September 28th, 2019 by Roy W. Spencer, Ph. D.
The radiative resistance to global temperature change is what limits the temperature change in response to radiative forcing from (say) increasing CO2, or the sun suddenly deciding to pump out a 1 percent more sunlight.
If the climate system sheds only a little extra energy with warming, it warms even more until radiative energy balance is restored. If it sheds a lot of energy, then very little warming is required to restore global energy balance. This is the climate sensitivity holy grail, and it will determine just how much warming results from increasing CO2 in the atmosphere.
John Christy and I are preparing a paper based upon Dept. of Energy-sponsored research explaining why the tropical troposphere hasn’t warmed as much in nature as in climate models. (The discrepancy exists for surface temperature trends; for both RSS and UAH tropical tropospheric trends; as well as for global reanalysis datasets). Danny Braswell and I did a lot of research on this subject about 5-10 years ago, and published several papers.
Without going into the gory details of why it is so difficult to measure “feedbacks” (how strong the climate system radiatively resists a temperature change in response to radiative forcing), I’m going to present one graph of new results from our work that suggests where the problem with the models might be.
The plot I will show is based upon month-to-month variations in area-averaged tropical (30N-30S) tropospheric temperatures. When those temperature changes are the largest, we expect to see the clearest signal of radiative resistance (negative “feedback”) which, by definition, is a response to that temperature change. In contrast, if the month-to-month temperature change was zero, any change in radiative flux would result in an infinite feedback parameter, which is clearly unphysical.
So, let’s focus on the biggest observed temperature changes. If we take the 10% of the 224 months of detrended CERES satellite radiative flux data (March 2000 through October 2018) which have the LARGEST month-to-month temperature changes (warming and cooling) in detrended UAH LT data, and compare them, we get the following plot of diagnosed feedback parameter (flux change divided by temperature change) versus average absolute temperature change. Also included in the plot are the results computed in the same manner from 19 different CMIP5 climate models, where I have used the model surface to 500 mb geopotential thickness converted to temperature to approximate the UAH LT product.
There is a clear discrepancy between the 19 different climate models and the observations. The observations suggest a much larger resistance to a temperature change (vertical axis) than the models do, by over a factor of 4, for the same temperature change. This large feedback parameter is probably why the observations also show the smallest month-to-month temperature changes (horizontal axis) compared to the models (about 50% weaker than the models): the radiative resistance to temperature change actually reduces the month-to-month temperature fluctuations.
What Does this Mean?
The results are qualitatively consistent with Lindzen’s “infrared iris” effect, as we find the discrepancy between models and observations is larger in the infrared (LW) component of radiative flux than in the reflected solar (SW) component (SW and LW plots not shown here).
Interestingly, I had to exclude the GISS model results because they show increasing temperatures lead to a feedback parameter with the wrong sign, which is not physically possible for a stable climate system. It could be the GISS model has issues with energy conservation.
Just how these results would impact global warming projections remains to be seen. First, improvements in how tropical convection and its associated clouds and vertical distributions of water vapor *change with temperature* would have to be put into the models. Then, the models would have to be run with increasing CO2 to see whether model projections of warming are reduced.
My prediction is that, if this was done, the models would produce considerably less tropical warming than they currently do. This might also extend to reduced warming rates outside of the tropics, since the tropics export excess heat energy to higher latitudes. If less heat builds up in the tropics, less will be exported out of the tropics.
We have many more results on this issue, including comparisons to a simple time-dependent forcing-feedback model that can replicate both the observations and the CMIP5 model behavior.
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What distinguishes the Earth from the other planets is the vast quantity of very deep surface water. That water holds 99.9% of the planetary heat and acts as a heat sync, plus a hydronic heating system for the northern hemisphere. When the SST is warm, the atmosphere over it is warmed also, particularly at night.
May I recall Trenberth ?
Predictions of climate</a<
Dr. Roy’s observations are consistent with the change of climate regime that occurred around 1995. I explain this here:
http://breadonthewater.co.za/2019/09/22/revisiting-the-87-year-gleissberg-solar-cycle/
Looking at it only from 2000 might give a wrong impression but it does tell you what lies ahead…..
As the temperature differential between the poles and equator grows larger due to the cooling from the top, very likely something will also change on earth. Predictably, there would be a small (?) shift of cloud formation and precipitation, more towards the equator, on average. At the equator insolation is 684 W/m2 whereas on average it is 342 W/m2. So, if there are more clouds in and around the equator, this will amplify the cooling effect due to less direct natural insolation of earth (clouds deflect a lot of radiation). Furthermore, in a cooling world there is more likely less moisture in the air, but even assuming equal amounts of water vapour available in the air, a lesser amount of clouds and precipitation will be available for spreading to higher latitudes. So, a natural consequence of global cooling is that at the higher latitudes it will become cooler in winter and drier & warmer in summer. Obviously with more clouds and rain around the equator & lower latitudes you will get less warming there or even cooling – clouds reflect a lot of radiation.
As far as the mechanism is concerned: as the sun’s solar polar magnetic field strengths are going lower, it seems plausible to think that more of the most energetic particles are able to escape. Earth’s atmosphere protects us against these particles by forming more ozone, peroxides and N-oxides. In turn, as these substances increase TOA they deflect more incoming SW radiation to space. A strange paradox: the sun is getting hotter making the earth cooler….
just as an example I show the Arosa ozone time series. Clearly you can see the turning point of around 1995?
Every time I read the comments here I am amazed at the amount of scientific knowledge available about things that we have absolutely no control over.
Very well said.
It looks like models treat all EMR (radiation) the same way. As so many W/m²; whether sunlight or infrared. Yet it’s not all the same from the point of view of surface warming. Sunlight penetrates many metres into water. DWIR penetrates mere micrometres, so warms only the surface skin. Re-emission at the surface can only penetrate downwards another few micrometres, but there’s no barrier to upward re-emission. Conduction downwards is slow, and convection impossible because the lightest water is at the surface. Much of this surface skin warming will goes latent heat, evaporating water, which condenses at the upper troposphere, releasing it’s latent heat here, so effectively cooling the surface. Isn’t this a fundamental error by the climate modelers – treating all EMR the same for the purposes of surface warming? Why don’t people make a bigger deal of this?
Indeed solar and LWIR behave differently with regard to penetration, but there are other processes occurring simultaneously long with it. For example, there is evaporation. Also the ocean is not a glassy pond. It is roiled by wind and surface waves along with some convection so that an upper layer becomes mixed. This convection is not exclusively thermal, but is also the result of salinity changes. Surface evaporation cools the surface and makes it more saline. Often one can see the results of surface convection in streets of foam and debris lined up in the prevailing wind direction (roll cells). It is a complicated problem of combined mass and heat transport.
Accordingly, surface evaporation makes the top surface more saline, so more dense, so it sinks and we have convective mixing. Makes perfect sense.
Thanks. Likewise to Roy.
But we surely agree LWIR cannot be treated in the same way as shorter wave sunlight? Just another model defect I guess. Modelers are so certain, they’re ignoring every criticism, and will put this in the bin too.
Mark:
It’s a good question. I’m not aware of any modeling to address the issue. But clearly IR radiation is important to the ocean heat budget, because the ocean almost everywhere is losing IR energy. So, if you reduce that loss, then ocean temperature will change. The ocean mixed layer is always experiencing mixing from waves, and even evaporation causes mixing by creating a cool skin that is more dense than just under the skin.
“My prediction is that, if this was done, the models would produce considerably less tropical warming than they currently do. This might also extend to reduced warming rates outside of the tropics, since the tropics export excess heat energy to higher latitudes. If less heat builds up in the tropics, less will be exported out of the tropics.”
Not while low indirect solar is driving a warm AMO phase (via negative NAO/AO) and reducing low cloud cover in the mid latitudes, and increasing cloud cover in the Arctic. That’s where most of the post 1995 surface warming has arisen, as well as the increase in upper ocean heat content.
Geeee…
I have just started my coal fire to start a barbecue. What a relief to know that I am not warming the earth…
Better question: why has the arctic warmed so much?
griff
I did investigate this.
By my results, it seems that the inner core of earth has traveled NNE, especially fast in the past 100 years or so, as proved by the position of the magnetic NP…
It shows up in my results. The average minimum T has gone down here, in the SH whereas in the NH it has gone up.
We call kt the magnetic stirrer effect,
IOW, it is the inside of earth re-aligning itself with the inside of the sun.
Come here, to South Africa, and let me take you down into a gold mine here. Discover the real elephant in the room that nobody even talks about…
Still better question, why has the Arctic so much been colder the last 800 years than the previous 9000?
A combination of the AMO and El Nino.
Having the coldest places on the planet warm up a few degrees isn’t a problem.
griff
I did investigate this.
By my results, it seems that the inner core of earth has traveled NNE, especially fast in the past 100 years or so, as proved by the position of the magnetic NP…
It shows up in my results. The average minimum T has gone down here, in the SH whereas in the NH it has gone up.
We call kt the magnetic stirrer effect,
IOW, it is the inside of earth re-aligning itself with the inside of the sun.
Come here, to South Africa, and let me take you down into a gold mine here. Discover the real elephant in the room that nobody even talks about…
Geee,
what a lovely supper we had,
knowing that there is no such thing a man-made global warming.
I am worried, though, about the natural climate change, that is coming to cause the droughts.
[click on my name]
I am sure Greta and her friends from the extinction rebellion are ready to take the lead once despair about the food inflation has taken a hold.
There are natural cycles diurnal, annual, decadal and most likely centenary and millennial which would in turn enhance and suppress effect of any positive or for that matter negative feedback, of which might be more than just one.
Dr. Spencer, great work as usual. I’m working with some students on a Science Fair Project, and I hope you don’t mind us using some of your research. Currently, we’ve been working on a project that is using the ground measurements to disprove the CO2 Climate Change Theory, and you may want to take a look yourself.
You can filter for all the ground stations that existed in 1902 when Michael Mann started adding them to his Hockey Stick. If you control for the Urban Heat Island Effect, you will find that basically none of the ground measurement stations show warming since 1902. The warming Michael Mann claims happed in the last century simply isn’t supported by the empirical data.
https://data.giss.nasa.gov/gistemp/station_data_v3/
Here is the best example I’ve found.
https://data.giss.nasa.gov/cgi-bin/gistemp/stdata_show_v3.cgi?id=501943260000&dt=1&ds=7
Anyway, real science only needs one example a model can’t explain. GISS provides countless examples that can’t be explained by CO2 causing warming.
Dr Spencer, I have heard Mann speak about the Pacific Thermostat Hypothesis as a reason why the Medieval Warm Period would have seen lower temperatures in the tropics. When asked a question about whether this same phenomenon would operate in response to global warming, and thus warming in climate models is ‘vastly overstated’, Mann responded that he agreed and he thinks there is a missing negative feedback.
How laughable! Doesn’t he know it is not the models that are off it is reality that has the problem? Geez, everyone knows that!
Why Haven’t the Tropics Warmed Much?
Well, it seems like the headline of this blog post is wrong, if Dr Spencer is referring to to the temperature trend of the tropical troposphere 2000-2018 (30 N – 30 S), as indicated by the change of the 500 mbar geopotential height.
As a rule of thumb, a 20 m change of the 500 mbar height, translates to approximately 1 C change of the bulk temperature of the air layer from the surface up to 500 mbar.
The newest and most advanced reanalysis, ERA5, has a trend of 6.4 m/decade in the 500 mbar height (tropics 30 N – 30 S, 2000-2018). This is around 0.32 C/decade
(data ESRL/WRIT)
The CMIP5 rcp4.5 multimodel mean for the same period and region is 5.6 m/decade, or 0.28 C/decade
(data KNMI climate explorer)
It is possible that “Why Haven’t the Tropics Warmed Much” refers to Dr Spencers own dataset, UAHv6 TLT, which has the trend 0.13 C/decade in 2000-2018, 30 N-30 S.
However, this dataset is a cool outlier in the 21st century, with the clearly lowest trend of all satellite, radiosonde, and reanalysis products.
Olof
whatever all you guys are doing to ‘show’ it is getting warmer, obviously you are doing something wrong.
in fact, it is getting cooler
https://documentcloud.adobe.com/link/track?uri=urn:aaid:scds:US:42f86fb5-bd3a-4bce-a1d2-2e33fe3fa66b
click on my name to read my report…
I took a look.. perhaps you meant it is getting warmer more slowly.
None have crossed the zero line into negative territory. Only past the peak accelaration.
Thanks Roy for this thoughtful article.
Incident sunlight contains a lot of IR:
https://images.app.goo.gl/ZwburEGRX3VoKvke8
It is sometimes said or implied that sunlight is shortwave visible light only with no IR, and IR is only present in radiation out to space from earth. But this is not true. Sunlight has a lot of IR. That’s why it warms your face.
Therefore CO2 will backradiate out to space some of the incident IR in sunlight. (This phenomenon does not only occur at the earth’s solid surface.) So increasing CO2 in the atmosphere will actually reduce the incident solar energy at the top of atmosphere due to this back-radiation.
The heat energy transferred from earth’s surface upward into the atmosphere, within the troposphere at least, is transferred primarily by convection, not radiation. Warm land surface warms the air which rises, etc., and we get clouds and weather. Actual flux of radiation including IR upward at the surface is much less than in incident downward sunlight, since most vertical heat transport is by convection, not radiation. Upward and downward radiated heat would only balance on the moon or another space body with no atmosphere. And especially no water in that atmosphere.
(Heat export to space for overall global heat balance at the emission height is of course by radiation. But transport of heat to that height, upward from the surface is by both radiation and convection, mostly the latter.)
Here’s the temperature profile of the atmosphere:
http://apollo.lsc.vsc.edu/classes/met130/notes/chapter1/graphics/vert_temp.gif
In the troposphere, temperature declines with height as higher air layers receive less and less convective warming from below. Here, radiation will play a much lesser role especially in the presence of water vapour with its large heat capacity. Flow of water heat in the atmosphere is predominantly by convection not radiation. And water vapour dominates the heat budget in the troposphere.
Above the troposphere temperature zig-zags up through the stratosphere, mesosphere and ionosphere. Air is now much less dense with no water present. So the thermal effect of convection declines and direct solar irradiation predominates. However the picture is complicated by local solar heating phenomena restricted to specific layers: radiative heating of ozone at the top of the stratosphere and by cosmic ray ionisations occurring in the (thus named) uppermost ionosphere. Thus the temperature zig-zags.
(As the stratosphere is heated from above by the sun, CO2 back radiation rejects some of this radiative solar heat energy. Therefore increasing CO2 reduces the solar warming of the stratosphere, causing the stratospheric cooling that is observed.)
Some downward convective movement of heat in the atmosphere also occurs in the troposphere. This is the only layer that is dense enough for convection to be significant. Thus some downward convective heat transfer will occur from the upper sunlight-warmed troposphere. If downward and upward thermal convection equalled each other then a uniform temperature would pertain. But this is not the case. Downward convective heat movement does not balance upward because of the density gradient. Warmer air heats neighbouring cooler air more effectively when the warm air is more dense – it has disproportionately more energy. Thus on balance convective heat movement upward predominates over downward, and as a consequence the troposphere cools – rather than warms – with height. And density, dare one say it – is caused by 9ravity. It one is still allowed to believe in that g-word.
It is at the bottom of the troposphere at the earth’s surface where relevant weather and climate occur. Here the radiation fluxes are not in balance (as AWG erroneously implies) but the flux downward from the sun is much stronger than the flux upward from the land surface. Remember / energy from the sun is by radiation only (much less convection due to the density gradient) while upward heat transport in the troposphere is mostly convective. If it were otherwise, then we would warm our face by stooping and facing the ground, rather than looking up toward the sun ☀️ . (You might warm your face from car-park asphalt, but not from the surface of the sea.) The upward and downward fluxes of heat are of course in approximate equilibrium but the majority of the upward heat transport is by convection.
CO2 cuts out some IR photons out of a mixed electromagnetic wavetrain. It cuts out more IR from incident sunlight at the upper atmosphere (mainly stratosphere) by back-radiation. It cuts out less IR from radiation from earth’s surface since this radiation flux is much weaker than incident sunlight. Therefore overall CO2 will exert a cooling effect on climate since it effectively reduces TSI, the heat energy incident on earth from the sun, due to the CO2 back-radiation to space. The atmosphere is well mixed with CO2 all the way up to the top of the mesosphere.
One’s face is a sensitive and accurate radiation detector to allow one to physically perceive the falsehood of the CO2 back radiation warming conjecture. It’s enough just feel the warmth of the sun on your face.
Why Haven’t the Tropics Warmed Much?
This seems a very strange question.
Climate warms by transferring more heat from equator to pole, not from uniformly heating everywhere. This is obvious.
Consider earlier times such as the Mesozoic (Triassic-Jurassic-Cretaceous) when dinosaurs lived. Forests extended to the poles. Climate temperature was 10-12 degrees C warmer than now.
Imagine tropics 10-12 C hotter than now. Maximum temperatures would start to cook meat and life of vertebrates like dinosaurs and mammals (that already lived then) would not be supported. Plants and trees would die of dehydration and heat stress. And we know that this did not happen.
Willis Eschenbach has explained that the thundercloud feedback caps the temperature of the ocean surface not much higher than 30 C. The oceans have to be evaporated dry before tropical temperatures increase much above this.
So equatorial temperatures haven’t changed much since there has been land at the equator. So all climate warming is just more heat transport to the poles by ocean circulation and less difference in temperature equator to pole. Conversely cooling is reduced heat transport poleward. All the while, the tropics stay the same.
All this is blindingly obvious.
So of course warming and cooling will be “amplified” at the poles. To make such a statement with a flourish (e.g. as Griff does) as if some profound discovery has been made, is simply to expose the fact that one has never really thought deeply or seriously about climate.
Google Canadian Ice Services for a look at variations in the Arctic ice. There is a slight drift down, but not dramatic.
https://iceweb1.cis.ec.gc.ca/Prod/page2.xhtml?CanID=11081&lang=en&title=Western+Arctic
https://iceweb1.cis.ec.gc.ca/Prod/page3.xhtml
https://ice-glaces.ec.gc.ca/prods/CVCHACTGL/20190513180000_CVCHACTGL_0010581626.pdf
What so many seem to miss is the law of radiative emission that states that a body radiates at the 4th power of its temperature. (simplified).
What that means is that ‘if’ a temperature change is felt on earth for any reason the RATE of radiation will increase, not logarithmically, but by the 4th power of that temperature change. We all see this daily. The input source is the sun, not Co2. We warm by day, but the RATE of radiation increases during the day, so far more radiation occurs when the sun is shining. At night, when the input is zero, the radiation RATE drops throughout the night, as the surface cools. Sun heats the earth quickly, but radiation at night is slow, but sufficient to displace most of the daily sun. As days get longer, the air temperature increases, and the RATE of radiation from the surface increases – by the 4th power of that temperature change. That’s a LOT of feedback and control. Most people don’t understand what the 4th power means in a feedback system, but that is exactly how the earth sheds its heat load, every day. It is a thermostat that has a HUGE ability to lose heat. The only way earth will actually warm more than it already has is if the input increases. One part Co2 in 2400 parts of ‘air’ can logically not have any affect on the climate. For any one photon hitting earth, there are millions of molecules of solid or liquid radiating away. The 2400 molecules of air would cool the one molecule of Co2 by collisions – the gas laws don’t permit different gases to be different temperatures in a given volume and pressure.
Except for the two facts that (1) not all blackbody radiation from Earth’s surface travels directly to deep space, and (2) low density, non-ionized gases, as found in the upper troposphere (particularly water vapor and CO2) and above the tropopause (particularly CO2), do NOT produce blackbody radiation at any naturally-occurring temperatures.
John
Can you clear up for me the 4th power relationship.
If the temperature of a body increases by a factor x, does the radiation from it increase according to x ^ 4? Or according to x ^ (1/4) ?
Dr. Spencer,
I went through the Mechanical Engineering degree at U of Michigan, a top school, actually there on an academic scholarship due to a National Merit Scholar award.
This degree involves Thermo 1, Thermo II both with labs, and then Fluids, and then Transport of Heat and Mass, all of which included a lot about radiative heat transfer.
Clearly you did not study these subjects.
The CERES satellites have never been calibrated, hence unreliable. Likewise historic temp records. UAH and RSS temp data are far better than any historic records of thermometers, but only extend back to 1979.
And, by the way I schooled your friend Mosher on how this works, ask him.
So: CO2 Effect is Logarithmic. No, not so much, 280 ppm is enough already to saturate the absorption and thermalization of 15-micron LWIR at around 10 meters above the Earth’s surface. Additional CO2 can lower this altitude by maybe one or two cm.
So, Significant effect of additional CO2 occurs at TOA, where additional CO2 raises the altitude at which 15-micron radiation can escape to space, lowering the temperature at which the atmosphere is freely able to radiate to space, lowering the amount of heat escaping to space, raising the amount of heat retained in the atmosphere. Unarguable.
But, no one can calculate the magnitude of this effect! I know, I tried, lots of others have, cannot be calculated.
This means that all “Calculations” of Transient or Equilibrium Climate Sensitivity are based on an assumption, that all so-called measured heating since 1880, or 1850, or some year, is due to CO2!
Hardly a scientific assumption, you should all make that clear, and, you should all be ashamed of yourself, your nonsense has doomed millions around the world to energy poverty….
Why do you say CO2 is saturated. Have you heard of pressure broadening (Phys Chem 101) ?
Minuscule delta on LWIR absorption.
Michael Moon
Apart from the fact that you are really a very arrogant person, let me tell you that your view on CO2’s activity within our atmosphere hardly could be more trivial.
1. “So: CO2 Effect is Logarithmic. No, not so much, 280 ppm is enough already to saturate the absorption and thermalization of 15-micron LWIR at around 10 meters above the Earth’s surface. Additional CO2 can lower this altitude by maybe one or two cm.”
I thought nobody today would be ignorant enough, Mr Moon, to relate CO2’s radiative activity to the surface, where it is absolutely insignificant wrt H2O aka water vapor. Even a simple layman like me doesn’t.
What CO2 does happens far above, namely where H2O no longer is able to, because it has precipitated kilometers below.
While H2O is absent above the tropopause, CO2 is uniformly present in the atmosphere, up to 50 km altitude.
Please manage to
– translate the following article from French into English (I’m too lazy to do), to
– try to understand what these two scientists told us, and to
– accordingly update your knowledge.
https://www.sauvonsleclimat.org/images/articles/pdf_files/etudes/article%20dufresne-treiner%20basse%20def.pdf
I’m sure you will learn a lot – iff you are able to bypass your inner barriers, of course.
2. “Hardly a scientific assumption, you should all make that clear, and, you should all be ashamed of yourself, your nonsense has doomed millions around the world to energy poverty….”
Who are you Sir, to discredit a person like Roy Spencer?
Show us your scientific achievements!
Rgds
J.-P. D.
13.9 billion years ago the Big Bang happened.
First there was a crazy fraction of a second, including the weird “inflationary” phase.
Then followed the “light epoch”.
This was the period dominated by light.
Photons were so dense that matter particles could not coalesce, and the universe was opaque.
This light epoch lasted about 300,000 years.
Then the universe thinned enough to become transparent to light and for particles and atoms to form. Thus the light epoch ended and the matter epoch began. It has lasted until now and will continue till the end of the universe.
Proponents of CO2 back radiation warming appear to believe that we are still in the universe’s light dominated epoch. They explain all thermal interactions in the atmosphere as resulting from and involving radiation only.
This is false and weird. The light epoch is over, and has been since 300,000 years after the Big Bang.
Thus vertical movement of heat in the atmosphere, critically the heat transport from the earth surface to the emission height, is largely by convection, not radiation. CAGW is based on a huge error of fundamental cosmology (as well as everything else wrong with it).
“When those temperature changes are the largest, we expect to see the clearest signal of radiative resistance (negative “feedback”) which, by definition, is a response to that temperature change.”
Isn’t already the choice of words wrong – after all, the world climate is a machinery, a climate machine such as the air conditioners in vehicles and homes. So technically we come from feedback to shock absorbers and – dampers:
When those temperature changes are the largest, we expect to see the clearest signal of radiative resistance by friction losses in the atmosphere, namely dampers, which, by definition, are due to the elevated system’s heat capacity,
https://www.google.com/search?q=brownian+motion+definition&oq=brownian+motion&aqs=chrome.