Guest Post by Willis Eschenbach
Well, after my brief digression to some other topics, I’ve finally been able to get back to the reason that I got the CERES albedo and radiation data in the first place. This was to look at the relationship between the top of atmosphere (TOA) radiation imbalance and the surface temperature. Recall that the IPCC says that a change in the TOA radiation of 3.7 W/m2 from a doubling of CO2 will lead to a 3°C ± 1.5°C temperature increase. This 3°C per doubling is called the “climate sensitivity”, and its value is an open question.
Figure 1, on the other hand, shows my results regarding the same question of the climate sensitivity. These reveal nothing like a 3°C temperature rise from a doubling of CO2:
Figure 1. Gridcell-by-gridcell linear trends of the change in surface temperature (∆T) given the change in TOA radiation (∆F). Note that the surface temperature data is gridded on a 5°x5° gridcell, while the CERES TOA radiation data is on a 1°x1° gridcell basis. Graph includes a two-month lag between change in forcing and the change in temperature.
There are a variety of interesting aspects to this particular graph. Let me start by describing how I constructed it.
I began by taking the gridded HadCRUT3 temperature data for the period of the CERES study, Jan 2001 to Oct 2005. The HadCRUT data is on a 5°x5° gridcell, so I first expanded that to 1°x1° gridcells. Then I took the first differences (∆T) by subtracting each month from the succeeding month, to get the monthly change in temperature (∆T) in each gridcell.
Then I compared that ∆T dataset to the change in TOA radiation (∆F), which was constructed from the CERES TOA data. For each gridcell, I took the linear trend of the temperature changes ∆T with respect to ∆F.
Of course, the climate sensitivity results from this procedure are in units of temperature change per forcing change, which is °C per watt/square metre. To convert it to change in temperature per doubling of CO2, I multiplied the results by 3.7 W/m2 per doubling of CO2.
Finally, I needed to adjust for the lag in the system. I did this in two ways. First, I selected the lag which gave the largest temperature change, which was a two month lag. These are the results shown in Figure 1. However, this is a cyclical record of the annual fluctuations, so the equilibrium sensitivity will be underestimated. Per the insights gained from my last analysis, “Time Lags in the Climate System“, the time lag is related to the size of the reduction in temperature swing. A 1-2 month lag in the system indicates a reduction in fluctuation of about 50%. So for my final adjustment, I doubled the indicated climate sensitivity. The results of this are the values shown in Figure 1.
Now, I have long argued, solely from first principles, that climate sensitivity is a non-linear function of temperature. I have said that the sensitivity was greater when it is colder, and that it is smaller when it is warmer. I have held that this relationship was non-linear, with a kink at the temperature range for tropical thunderstorm formation. Finally, I have also argued that in some places in the tropics the climate sensitivity is actually negative, due to the action of tropical clouds and thunderstorms.
To test these claims, I plotted the sensitivity for each gridcell shown in Figure 1 against the annual average temperature for that same gridcell. The results are shown in Figure 2. As far as I know, this is the first observational evidence that shows the actual relationship between climate sensitivity and temperature, and it supports all of my contentions about that relationship.
Figure 2. Scatterplot of gridcell climate sensitivity versus gridcell temperature. Colors indicate the latitude, with red at the tropics, yellow in the temperate zones, and blue at the poles. Gray dashed line shows the linear trend, indicating that the climate sensitivity varies generally as -0.009 * temperature + 0.32 (p-value < 1e-16).
There are some important things about this plot. First, it strongly supports my claim that the climate sensitivity varies inversely with the temperature. Next, it shows that a number of areas of the tropics actually do have negative climate sensitivity. Finally, it shows that the relationship is non-linear with a kink at around the temperature for the formation of tropical thunderstorms. This is important corroborative evidence for my hypothesis that the tropical clouds and thunderstorms act as governors of the tropical temperature and are the source of the negative climate sensitivity.
Let me close by railing a bit against the pernicious nature of averages. Consider Figure 2. Normally, far too many climate scientists would take an average of that data, and come up with some number as the average climate sensitivity. But that number is meaningless, and worse, it gives the impression that the sensitivity is a fixed number. It is nothing of the sort. Not only is it not fixed, it is far, far from linear, and it goes negative at times. It is a dynamic response to changing conditions, not some fixed value.
As a result, when we average it, we come away with entirely the wrong impression of what is happening in that most complex of phenomena, the climate system. While averaging is often useful, it conceals as much as it reveals, and it can lead one to badly erroneous conclusions. That is why so many of my graphs and charts show thousands of individual points, as in Figure 2. Only by seeing the whole picture can we hope to understand the system.
My best to all,
w.
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Here is the WUnderground tropical storm summary graphic. Notice the area bounded by the dotted line. It it the boundary of the area that spawns hurricanes. Lower surface temperatures are too cold. On the bar below the graphic we can see that that boundary temperature is about 25.8 deg C, just the temperature at which your scatterplot heads decisively below zero.
One other thing. The fact that your plot shows that the temperature rise for a doubling is about 0.3 C does not mean that the feedback from convection is positive. You should make this clear.
Once again, a fine piece of work.
http://www.wunderground.com/tropical/
ajstrata says:
June 19, 2012 at 11:22 am
Thanks, ajstrata. While you are correct, the difference is miniscule. The earth’s radius is about 6,378 km. The TOA is at say 15 km. The difference in the surface area of those two spheres (surface and TOA) is about half a percent. Since few of our measurements are that accurate, the difference in area is generally ignored.
Also true … but I’m not clear what that has to do with net TOA radiation.
w.
These are really great analyses Willis. Looks like climate sensitivity is kinda like ocean oscillations, dynamical, non-linear, and inherently oscillatory. The T-dependence sounds very logical. I’ve watched thunderstorms explode just off shore in the Gulf of Mexico and the magic water temperature is 29 C or 84 F. It’s truly amazing. Bravo Zulu.
-Frank
Willis,
Thanks for a neat bit of evidence which is good for supporting the contentions of both of us.
Now, I just need to persuade you:
i) to extend your thermostat hypothesis beyond the tropics so as to include latitudinal shifting of all the climate zones,
ii) acknowledge that there can be a top down solar effect on the AO and AAO to offer resistance to the latitudinal shifting that occurs in response to your tropical thermostat and
iii) hopefully one day acknowledge that average global atmospheric surface pressure has a bearing on the maximum sea surface temperatures that can be achieved before the convective response eliminates any further energy gains at the surface.
Best wishes.
eyesonu says:
June 19, 2012 at 10:44 am
Willis, you keep rattling the cage with that hammer of yours.
—————————————————————————————————————————
Here Here ! Willis Eschenbach the 21st Century Michael Faraday of Climate Science.
Totally at your best with this one, it’s beginning to look like the major work has been done.
” the pernicious nature of averages” was acknowledged, too.
please comment on the geographical component with respect to the poles and the stabilizing influence of phase change ice/water.
(if you have seen farther than others, it’s not because you stood on the shoulders of midgets- it’s because you were a giant.)
Willis Eschenbach says:
June 19, 2012 at 11:47 am
==============
You are for real!
With all the garbage that has been published over the past several years there’s not much honor in publishing in a journal. Just look at what has happened to the Nobel Prize selection process, little honor there either.
A co-author sounds good but we like you here. You are having an impact by proxy. I pass my knowledge along to my ‘green’ friends. Some are no longer friends but most are no longer ‘green’.
Stephen Wilde says:
June 19, 2012 at 12:20 pm
I think that there are thermoregulatory mechanisms operating at a host of scales. Whether one of them is “latitudinal shifting of all the climate zones” is not at all clear to me. I have written here and here about the “widening of the tropics” and the difficulties in measuring it … which of course only increases the difficulties in understanding it.
Haven’t a clue what that means, a “top down solar effect on the AO and the AAO”. I mean I know what the AO and the AAO are, but I don’t know what a “top down solar effect” is when it’s at home.
Like the other two, I’m not sure either what that pressure effect is or how it might be measured or established …
Steven, all of those are fine, noble hypotheses, and all of them could be true … or not. What you need is data. You need to do what I’ve done, which is root around and find datasets and use them to demonstrate that your ideas are borne out by observations.
In any case, this thread is about my findings, and so solar effects on the AAO are wildly off-topic, but if you have a web site that expounds and clarifies your ideas, feel free to post a link.
All the best to you,
w.
Thank you again Willis. Very interesting analysis.
Another story I like about averages is about the man who drowned in a stream the average depth of which was 16 inches.
Climate science is terrified to go there, but big picture tells it all, from pole to pole, not to mention the South Atlantic anomaly.
http://www.vukcevic.talktalk.net/GT-MF.htm
Right on pointy about averages. The average person has one testacle and one ovary.
I have wondered why nobody has attempted to calculate sensitivity from the daily and seasonal variations in TSI and temperature. Surely if 3.7 w/m2 leads to a 3 C rise then daily and seasonal fluctuations in temperature would be much more severe. For example for Sydney the difference in average T summer / winter is 12 C. The difference in TSI is about 300 w/m2. This leads to a sensitivity of 0.04/w/m2 or about a 0.2 C for a doubling of CO2. I realise that equilibrium is not reached and if the 300 w/m2 were held for a longer period the average T difference will increase. Even if the true difference was double , say 24 C it is still only a 0.4 C per doubling. At 3 C per 3.7 w/m2 the expected difference between summer and winter is 240C Eh?
Willis said:
“I don’t know what a “top down solar effect” is when it’s at home.”
I don’t want to derail this thread by going into detail here but you may be interested in this:
http://climaterealists.com/index.php?id=6645
“How The Sun Could Control Earth’s Temperature”
The ideas expressed have been holding up well during the current low solar activity and I think such a top down mechanism needs to be added to your oceanic thermostat hypothesis to produce a more complete climate overview.
As regards data, there isn’t much as yet but a number of new sensors are accumulating more useful data over time and in due course will prove or rebut my suggestions well enough.
another one is about the statistician who was found with his head in the oven and his feet in the freezer. he was dead, but on the average he was quite comfortable.
Willis I recall that Bill Illis posted a link to a graph which showed there was no greenhouse effect at the tropics and that the GHE became greater the further away from the tropics. Is this perhaps related in some way to your analysis here? Sorry I cannot find the link but I have no doubt Bill will be along in due course.
Keep up the good work
Willis said:
“Like the other two, I’m not sure either what that pressure effect is or how it might be measured or established …”
You could try this because it helps your ideas but I am somewhat circumspect about mentioning pressure to you:
http://climaterealists.com/index.php?id=7798
The Setting And Maintaining Of Earth’s Equilibrium Temperature”
Willis Eschenbach said (June 19, 2012 at 10:56 am):
“…Possible, bacullen, but the problem is that we lack data near the poles. I have only calculated the trend in gridcells with a minimum of 36 data points (out of a possible 58 months of data), so a number of the cells near both poles haven’t been calculated…”
Why don’t you “extrapolate” the Arctic values like Hansen does?
/sarc, of course.
Also, you realise that there are those who feel that your choice of HadCRUT3 will be wrong (example, SkS stated that HadCRUT3 “…has a known cool bias and has of course been replaced by HadCRUT4…”
They state that there is simply no reason to be using the outdated data from HadCRUT3.
We know and understand the reason – the HadCRUT3 data doesn’t extend into the period of the CERES data.
But they’ll use that “cool bias” of the HadCRUT3 to say you’re way off.
@fredb
The problem right now is that major journals are unlikely to publish anything outside mainstream academia. This block on work by skeptics must eventually change as evidence, like that given by Willis, grows to support lower climate sensitivity and net negative water feedbacks. Model predictions of warming have been reducing gradually since 1990 to be remain consistent with the temperature data. This trend has been missed in the media/poltical sphere which continue to quote figures of up to 6 degrees warming by 2100.
I suspect that the key paper putting to rest CAGW will have to be from someone within the climate science community ! Frustrating I know.
Gary W says:
June 19, 2012 at 1:07 pm
I have wondered why nobody has attempted to calculate sensitivity from the daily and seasonal variations in TSI and temperature.
””””””””””””””””””””””””””””””””””””””’
Interesting thought. Sunlight, falling on the Earth when it’s about 3,000,000 miles closer to the sun in January, is about 7% more intense than in July. Yet, because the Northern Hemisphere has more land which heats easier then water, most people state that the Earth’s average temperature is about 4 degrees F higher in July than January, despite the fact that the TOA flux is 7% higher in January, when in fact they should be stating that the stating that the ATMOSPHERE is 4 degrees warmer in July. In January this extra SW energy is being pumped into the oceans where the “residence time” within the Earth’s ocean land and atmosphere is the longest. There are also other factors, such as the Northern hemispheres winter increase in albedo exceeds the southern hemisphere’s winter albedo due to the far larger northern hemisphere land mass. So at perihelion we have a permanent loss to space of ? W/2m SWR due to increased albedo and a temporary loss of SWR to the atmosphere, as at perihelion the SWR is falling on far more ocean, where it is absorbed into the oceans for far longer then if that SWR fell on land. Do these balance (unlikely) or is the earth gaining or losing energy during perihelion??? The TOA seasonal flux should tell us and climate models should accurately predict the observation. In Janauary much of this extra TOA influx may also beabsorbed in water vapor formation and cloud formation. This seasonal flux in TOA radiation far exceeds anything CO2 may affect.
Willis, do you think there is adequet observations of TOA seasonal flux, seasonal water vapor and clouds, averaget T change, etc, to see what kind of variable sseaonal enstivity exists?
I also note that you say you do not have observations for the polar regions. I understand this, but
TOA energy flux can not be averaged either. In other words it takes a far larger energy influx to change 89 F to 90 F, then it does to change -10 f to -9 F.
Well that’s…certainly interesting. In order for it to be true, wouldn’t it require that changes in temperature in the tropics and higher latitudes vary in opposite directions? Because they mostly don’t.
Of course, it would have perfectly described our understanding of the Eocene…before the usual suspects “fixed” the data that showed cooler tropics and warmer poles to also show marginally wamer tropics. And now argue they that the data for the tropics during the period should be adjusted even warmer!
Just in case I’m not the only one who hasn’t yet worked this through, could you explain a little further how the relationship you obtained in your last post, i.e., “the time lag is related to the size of the reduction in temperature swing,” applies here, i.e., how you arrived at multiplying the sensitivity by two?
In that post, the lag and attenuation at issue were between surface and sub-surface temperatures; i.e., both quantities were temperature, and the system is one in which the connection between the two is heat conduction. Here the lag is between changes in top-of-atmosphere net radiation and changes in surface temperature, i.e. the quantities differ, having a derivative/integral relationship, and you’re taking differences in both.
I recognize that, as your last post suggested, the diurnal and annual (extra-tropical) lags’ being equal fractions of the stimulus period strongly suggests that the processes are mathematically analogous, but I was wondering whether you (or someone else here) had a good idea why. And I was wondering about why here it’s the quantities’ first differences rather than the quantities themselves, which (if I understood it correctly) the surface-temperature / subsurface-temperature post dealt with.
Interesting graphs, Willis. And interesting paper, Stephen. My only objection (to both) is that it could be more complex than either or both together. Stephen already made part of this point in his paper where he noted that the prior state of the oceanic heat sink can significantly modulate the responses he suggests. Prior state includes prior state of the major decadal oscillations — ENSO, for example, is clearly a major modulator and trigger for Hurst-Kolmogorov-like stochastic steps in SSTs (Bob Tisdale). The PDO has long been recognized as a major player in the organization of the jet stream and heating/cooling trends, especially in the Arctic, and the NAO almost certainly plays a similar role although one that is not as strongly correlated.
Then there is the wild card, maverick science — e.g. Svensmark. So far as I know, his hypothesis hasn’t been disproven — it works “in vitro” as it were (in cloud chambers) and may be a neglected modulator of the albedo as well.
The problem is that we don’t know, because even if Svensmark is right and cosmic ray modulation is a second modulating factor that Stephen should consider in his stratosphere-mesosphere model (after all, that NO_2 is a potential aerosol that can help nucleate clouds AND destroy ozone, and is produced in thunderstorms for possible positive feedback to amplify or attenuate any baseline responses) there is SST variation and the phases of the DOs to consider so that a solar magnetic state fluctuation at the wrong time might have a very small response, where the same fluctuation at another time might have a strongly magnified response.
I’m just not seeing people “get it”. The climate is a chaotic system. As such, its time evolution is highly non-Markovian — its state tomorrow doesn’t just depend on its state today plus any changes in its primary drivers today, it depends on its state last week, last month, last year, last decade, and probably last century or more. It is at least bistable, where we are in the less stable (warm) branch, given the evidence of the last million years or more and where there is at least some evidence — the LIA being the coldest part of the entire Holocene post the Younger Dryas, for example — that the Holocene may be growing unstable not in the warm direction but in the cold direction. The CAGW folks are all concerned with annual or decadal time scales, but the climate varies on century time scales. The entire 20th century neatly disappears on any graph that illustrates temperatures over the last 500,000 or 1,000,000 years, and it is only on these latter scales that things like the glacial/interglacial oscillation reveal themselves.
So much is I love Willis’s graphs, and agree that there is almost certainly negative feedback/sensitivity from cloud-based albedo (as suggested by Roy Spencer in his book, IIRC), and agree that he makes a strong case for this from actual data, it isn’t strong enough in and of itself to explain “the climate”, only a single, fairly local, response function contributing to it. Stephen’s paper casts a wider net, connecting solar state to climate, but still not wide enough. Bob Tisdale’s papers do a marvelous job of analyzing the connection between global temperature, SSTs, and the ENSO in particular, but neglect the direct feedback Willis portrays or the indirect jet stream mediated opening or closing of a tropical heat source for the oceans that provides direction to the changes observed by Bob. Koutsayannis analyzes long term climate trends and finds them nearly random, but of course this neglects the fact that there are clear period and correlated behaviors that modulate and provide direction to the random/sudden shifts that are observed.
What is needed is something of a synthesis of all of this. But that synthesis is not easy, because the Earth is a chaotic system, and small fluctuations today can cause the entire planet to follow a completely different path given the same intermediate forcings five or ten years from now. Or the opposite — some fluctuations are utterly ignorable because they DO average out and have little impact on long term trends. And I don’t think we even can identify which is which, let alone put the ones that matter to good predictive use.
rgb
Just a short note that the “pale yellow flower Dryas octopetella, an arctic wildflower typical of cold, open, Arctic environments” has an english name Mountain Aven.
it was meant as a comment on the thread Younger Dryas, my mistake
Stephen Wilde says:
June 19, 2012 at 12:20 pm
iii) hopefully one day acknowledge that average global atmospheric surface pressure has a bearing on the maximum sea surface temperatures that can be achieved before the convective response eliminates any further energy gains at the surface.
The maximum sea surface temperature is largely regulated by evaporation; a surface cooling process. Evaporation increases exponentially as water temperatures in the topics rise through the 80s and 90s (f). I have heard that the peek water temperatures in the oceans occur near Middle East and are near 100 degrees. T this point, evaporation does not allow the temperature to go higher, no matter what the air temperature and how much sunshine falls on the water.
Undoubtedly, this rapid evaporation is also fueling the tropical thunderstorms, which, in turn, augment the surface water temperature with a reduction in insolation, cooling rains and winds that produce upwelling.
I don’t see why average global atmospheric surface pressure would have a significant bearing on sea surface temperatures, as average surface pressure doesn’t vary all that much. I also don’t see how any of this impacts Mr. Eschenbach’s hypothesis. What goes on between the surface and the TOA is very important to understanding climate, but, if Willis is correct, not required to understand climate sensitivity to increasing CO2.