossible but unlikely because the warming trend is baked in for a long time. Temperature in the NH will only stabilise or trend down once the permafrost starts advancing south again and that is a century or two away.
The shifts in solar intensity that has caused warming in the NH and cooling in the higher latitudes of the SH started 2,000 years ago.
Good temperature records like UAH have a steady upward trend that is consistent with the much longer upward trend in ocean heat content and sea level rise.
It amazes me that so few people are aware that the current conditions are exactly what is needed for the termination of the current interglacial. Warming ocean surface in the NH producing more atmospheric water at the end of NH summer leading to increasing autumn and winter snowfall. So far only Greenland and Iceland have expanding permanent Ice because of their proximity to ocean but the rest of the land north of 40N will eventually follow.
There is a growing recognition that the climate models fail in predicting the snow cover extent but parameters are being adjusted to get closer to observations:
Once they get the parameters closer to the physical world they will realise that warming ocean surface in the NH is resulting in more snow extent. Then they may realise humans are observing the first recorded termination of an interglacial. Absolutely zero to do with “greenhouse effect” or carbon dioxide. It has happened four times in the last 400k years in the same phase of the precession cycle as now occurring – upswing in NH solar intensity.
IMO, it’s still too early for onset of the next glaciation. We probably can enjoy the rest of the current warm period, endure another little ice age, then bask in one last balmy cycle before the descent into the next big ice age begins.
Might be as much as 3000 years. By then, we may well be able to keep the NH ice sheets from forming.
But secular trends, as warmth since C. AD 1850, contain cyclical countertrends, such as the c. 1945 to 1977 cooling, despite steadily rising CO2.
But I could be wrong. I’m relying on axial tilt as the main Milankovitch cycle. The Holocene has so far been cooler than the Eemian. I’ve suspected it would be shorter, too. However, who knows?
Those who favor other Milankovitch cycles think we might be in for another super interglacial, lasting tens of thousands of years and melting Greenalnd’s Southern Dome.
Termination of at least the last four interglacials all began with rising solar intensity at 40N in the NH as is occurring now. Precession cycle of 23kyr is the sharpest and shortest period in the distinct frequency components in the sea level reconstruction.
All the evidence is clearly indicating increasing snowfall and it is only a matter of time before accumulation is more widespread than what is now being observed on Greenland and Iceland.
More snow requires more atmospheric water, which come from higher ocean surface temperature. This is the strongest indicator of the inevitable termination. The climate models have been getting snow extent wrong but as they are adjusting the parameters to get it closer to measured, the modellers will realise the inevitable – more snowfall and eventually accumulation. They have already come out and said that they predicted more snow but not in the early models. Snow was going to disappear rather than set new records for amount and extent.
”Not impossible but unlikely because the warming trend is baked in for a long time. Temperature in the NH will only stabilise or trend down once the permafrost starts advancing south again and that is a century or two away.”
I hope you’re right but I fear you do not have the all the cards on the table to say that.
The ECS concept, in a clear and distinct way, requires a violation of energy conservation.
That is, the assumption that due to some reduction of OLR we must wait a period of time for the system to “warm” such that the OLR is restored. Of course, during this waiting period energy conservation is violated.
Model a step jump in CO2 – then what happens? OLR is reduced instantaneously, then we wait years for photons to slowly accumulate? it doesn’t make any sense.
Evidently, it seems to me, any trace gas effect must be immediately compensated, such that TCR = ECS.
And obviously, nobody has ever observed this virtual reduction of OLR so it might all be moot.
‘…nobody has ever observed this virtual reduction of OLR…’
Maybe one of the house alarmists will step up to show you the error of your ways. /s
Too many acronyms.
I know it is confusing.
OLR is outgoing longwave radiation
ASR is absorbed shortwave radiation
ECS is equilibrium climate sensitivity
TCR is transient climate response
EEI is Earth energy imbalance
1LOT is 1st law of thermodynamics
The ECS concept is an acceptance of the 1LOT. Remember, ECS occurs when the Earth Energy Imbalance EEI = ASR – OLR is near 0. That is the equilibrium state of the climate system where no net forcing is occurring.
It’s the only thing that makes sense if you accept the 1LOT. ΔOLR < 0 means ΔEEI > 0. Then you have to wait for the Planck response which takes a long time because of the thermal mass of the climate system (mainly ocean) to drive OLR up again to match ASR. And if you factor in feedbacks it can take much longer as OLR will have to play catch up to the increasing ASR.
That’s not possible since EEI > 0.
We don’t expect to. In fact, because of the shortwave feedbacks we expect both OLR and ASR to be increasing right now. The only time we might expect a reduction in OLR is early in the forcing period before the shortwave feedbacks responded. This would likely take us back to at least the early 1900s and probably even into the 1800s. Unfortunately we weren’t taking OLR observations back then.
It is a good effort.
But, the reduced OLR (due to a supposed increase of optical depth) cannot be restored without adding thermal or radiative energy to the system. It is unphysical.
The correct form of energy balance must include the cloud fraction as it relates to the OLR, in addition to its relation to the solar absorbed.
The ad-hoc S(1-albedo) = f(surface flux) function is invalid.
The correct form must relate the cloud fraction to both the solar absorbed and the OLR directly. Albedo cannot be related to OLR in a S(1-albedo) = OLR scheme. The equation is invalid.
Let β = atmospheric condensed matter fraction.
The albedo becomes a function of β; the clear sky OLR is a function of (1-β), and the cloudy sky OLR is also function of β. It is a strict requirement for energy balance.
The effective planetary surface must be defined by the clear sky and variable condensed matter radiating surface. Atmospheric radiation equilibrium is a strict requirement in the dynamic condensing atmosphere. The solar absorbed is coupled to this process in dynamic equilibrium. The EEI can only relate to oceanic uptake.
The 1LOT is as explicit as it gets. EEI = ASR – OLR. A positive imbalance can be restored in 4 different ways. 1) OLR can increase to match ASR. 2) ASR can decrease to match OLR. 3) OLR can increase faster than ASR eventually matching ASR. 4) ASR can decrease faster than OLR eventually matching OLR.
Cloud fraction can modulate both ASR and OLR, but so do many other agents. Anyway, the point is that ECS occurs when EEI approaches 0. That is true regardless of whether clouds are responsible for lowering EEI or not. It is important to point out that EEI = ASR – OLR is the 1LOT.
And the addition of energy to the system is hardly unphysical. It is the inevitability of the 1LOT ΔE = Ein – Eout. When Ein > Eout then ΔE > 0.
ASR – OLR > 0 can only be associated with oceanic heat dynamics as the sun’s energy passes through the system.
EEI cannot be associated with surface flux and optical depth in atmosphere. Balance cannot be restored in the manner described by climatology without violating thermodynamic principles. Radiative equilibrium is a strict constraint in atmosphere. It must be so.
This is for TOA. It includes all upwelling and downwelling radiation sources.
I noted, above, to JCM that he would incur the appearance of one of the house alarmists, and here you are!
Anyway, I’d appreciate it if you could expand on why human activity as far back as the 1800s reduced OLR while today’s much greater level of activity apparently has no such impact.
Also, can you point out where the accumulated photons are? Wijngaarden & Happer (W&H 2023) seem to believe that ‘[i]t is ludicrous to hear about “heat trapped” as photons’.
I think you may have me confused with someone else. I’m not an “alarmist” based on most definitions though it may depend on your specific definition.
Anyway, OLR is expected to increase with GHG warming due to shortwave feedbacks. The retained energy is stored in the land, cryosphere, hydrosphere, and atmosphere. See Donohoe et al. 2014 for explanation of how shortwave feedbacks cause OLR to increase. See Schuckmann et al. 2020 for breakdown of where the accumulated energy is dispatched.
Considering radiative equilibrium must be a strict requirement in atmosphere, the entire thing has been turned upside down.
The atmosphere is the semi transparent fluid dynamic condensing layer between ocean and space. It is quite free, you know. The atmospheric base and top are in fixed radiative proportion, in the order of 3/2. 1 unit of atmospheric heat at the base will be matched by 2/3d unit at the top.
It’s constantly stirring around and condensing. It has reached its hydrodynamic equilibrium state and nothing will change that. It doesn’t mean it can’t warm or cool, of course. It means its radiative greenhouse factor is fixed to 1/3. Greenhouse has nothing to do with climate change, but it is critical to understanding the earth system in relation to the moon, for example.
Anomalous SW absorption into ocean is a far simpler and physical explanation for EEI. The atmosphere, always being in radiative equilibrium, will take on characteristic changes to oceanic input and export conditions. The anomalous Earth System Heat trapping cannot be due to an atmospheric LW greenhouse disequilibrium mechanism. Such a notion is plainly unphysical.
The atmosphere is in strict radiative equilibrium. However, it is that layer between ocean and space.
The atmospheric radiation enthusiasts impose something like 1% atmospheric disequilibrium to force 90% of heat into ocean by longer waves, or something like that. In fact, it is the other way around. The atmosphere cannot be in an disequilibrium. It takes on oceanic characteristics.
We see the EEI is least when ocean releases heat during El Nino. The atmosphere is warmest when EEI is least. So, we know it is the ocean governing EEI. Atmospheric long wave disequilibrium cannot impose an EEI, because so such mechanism is possible.
Rest assured, climate change is certainly real, And there is no reason humanity cannot disrupt the global average cloud fraction and global circulation by profound ecosystem change. It is easy to understand how anomalous Shorter Waves can be penetrating into ocean, resulting in an EEI.
There are numerous confounding co-variables which climatology has chosen to ignore. However, in strict respect of thermodynamics the atmosphere will not and cannot maintain a radiative disequilibrium.
are you basically saying –
“we don’t know what we don’t know”?
(if so, I agree 100%)
Hello Mr. That is always true. It is also related to an outright refusal to see, think, and discuss. Cognitive biases and heuristics in climatological resources created as a consequence of UNFCC/IPCC problem definitions. An entire field reduced to creating evidence for this cause. Exploratory research required to understand the exact nature of the problem is frowned upon.
Let’s get real. If a minor fraction of today’s emissions supposedly suppressed OLR back in ye olden days, then it stands to reason that today’s enhanced emissions would still do likewise. That kind of consistency is the hallmark of a real physical process, as opposed to the special pleading or magical thinking needed to explain the ‘counterintuitive’ (Donohoe et al’s word, not mine) virtual physical processes taking place in the GCMs.
I think you and the rest of the alarmists need to come to grips with the simple fact that if the preponderance of the feedbacks affecting the Earth’s climate were actually ‘positive’, we wouldn’t be here today.
That would only be true if 1) there are no shortwave feedbacks and 2) the EEI is increasing.
Not only are shortwave feedbacks are not magic, but the CERES data that is almost universally accepted on WUWT says it is happening. Counterintuitive does not mean magic. It just means that the priors some people assume aren’t true.
It’s an absurd hypothesis. Despite these feedbacks we’re all still here. That should falsify your hypothesis.
‘It’s an absurd hypothesis. Despite these feedbacks we’re all still here. That should falsify your hypothesis.’
Practitioners of CliSci are the only ‘scientists’ I’m aware of who consistently abuse the scientific method by improperly reversing the correct formulation of the null hypothesis.
But I wanted to get back to your narrative re. the initial CO2 ‘forcing’ vs, the climate’s ‘response’ on the way to ECS. If I understand correctly, you’re saying that:
1) Increasing CO2 causes OLR to decrease from OLR_0 to OLR_t;
2) Decreasing OLR causes ASR to increase from ASR_0 (= OLR_0) to ASR_t
3) Increasing ASR causes OLR to first rapidly increase from OLR_t to OLR_0, and then eventually to OLR_T as ASR_t increases to ASR_T (= OLR_T).
Question: Is there any physical evidence for any of this, or is it just a manifestation of the same models that demonstrably, not only run way too hot, but also fail to agree among themselves or with past climatic conditions?
I don’t know what you mean here. We were talking about your hypothesis that a preponderance of positive necessarily results in the non-existence of humans.
If I’m understanding you correctly then yes…mostly anyway. You used the word “rapid” in point 3 though. Note that Donohoe et al. 2014 show that the expectation is that the drop from OLR_0 to OLR_t takes about 20 years with the original OLR being restored (OLR_t to OLR_0) after 80 years under a 1% CO2 growth scenario. It’s not what I would I call rapid.
Yes. The CERES data, which is widely accepted on WUWT, shows ASR and OLR both increasing inline with expectations.
‘I don’t know what you mean here. We were talking about your hypothesis that a preponderance of positive necessarily results in the non-existence of humans.’
Given that the Earth’s climate has favored the existence of life since at least the end of the Cambrian, my null hypothesis would simply state that the preponderance of the Earth’s climate feedbacks must be negative.
To refute this, you would not only need to show compelling evidence that the feedbacks are positive, but also to demonstrate why major warming or cooling trends in the past didn’t cause life on Earth to become untenable.
‘The CERES data, which is widely accepted on WUWT, shows ASR and OLR both increasing inline with expectations.’
Any increase in ASR, for whatever reason, will cause an increase in OLR. That’s a trivial result. What I’m asking for is physical evidence, not GCM output, that mankind’s emissions of CO2 have caused a decline in OLR and a subsequent rise in ASR.
A lot of feedbacks are positive. But being positive does not mean unbounded. Most (all?) of the feedbacks have braking and clamping effects. For example, water vapor is both braked and clamped because it is a condensing gas. CO2 is braked and clamped because the carbon cycle is partitioned by the speed of the processes and because carbon stock is finite. And the radiative response in general is clamped by the Simpson-Nakajima limit. What that means is that a runaway greenhouse effect is not possible on Earth.
PS – I don’t know who’s downvoting your comments, most of which I find educational, at a minimum. As a rule, I limit myself to upvoting comments that I find particularly useful and to commenting when I have questions and/or think I have something to add.
The downvotes don’t bother me. I don’t pay any attention to the votes on my posts. And as I’ve said before, like you, I only ever upvote. That often includes people I disagree with. I have never downvoted anyone on here.
“”higher than the maximum possible””
Worse than they thought…
Regarding in the Conclusions, “The AMO trend and the solar activity trend have been up over the past 170 to 300 years, not flat as explicitly assumed in LC18 and AR6. Thus, their ECS and TCR values are maximum values and not estimates of the actual values.”
However, I noticed immediately above Figure 2: “LC18 uses the detrended AMO, as shown in the upper graph in figure 2.”
As for solar activity: Figure 3 shows the Modern Maximum having a primary peak in the 1950s and a secondary peak in the early 1980s, and global temperature increase accelerated rather than decellerated after a roughly 1970 peak of few-decades-smoothed solar activity. Global temperature continued to increase after solar activity dipped to a roughly 175 year low from ~2009 to now according to the red and blue bars in Figure 3. And, global temperature rate of change from about 1915 to about 1975 has noticeably good negative correlation with solar activity. So, I think solar variation has negligible effect on global temperature in time scales used by Lewis & Curry, even though it seems to have significant effect on multicentury time scale, so I think climate sensitivity figures by Lewis & Curry are not significantly contaminated by ignoring solar variation.
Why do you think that solar variability has an immediate response? An increase in solar activity is quite small, only a long period of time, at an elevated level has an impact on climate. The oceans, especially the tropical oceans, absorb most of the sunlight that hits them, it takes a while for that energy to work its way through the climate system.
The Sun is more of a trigger than a cause. Most of the energy to change the climate is already in the climate system. The fall in solar activity after 1990 is only now being felt, 30 years later. Remember, the AMO has a 60-70-year period.
Regarding “The reason for the underlying secular trend in the AMO is not known but could be due to the Modern Solar Maximum identified in figure 3.” The AMO index is defined as SST as averaged over a defined region of the North Atlantic, with the latitude part of this being between the equator and 60 degrees N. Manmade global warming from manmade increase of greenhouse gases is looking like the main reason for the trend (that needs to be removed) being upwards during the decades after the Modern Maximum (of solar activity) peaked out, and being upwards through the bar graph part of Figure 3 being non-positive for over 2 decades and close to a 150-year low since the start of the bar that starts ~2009.
Actually, it is the equator to 70 degrees. The AMO began to flatten in 2005, just as the Modern Solar Maximum ended. It will begin to decline sometime in the next two decades. There is a significant lag between solar activity and the AMO and other oscillations. There is also a lag between the oscillations. See the “Stadium Wave.”
The stadium wave | Climate Etc. (judithcurry.com)
It looks like there is more than one AMO index. I saw North Atlantic from the equator to 60N in:
Another source says equator to 60N, 0 to 80W and detrended:
Another source says equator to 60N 0 to 80W, minus temp. of the world’s oceans between 60N and 60S:
This a subject I’m very familiar with. The original article naming the AMO was Richard Kerr’s Science article in 2000, but he was vague about the area boundaries. The AMO was then properly defined by Stephen Gray, et al. in GRL in 2004. He places the boundaries at 0-70 degrees for the North Atlantic. But, like everything in climate science, people arbitrarily change the definitions all the time. It is a classic pseudoscience.
A tree‐ring based reconstruction of the Atlantic Multidecadal Oscillation since 1567 A.D. – Gray – 2004 – Geophysical Research Letters – Wiley Online Library
Forgive my ignorance of the subject, so let me make a stupid comment. Why is it that it’s assumed by everyone (?) that ECS is a number and not a variable with many elements? That is, perhaps, ECS changes depending on the level of CO2 and maybe depends also on the level of other gasses, on the intensity of sunlight, cosmic rays, whatever. So, maybe it’s a complex formula, not just a single number.
ECS is a ceteris perabus metric for 2xCO2. The actual amount of change in the global average temperature is modulated by the net effect of all agents acting together.
The effects of CO2 look to be variable. There appears to be a warming effect starting at very low concentrations which falls to zero when saturation is reached (around 100-200 ppm). This is due to the dual nature of CO2 effects.
You initially get a linear increase in IR absorption which then becomes logarithmic. The evaporative cooling effect is also logarithmic. As a result, once concentrations are above 200 ppm the two effects balance out.
Since climate sensitivity would be the combination of these two effects, it would start at a higher value and eventually become near zero. As far as Earth is concerned, it has always been essentially zero.
Note that climate science only recognizes the warming effect. The cooling effect has been pointed out (see Gray 2012), but climate science treats it as a positive feedback by ignoring the increase in convective currents which must occur.
Climate changes due to multiple factors including those you list, and internal variability; which is best examined though ocean oscillations like ENSO and the AMO. Don’t fall into the IPCC semantic trap that tries to equate ECS with climate change, they are not the same thing.
ECS is not a real number, nor is it scientific. It is a model construction based on a scenario where CO2 doubles instantaneously, which is an impossibility. After the doubling, the hypothesized warming due to the doubling, is somehow allowed to work its way through the system over the next several thousand years with nothing else affecting the climate change. That can never happen either, but if it does the ultimate warming would be ECS.
It is not a falsifiable number; thus, it is not a proper scientific hypothesis.
Of course it is real and scientific. If you double atmospheric CO2 concentration the temperature is going to change. It’s no different than examining what would happen if a large volcanic eruption were to happen, or if a solar grand minimum/maximum occurred, or if the Earth were in a different phase of the Milankovitch cycles, or any of the numerous others factors known to effect the climate were to change. And we’re running the experiment right now just like was done during the PETM and other periods in Earth’s past. So far we are about 55% of our way to ECS for 3.7 W/m2 of forcing (the equivalent of 2xCO2). If the experiment is allowed to continue we can falsify the ECS hypothesis listed in this article. It may not be easy or without complications, but it can be done.
But if something can’t physically be done (in this case, INSTANTANEOUSLY doubling CO2 in the current atmosphere), what is the purpose of modeling any assumed effects from such an impossible action?
(other than ongoing employment for climate modelers of course)
The pulse does not have to be instantaneous for there to be an ECS.
If it is not instantaneous, it’s TCR.
That’s not what TCR means. See IPCC AR6 WG1 Annex VII pg. 2223 for details.
Anything that is not testable or falsifiable is not a scientific hypothesis. To quote the famous Karl Popper’s examples of pseudoscience, he observed on page 35 of his famous book:
“A Marxist could not open a newspaper without finding on every page, confirming evidence” for the theory.
Freud’s theories were the same; every clinical case confirmed his ideas. A hypothesis that is not refutable by any conceivable event is not scientific.”
The book can be seen here:
(PDF) Karl Popper: Conjectures and Refutations | Danny Frederick – Academia.edu
Any estimate of ECS is not testable or falsifiable, as such it is pseudoscience, like astrology, and not science. TCR is probably falsifiable and so are observation-based estimates of climate sensitivity, but ECS is not.
That the prompt, no feedback effect of doubling CO2 is 1.1 to 1.2 degrees C of warming might be testable. Not on an atmosphere wide scale, but with possibly meaningful experiment.
Of course it is testable. For example, if the hypothesis is that the ECS of 2xCO2 is > 1 C then we let the experiment continue until RF – EEI = 3.7 W/m2 and observe whether the temperature increased by at least 1 C. Alternatively you can let the experiment continue until the temperature increased by 1 C and observing whether RF – EEI < 3.7 W/m2.
We are not testing the direct effect of CO2, but CO2 + feedbacks + total Earth inertia. Your described experiment can only test TCR at most, not ECS. Your experiment is perfect for testing classical observation-based estimates of climate sensitivity.
Yes. I know what ECS is. That is a test of it. Specifically it is designed to falsify the lower bound of a range that is too low.
An experiment such as you describe would have to be at least 1,000 years long (Sherwood, et al.). By then would anyone care? We could be entering the next glacial period by then.
Unless otherwise noted it is assumed ECS is for fast feedbacks lasting no more than 100-200 years. So all we have to do is wait for either 1 C to occur or 100-200 years. And it should be obvious how you would alter the test if you didn’t want to wait for 1 C or 100-200 years.
Sorry, you’re completely off the rails here. First, it is stated that it is not possible to instantaneously double the concentration of CO2 in the atmosphere. If that is an impossibility, the an “ECS” is not real and most certainly is not scientific.
As pointed out above, by ‘Richard M’, the effect (if any to begin with) past a certain concentration is logarithmic. We’re well past CO2 having any measurable “warming” effect on climate. Need proof? Fine. Just look up the Hirnantian (last Epoch of the Ordovician). CO2 concentrations are accepted as having been about ten times today’s value (Berner & Kothavala), yet we have clear and compelling evidence of an ice age having taken place, approximately two million years long, or longer. It ended in the early Silurian.
And, dozens of posters here and other places have pointed out that in the ice core data are definitive: CO2 FOLLOWS temperature changes. Even the IPCC is forced to admit that. Talk about cognitive dissonance! They admit they’re wrong, but insist they’re right!
If you haven’t seen it, an article was recently posted on-line, called, “What is a Democrat?” Well worth a read. Describes a lot of ‘climate scientists’ as well … … …
CO2 does not have to instantaneously double for it to have an ECS. In fact, the pulse duration is mostly irrelevant in regards to the final equilibrium state.
Using the canonical 5.35 * ln(ΔCO2) formula from Myhre et al. 1998 we see that 560/280 has the same effect as 1120/560 or 280/140.
Indeed. According to GEOCARB it was about 16x the 1950 level or about 5000 ppm. That is an RF of about 5.35 * ln(16) = +14.8 W/m2. During the same time the Sun was 4% dimmer which is an RF of about (1-0.04) * 240 = -9.6 W/m2. And Gondwana stretched from the south pole past the equator making for a very expansive ice anchor with an explosion of biological mass and diversity. There were undoubtedly many other factors that set the stage for an ice age during the period. The point…CO2 is not the only thing that modulates EEI, the global average temperature, and ultimately the climate.
Yep. And that is expected. The reason is because in additional CO2 catalyzing temperature changes the reverse also happens where temperature changes catalyzes CO2 changes. In other words, CO2 can both lead or lag the temperature depending on which one changed first. And since the temperature was being forced by something else initially during the glacial cycles it is expected that CO2 would follow temperature first and then further force the change second. Examples of why it is leading the temperature change are the PETM, other ETMx events, and the contemporary period.
It sounds political. I hate politics with a passion. I’ll pass.
If CO2 does not instantaneously double, then you are talking about TCR, which AR6 claims is only half of ECS, so it does matter.
TCR is the moment 2xCO2 occurs. ECS is the moment when equilibrium occurs. Typically TCR is in reference to a pulse of 1% annual growth in concentration. That’s the scenario the IPCC considers anyway. With the understanding of what TCR is it should be obvious that TCR for instantaneous pulse would always be 0 regardless of the ECS.
As above, the definition of ECS is an instantaneous doubling, so there cannot be an “ECS”. It is a complete fabrication of climate models.
Excellent statement here: “According to GEOCARB it was about 16x the 1950 level or about 5000 ppm.”
Then you go into the fabricated RF (no such thing) discussion, and the ‘dimmer’ sun (if the sun was that much dimmer, say, in the Ediacaran, why was much of the Ediacaran warm? Not CO2). The Silurian was also warm, with less CO2 than during the late Ordovician. And that same ‘faint sun’.
Then you finally get to the heart of the matter: “The point…CO2 is not the only thing that modulates EEI, the global average temperature, and ultimately the climate.”
Precisely. Thanks for joining the club: CO2 has essentially zero impact on climate, temperature, or much of anything else. So almost everything the IPCC says is wrong. They got the n ln (C/Co) part right, but I’ve seen too many papers that argue that n is very likely less than one (one of the best argued for 0.98, but I’ve seen a couple stating that it is potentially 0.1 or 0.2 … ). n does not equal 5.35, or any other ‘derived’ value that the IPCC uses in the various forms of the equations. They got the “ln” part right, and the rest of it wrong.
Nice word salad on the EPICA results. I like the part that sometimes CO2 causes warming, and sometimes it causes cooling. Hope you can square that with the times/places on EPICA that CO2 is going UP while temperature is going down.
See Mr. May’s comment also on ECS. It would be nice if you could maintain some consistency on what it is you’re discussing. If it is an imaginary “ECS”, then stick to the definition, please.
And if you really ‘hate politics’ that much, you shouldn’t be in a discussion of ‘climate science’. Sounds to me like you really do like politics a lot. I think your real fear is of finding out the truth about yourself; reflection is a good thing, in many cases.
There is no requirement that the pulse of CO2 be instantaneous. See IPCC AR6 WGI Annex VII. In fact, unless specifically stated the CO2 pulse is assumed to be 1% annual growth of concentration.
It’s an application of the 1st law of thermodynamics (1LOT). That is about as real as it gets.
Just like CO2 isn’t the only thing modulating EEI the Sun is not an agent that acts in isolation either. There are many other players. It is the net effect of all actors that determines the EEI.
Actually 5.35 may be a bit low. I’ve not seen any estimates even remotely close to 1 that have been tested in the real world like the say that from the RRTM which has 2xCO2 RF closer to 4 W/m2.
CO2 does lead to cooling when it declines if that is what you’re talking about. Anyway, there’s not much to square up here. Remember…1) CO2 is not the only thing modulating the climate and 2) CO2’s response to temperature is very slow (on the order of hundreds of years) so when the temperature is forced to change we don’t expect an immediate response in CO2 concentration.
I have seen his comments. I’m not sure what the concern is with consistency. If there is something specific you want me to clarify let me know. And the definition I’m using for ECS is the one in widespread use. That is it is the equilibrium state in surface temperature after CO2 has doubled.
Then, I take it you dispute that we’re well onto the asymptotic portion of the ln x curve; if a ‘doubling’ of CO2 concentration is going to cause a change in temperature, you accept the IPCC value (or, you believe the 5.35 is ‘low’ and should be higher), correct?
At your ‘rate’ of 1%, it takes almost 70 years for a ‘doubling’ to take place; note Mr. May says that this would not be an ECS. The values are nothing more than PlayStation climatology. So much can (and does) happen in the span of 70 years that trying separate signal from noise would be an exercise in futility.
You admitted that sixteen times CO2 concentration did not prevent an ice age from happening, due to CO2’s effect (if any) being overwhelmed by other factors. “CO2 is not the only thing that modulates [Earth energy imbalance], the global average (sic) temperature, and ultimately the climate.” End of story. CO2 basically has nothing to do with average global temperature, temperature change, or any ‘changing’ climate.
Thanks for coming on board,
I don’t know. It depends on what you call the asymptotic part. If it is d/dx 5.35*ln(x) < 1 then that won’t occur until CO2 hits 1400 ppm.
5.35 * ln(ΔCO2) comes from Myhre et al. 1998. It’s just an approximation formula from the outputs of the BBM, NBM, LBM, etc. I’m just saying more modern radiative transfer schemes like the RRTM, which is tested countless times every single day, would suggest a slightly higher coefficient if we used the same approximation formula.
It’s not my rate. But yes, 1.01 ^ 70 = 2.
Correct. With a 1% growth scenario 70 years would mark the point of the TCR.
Of course it does. It changes the energy balance of the climate system. And since the climate system has a finite specific heat capacity it must warm in response to an accumulation of energy.
Sorry you missed the point. At “16X” the 1950 CO2 concentration, it’s fairly strong evidence that the figure of 5.35 is much too high. Those who have refined the calculation(s) have demonstrated that the coefficient has a very high probability of being less than one, and from what the Hirnantian tells us, it’s strong evidence that the coefficient is just a small fraction of one (say, 0.1 or 0.2).
I stated, “CO2 basically has nothing to do with average global temperature, temperature change, or any ‘changing’ climate.”
You stated, “Of course it does. It changes the energy balance of the climate system.” So, in the Ordovician, for some strange reason, CO2 was changing the energy balance so that cooling took place, and a lot of it, from what the geological record tells us.
Apparently you do not understand the concept of an ‘asymptote’. As was stated above, once one has hit a CO2 atmospheric concentration above (approximately) 200 ppm (we’re north of 420 ppm in 2023), the diminishing, asymptotic ‘warming’ effect of CO2 becomes unmeasurable. And, since you’ve dodged it in the post above, you clearly stated that other parameters affect global climate: “CO2 is not the only thing that modulates [Earth energy imbalance], the global average (sic) temperature, and ultimately the climate.” If “16X” the 1950 concentration failed to cause a “thermageddon”, then why should anyone be concerned with 0.04% of the atmosphere being CO2? Do you now disavow your statement, or do you stand by it? If you stand by it, then you have admitted that CO2 is nothing more than a bit player in the whole of Earth climate.
Even better, from my perspective, is the Cryogenian. According to the best estimates from Geologic Time Scale (2004, 2012, 2016, and 2020) this ice age took place during times of CO2 concentrations being measured in percents; the low end is about 4%, the high end being about 13%. And please refrain from using the ‘faint sun’ argument: much of the preceding Proterozoic was quite pleasant (from a ‘temperature’ perspective), as was the later Ediacaran. The reason CO2 had nothing to do with keeping things warm during a ‘faint sun’ era is due to that asymptotic nature of the warming effect. CO2 does all it might do in the first 200 ppm, give-or-take, and after that, it’s just a spectator. By far and away, water vapor is the dominant “greenhouse” gas in the Earth’s atmosphere, being roughly 10 – 25 times more abundant than CO2, and being radiatively active across a much larger portion of the thermal IR spectrum than CO2. Do you dispute that water vapor is the dominant “greenhouse gas” in the Earth’s atmosphere?
It is certainly possible that the fit to the true RF curve using the 5.35 ln(ΔCO2) approximation isn’t as good at higher concentration levels as it is a lower concentration levels. But no there is no expectation that it should be. It is but a simple approximation for back-of-the-envelope calculations. If you want a more accurate estimate you’ll have to do the full integration using the NBM, BBM, and LBM like what Myhre et al. 1998 did to get the approximation formula.
That can’t be right. 0.2 * ln(16) = 0.55 W/m2 yet 5.35 * ln(2) = 3.7 W/m2. In other words, you’re saying that 16xCO2 has less RF than 2xCO2.
Can you provide a reference to “those who have refined the calculations”? Do they test their radiative transfer model trillions of times a day like RRTM?
The asymptote of 5.35 * ln(ΔCO2) is around 45 W/m2. But you didn’t mention the asymptote. You mentioned the “asymptotic portion” of the curve. I don’t know what portion you are speaking of. Is it when the first derivative is less than 1? Or are you thinking of something else?
5.35 * ln(420/280) = 2.2 W/m2.
5.35 * ln(560/420) = 1.5 W/m2.
5.35 * ln(560/280) = 3.7 W/m2
Notice that an increase from 420 to 560 ppm is expected to produce an RF of +1.5 W.m2 which is only slightly less than for increase from 280 to 420 ppm. I’m not sure what the concern is here.
I think there may be some confusion here. Just because 16xCO2 isn’t always associated with high temperatures does not mean that 16xCO2 does not have a higher RF as compared to 2xCO2, 4xCO2, or 8xCO2. Remember, CO2 is not the only thing modulating the EEI. It is the net effect of all agents acting together that determines the final EEI and ultimately how the climate responds.
And remember, 500 MYA the solar RF was 0.042 * 240 = -10.1 W/m2 which offsets a good portion of the 16xCO2 RF of 5.35 * ln(16) = +14.8 W/m2. If you think the 5.35 coefficient is too large then understand that the lower you drop it the more the solar RF offsets the CO2 RF.
I stand by my statement. I won’t however, defend your statement.
You don’t want me to consider the Sun?
5.35 * ln(420/280) = 2.2 W/m2.
5.35 * ln(40000/420) = 24 W/m2.
At 40000 ppm the RF relative to today is 10x higher than the RF of 420 ppm relative to preindustrial.
No. I don’t dispute that. I also don’t dispute that it is a condensing gas that is in equilibrium with the temperature and thus cannot catalyze temperature changes on its own.
First, nowhere did I ever mention that water vapor can ‘catalyze’ temperature change. I only stated that it is the most powerful ‘greenhouse gas’ in the Earths’ atmosphere. I will thank you to not put words into my mouth. Either do one of those ‘block quotes’ that you do, showing me where I stated that water vapor can ‘catalyze’ a climate change, or issue an apology for claiming I made a statement that I did not make. Under no circumstances have I ever thought that water vapor was an agent of climate change. For all practical purposes, WV concentration(s) have been fairly consistent for the majority of the Holocene. Note that Alley’s (2000) presentation shows temperatures changing (randomly), at the same time that (the IPCC claims) CO2 remained relatively constant (and you’re using their figure of 280 ppm as the ‘pre-industrial’ value).
Water Vapor is at least an order of magnitude more powerful than CO2 ever thought of being, and it is likely two orders. It is more abundant, and absorbs across a larger portion of the thermal IR spectrum; anything that CO2 might be doing, water vapor does overwhelmingly.
Second, I’ve tried to show you that the geologic record says that you are 100% wrong in your thinking. You continue to use a mythical (model-derived) constant, citing mythical ‘radiative forcing’. I will await your refutation of the clear geologic history of the Earth that tells us that CO2 has little-to-no impact on Earth climate.
Third, it is empirical that CO2’s “warming” goes minuscule past 200 ppm (as shown above). Showing patronizing calculations with incorrect constants is quite meaningless. If you require me to do a calculation, then please state so; I’m quite capable.
You have surprised me — — I would think that you can locate any number of papers on that constant. I had little difficulty.
Most of us grow out of our infantile, irrational fears of imaginary ‘boogey-men’. It is interesting to me that you are unable to show any maturation and leave such unfounded fears behind you.
If you are unfamiliar with Einstein’s quote (regarding his newly-published theories), note that he said, “No amount of experimentation can ever prove me right. A single experiment can prove me wrong.”
So let’s see what a small portion of the geological record shows us:
Hypothesis: CO2 affects temperature (you may have a variation on this; if that is the case, then please state it).
Cryogenian: CO2 atmospheric content in the ‘percent’ range of concentration; Earth was in a major global ice age (the oft-called “Snowball Earth”; with that much CO2 in the atmosphere, ‘Snowball’ should have been well nigh impossible). Hypothesis falsified. [Do take note that it was ‘warm’ in the Tonian, and the Ediacaran, with very similar CO2 concentrations, and that same ‘faint sun’ you’re so fond of]
Late Ordovician, Hirnantian Epoch: “16X” the 1950 concentration of CO2 in the atmosphere, major glaciation; Early Silurian, CO2 concentration is 8X – 10X the 1950 concentration, and the global climate is warmer than today. Hypothesis falsified.
Holocene, Alley (2000) graph [which, if I’m not mistaken, is available on the “Reference Pages”]; temperature changes both directions, and for the most part, it is warmer than it is today, and (the IPCC says) the CO2 concentration was roughly constant. Hypothesis falsified.
So, if you accept Einstein’s statement, a single instance of falsification should cause one to reject that hypothesis. There is a wealth of learning you could do, just here on WUWT, but you must avail yourself of it. That’s another sign of immaturity: rejection of any contradictory information, without studying it. Again, you should delve into that article, “What is a Democrat?”. It is highly instructive, and please do not tell me that politics disagrees with you. “Climate Science”, such as it is, is nothing but politics; it left Science behind, somewhere right about 1988, and hasn’t looked back.
I know. I mentioned it. And I did so to make it clear that although water vapor is a GHG it cannot catalyze temperature changes because it is a condensing gas. That sets it distinctly apart of CO2.
I’m not saying that I think you made a statement contrary to H2O being a condensing gas and not catalyzing temperature changes. I’m making the statement. But I’m still going to apologize nonetheless. I’m apologizing for making you feel that way. It is never my intent to make some feel personally slighted. I’ll be more careful in the future.
It a part of climate change. It is feedback agent not unlike clouds and other albedo changing agents.
H2O does not fully cover the spectral band that CO2 does. H2O cannot do what CO2 is doing.
It’s the 1st law of thermodynamics. That is not mythical. It is as real as it gets.
I’m not going to refute the evidence if that is what you’re asking. The geologic history of Earth tells us that CO2 must have some effect and likely a very large effect. It is an essential component in explaining the faint young Sun problem afterall.
It’s actually the opposite. Given the faint young Sun it is actually difficult to explain why the Earth wasn’t always snowballed.
I know. It’s a testament to the fact that neither CO2 nor the Sun act in isolation.
Yes. I work with the Alley data a lot. It can be found here. Yes. the temperature goes up and down. Note that the Alley data is only from central Greenland and up to about 1850. The last 170 years of warming in Greenland are not available in his dataset. It has warmed significantly in the last 170 years. There may have been a period in the early Holocene where it was warmer than today, but for the most part it was cooler.
Yes. 5.35 * ln(8) = + 11 W/m2. That is a lot forcing relative to today. That more than offsets the faint Sun. All it would take is a slight change in albedo to send the Earth into a hothouse.
Absolutely. And the more I learn the more I realize how little I know.
Sorry. Politics disagrees with me. I’m not saying that as a personal attack against you. I genuinely do not like politics.
And in effort to make my intentions clear I want you to know that my responses are in good faith. When I say something I’m not necessarily saying that you disagree. What I’m doing is stating, to the best of my ability, what science knows about these topics. Also, understand that the information isn’t mine. It came from people far smarter than I.
We must be cognizant of the fact that the IPCC changes its definition of ECS often, even as it tries to equate it to climate change. They admit these frequent changes in AR6, Sherwood also mentions them.
This is one of Karl Popper’s warning signs of pseudoscience.
Karl Popper, Conjectures and Refutations, p. 37.
(99+) Conjectures and Refutations – Karl R. Popper | brade gomez – Academia.edu
Karl Popper didn’t necessarily reject theses that theoretically couldn’t be “falsified”. Rather, as with Darwinism, he believed that we should act on “the most successful explanation of the relevant facts”. I.e., AGW.
I’ve not seen any significant changes in the definition of ECS. It has always been the equilibrium state after 2xCO2.
The only real question I’ve seen is how close to equilibrium do we mandate. Do we wait for the fast feedbacks only (100-200 years) and call it good? Or do we wait for the slow feedbacks to play out (10000 years or more)? Unless otherwise noted ECS is almost always in reference to the fast feedbacks (100-200 years).
‘I like the part that sometimes CO2 causes warming, and sometimes it causes cooling.’
And more often it does nothing. It’s really quite versatile!
Yes and no.
From page 933:
Fill in the time. The models do it all at once.
From Sherwood, et al.:
None of those quotes say anything about ECS being restricted to instantaneous pulses. It is an applicable metric for any pulse duration whether it be instantaneous, 1% growth, or something else.
Section 184.108.40.206, “ECS Estimated Using Process-based Assessments of Forcing and Feedbacks”, page 993 :
Attached at the end of this post is a screenshot of “Box 7.1, Figure 1”, which can be found on page 932 of the AR6 WG-I assessment report.
Note especially the “title” above the left-hand panel :
“(a) Definitions based on idealised 2xCO2 response”
As the caption underneath that figure clearly states :
When defining ECS (and ERF), the IPCC decided to start with an instantaneous EEI of 4 W/m² … i.e. the “energy imbalance” resulting from an “idealised 2xCO2” input step after the model has been “spun up”, with atmospheric CO2 concentrations then being held constant for the rest of the simulation until the model reaches “equilibrium” again.
For ECS the most accurate term is probably “step”.
See my post immediately preceding this one (with my computer setup I can only attach one image file per WUWT post)
– – – – –
For TCR we should probably be talking about a “ramp”.
See section 220.127.116.11, “Emulating Process-based ECS to TCR”, page 994 :
NB : Figure 7.17 is attached to the end of this post.
– – – – –
My understanding is that “pulses” should be limited to discussions around “the TRCE concept”.
See, for just one example, in section 18.104.22.168.2, on page 746 :
TRCE = “Transient Climate Response to cumulative CO2 Emissions”
Section 22.214.171.124 = “Assessment of Limits of the TCRE Concept”
Sub-section 126.96.36.199.2 = “Sensitivity to the rate of CO2 emissions”
Yes TCR is for a ramp up. The reason should be obvious. If the pulse is instantaneous then TCR is 0 because TCR is the response at the moment 2xCO2 occurs and since 2xCO2 occurred instantaneously there would be no response yet. As such TCR isn’t a useful metric for analyzing instantaneous pulses.
Pulse just means a mass of carbon (or CO2) that gets injected into the atmosphere. The size of the pulse is irrelevant. The only thing that matters for ECS and TCR is that the atmospheric concentration is doubled. Instantaneous pulses require less mass to get to 2xCO2 vs drawn out pulses because of the carbon cycle.
TCRE is defined per IPCC AR6 WGI Annex VII:
For TCRE both pulse size and duration. The focus of this conversation is not TCRE, but TCR and ECS. The reason is because we are discussing the response wrt to the 2xCO2 state; not a specific pulse size.
A precise example of phony physix.
You must base your regime on the solar luminosity and the continuous hydrodynamic condensing atmospheric equilibrium process.
The factor of 240 is completely arbitrary. It has no basis as a constant around which radiation fluctuates.
Yes. Solar luminosity is something that must be considered. Stellar physics including the luminosity behavior of main sequence stars and the Sun’s documented cycles are hardly what I would call “phony”.
240 W/m2 is not arbitrary. It is the global average flux (or 3.9e24 j/yr) that is absorbed by the Sun. It is ASR or the input portion of the 1LOT. And nobody is suggesting it is constant. It isn’t. And as I recall I’ve been trying to convince you of this (eg the shortwave feedback) over the course of several responses to you even prior to this article.
The hydrodynamic continuously condensing atmospheric equilibrium process is a result of the radiative regime, including total luminosity. The ASR is a consequence.
That has nothing to do with solar luminosity. If solar luminosity drops by 4% tomorrow then the RF is -9.6 W/m2 regardless of what the atmosphere is doing.
that is inconsistent with reality. The global cloud fraction is part of the dynamic equilibrium process.
Considering the existence of cloud is solely due to solar input, a drop of 4% must also impact upon cloud fraction.
A total loss of sun will result in a total loss of cloud.
Likewise, a small reduction of irradiance will result in a small reduction of cloud.
Considering the cloud fraction is related to irradiance, and the albedo is related to cloud fraction, the proportion of solar absorbed is related to irradiance.
A reduction of irradiance results in an increased proportion of that irradiance absorbed.
It is part of the dynamical equilibrium process.
You’re talking about feedbacks. If the RF is -9.6 W/m2 there is going to be cooling and feedbacks associated with that cooling including a change in clouds and ultimately albedo which sets a new ASR/OLR balance point. That doesn’t change the fact that the RF is -9.6 W/m2. I think you’re conflating the concept of radiative force with radiative response. Those two different, albeit related, concepts.
To remain consistent, your virtual radiative force then must be taken from irradiance, not from the equilibrated regime.
A 4% reduction of irradiance is therefore a virtual 340 – (340 x 0.96) = -13.6.
340 yielding a 70% absorption.
340 units of irradiance generating 100 units of reflection.
A simplistic scenario to illustrate:
Taking a minimum cloud generating regime with a temperature just above a critical threshold 273K for evaporation and condensation process, the minimum blackbody power is 315 Wm-2 to generate cloud response.
Today the resulting response factor as 340 – 315 / 100 = 0.25
That is a very strong negative response regime. Each unit of virtual force above freezing imparts a net effect of only 0.25.
The -13.6 virtual irradiance x 0.25 can be estimated as a resulting force of merely -3.4.
A 4% reduction of irradiance may resemble a net solar absorbed of 240 – 3.4 = 236.6. The system is quite very stable once we get above freezing.
And thankfully a non atmospheric system with irradiance 340 Wm-2 generates a planetary effective temperature of 278K.
Certainly right in the sweet spot to generate our climates. It is from there that we compute the consequence of adding atmosphere.
If you like, 278K blackbody force of 340 vs 286K blackbody force real global average temperature 380 yields only 40 Wm-2 as a consequence of atmosphere.
In today’s schematics you might see a 400 Wm-2 surface flux vs 240 Wm-2 TOA, for a greenhouse effect 160Wm-2.
Notice the reality, is the 40 Wm-2 / 160 Wm-2 is a greenhouse sensitivity only 25% or a factor of 0.25 compared to consensus.
I have other ways to derive this, and it is quite consistent. As a rule of thumb, apply a factor of 0.25 to your virtual force to estimate the consequence.
Your virtual force must be computed prior to equilibrium process response to apply the rule.
I forgot to include the comparative reduced irradiance regime:
On the occasion of 4% reduction of irradiance:
326.4 Wm-2 irradiance may generate only 89.8 Wm-2 reflection.
ASR = 236.6.
72.5% is absorbed, vs the 70% today.
“Lewis and Curry 2018 (LC18) matched base periods and final periods based upon volcanism records and the detrended Atlantic Multidecadal Oscillation (AMO). Other possible sources of natural variability, including solar variability, were ignored.”
Well that’s a shame as the AMO envelope is an inverse response to solar wind variability. Every other warm AMO phase is during a centennial solar minimum, which dictates the millennial scale mean AMO frequency of 55 years. The 130 years of the last two AMO envelopes is purely because the previous centennial minimum began 130 years before the current one.
Interesting observation. Thanks.