Strong Negative Feedback from the Latest CERES Radiation Budget Measurements Over the Global Oceans
By Dr. Roy W. Spencer, Ph. D.
Arguably the single most important scientific issue – and unresolved question – in the global warming debate is climate sensitivity. Will increasing carbon dioxide cause warming that is so small that it can be safely ignored (low climate sensitivity)? Or will it cause a global warming Armageddon (high climate sensitivity)?
The answer depends upon the net radiative feedback: the rate at which the Earth loses extra radiant energy with warming. Climate sensitivity is mostly determined by changes in clouds and water vapor in response to the small, direct warming influence from (for instance) increasing carbon dioxide concentrations.
This can be estimated from global, satellite-based measurements of natural climate variations in (1) Earth’s radiation budget, and (2) tropospheric temperatures.
These estimates are mostly constrained by the availability of the first measurement: the best calibrated radiation budget data comes from the NASA CERES instruments, with data available for 9.5 years from the Terra satellite, and 7 years from the Aqua satellite. Both datasets now extend through September of 2009.
I’ve been slicing and dicing the data different ways, and here I will present 7 years of results for the global (60N to 60S) oceans from NASA’s Aqua satellite. The following plot shows 7 years of monthly variations in the Earth’s net radiation (reflected solar shortwave [SW] plus emitted infrared longwave [LW]) compared to similarly averaged tropospheric temperature from AMSU channel 5.
Simple linear regression yields a net feedback factor of 5.8 Watts per sq. meter per degree C. If this was the feedback operating with global warming, then it would amount to only 0.6 deg. C of human-caused warming by late in this century. (Use of sea surface temperatures instead of tropospheric temperatures yields a value of over 11).
Since we have already experienced 0.6 deg. C in the last 100 years, it would also mean that most of our current global warmth is natural, not anthropogenic.
But, as we show in our new paper (in press) in the Journal of Geophysical Research, these feedbacks can not be estimated through simple linear regression on satellite data, which will almost always result in an underestimate of the net feedback, and thus an overestimate of climate sensitivity.
Without going into the detailed justification, we have found that the most robust method for feedback estimation is to compute the month-to-month slopes (seen as the line segments in the above graph), and sort them from the largest 1-month temperature changes to the smallest (ignoring the distinction between warming and cooling).
The following plot shows, from left to right, the cumulative average line slope from the largest temperature changes to the smaller ones. This average is seen to be close to 10 for the largest month-to-month temperature changes, then settling to a value around 6 after averaging of many months together. (Note that the full period of record is not used: only monthly temperature changes greater than 0.03 deg. C were included. Also, it is mostly coincidence that the two methods give about the same value.)
A net feedback of 6 operating on the warming caused by a doubling of atmospheric CO2 late in this century would correspond to only about 0.5 deg. C of warming. This is well below the 3.0 deg. C best estimate of the IPCC, and even below the lower limit of 1.5 deg. C of warming that the IPCC claims to be 90% certain of.
How Does this Compare to the IPCC Climate Models?
In comparison, we find that none of the 17 IPCC climate models (those that have sufficient data to do the same calculations) exhibit this level of negative feedback when similar statistics are computed from output of either their 20th Century simulations, or their increasing-CO2 simulations. Those model-based values range from around 2 to a little over 4.
These results suggest that the sensitivity of the real climate system is less than that exhibited by ANY of the IPCC climate models. This will end up being a serious problem for global warming predictions. You see, while modelers claim that the models do a reasonably good job of reproducing the average behavior of the climate system, it isn’t the average behavior we are interested in. It is how the average behavior will CHANGE.
And the above results show that not one of the IPCC climate models behaves like the real climate system does when it comes to feedbacks during interannual climate variations…and feedbacks are what determine how serious manmade global warming will be.
I would note that Herr Dr. Professor Spencer does not seem to be a proponent of the flat earth theory.
Get your electric blankets folks!. Old Winter’s coming back:
As I watched in sorrow, there suddenly appeared
A figure gray and ghostly beneath a flowing beard
In times of deepest darkness, I’ve seen him dressed in black
Now my tapestry’s unravelling; he’s come to take me back
He’s come to take me back…♫♫♫
Dr. Spencer,
As a flight control systems engineer who deals with plant sensitivity to feedback loops all the time, I must applaud you for your contined work and focus on this issue. The systems I work on are nowhere near the levels of non-linearity nor the high level of multi-input, multi-output as is the earth’s climate. Yet I can find nothing inappropriate in your continued dyanmic analyses and focus on trying to determine the actual sensitivity of climate to CO2. Your work is very much appreciated by this engineer, and I always can comprehend each bit of analysis that you share with us. Well done!
Roy writes: Since we have already experienced 0.6 deg. C in the last 100 years, it would also mean that most of our current global warmth is natural, not anthropogenic.
How does he conclude that? During the last 100 years atmospheric GHGs have increased. The second part of the sentence does not follow from the first part, and it does not follow from the figure directly above. And the idea that the response will be linear is incorrect both from his figure and from future feedback affects. He mentions feedbacks in the following sentence but doesn’t clarify what those are. And I find it curious that the analysis is limited to 60S to 60N. Many of the feedbacks that enhance warming of the planet are found in the polar regions, so why ignore this crucial part of the planet when estimating future temperature response?
Will be good to read the paper to find out what he is saying since this blog post is very vague.
Feedback was always the big question that they thought (hoped) they had the answers to. Now it looks as if they’ve completely miscalculated. I wonder what they are going to put in the next IPCC assessment report. Everything seems to be going against them.
I imagine it’ll be like the orchestra on the sinking Titanic – they’ll just keep playing the music.
[REPLY – “God of mercy and compassion/Look with pity on my pain . . .” ~ Evan]
The evidence which refutes AGW continues to build.
Surely, there must be at least one scientifically literate government adviser in the US and UK who reads this and several other ‘science’ blogs. Cracks in the dam widen almost every day, but the likely unholy alliance of the Tories and the LibDems in the UK brings a new urgency to the situation.
In principle it could be possible to develop a useful climate model. However, in order for any model to be useful, it must be validated first – model predictions must agree with observations over and over again. This has not happened and climate models are therefore not useful (yet).
Without going into the detailed justification, we have found that the most robust method for feedback estimation is to compute the month-to-month slopes (seen as the line segments in the above graph), and sort them from the largest 1-month temperature changes to the smallest (ignoring the distinction between warming and cooling).
I’m going to have to pick on this for two points. First its “robust”. If you can pick on the warmists for claiming their models and analysis are “robust” you need to hold yourself to the same standard. The second point I’m going to pick on is the hand waving trick where you say this is the best method without explaining at all why it is the best method. And I use the word “you” not in the sense of a personal attack, but simply because I can’t come up with a better way to word my comments.
From an engineering perspective, the warmist’s assertion that the earth is going to hit a point and go into run away warming doesn’t hold water. If that were true, it would mean the earth’s climate has been in an unstable equilibrium for millions of years. Anybody who has ever balanced a rake on their hand should understand that an unstable equilibrium won’t last for very long even if you’re actively controlling said unstable equilibrium state.
Everybody. Read Dr Spencer’s book because he lays it on the line. I am relatively new to this climate catastrophe thing known as “Man-Made Global Warming” and “Settled Science”. Only got interested after Climategate; but since then I have been searching for a magic bullet indicator to tell if there is anything at all of value in the CO2 thermal forcing claims. Hmmmmm Arctic Ice? Just fine thank you. Antarctic? Same. Ocean temperatures? Dropping according to Argos; sea level rise ditto. Localized awful, awful droughts/floods/famines/four horsemen/you-name-it – either easily explained by natural phenomenon; accidents or lame leadership.
Warming? To me Dr Spencer’s explanation tells all: global warming as measured is a fraction of the modelers predictions and the entire Man-Made Global Warming meme as presented by Hansen/Gore/Mann/Jones/Briffa/Trenbeth et al is nothing but Piltdown Man writ large.
I wonder how Roy’s results compare to these empirical studies:
* Lorius 1990 examined Vostok ice core data and calculates a range of 3 to 4°C.
* Hoffert 1992 reconstructs two paleoclimate records (one colder, one warmer) to yield a range 1.4 to 3.2°C.
* Hansen 1993 looks at the last 20,000 years when the last ice age ended and empirically calculates a climate sensitivity of 3 ± 1°C.
* Gregory 2002 used observations of ocean heat uptake to calculate a minimum climate sensitivity of 1.5.
* Chylek 2007 examines the period from the Last Glacial Maximum to Holocene transition. They calculate a climate sensitivy range of 1.3°C and 2.3°C.
* Tung 2007 performs statistical analysis on 20th century temperature response to the solar cycle to calculate a range 2.3 to 4.1°C.
* Bender 2010 looks at the climate response to the 1991 Mount Pinatubo eruption to constrain climate sensitivity to 1.7 to 4.1°C.
How does he conclude that?
One crude and simple way would be to compare temperature increase from 1900 to 1950 and from 1950 to 2000. Nearly all of the CO2 increase occurred during the latter period.
The warming of the 20s-30s is quite similar in slope to that of the 80s – 90s.
There was also a strong warming after 1840. Lots of soot back then, but not so much CO2 by today’s standards.
There has been a massive percentage increase in CO2 for the last dozen years, yet temperature trend is down (even including the current el Nino).
One can conclude from this that CO2 may be a thumb on the scale, but it doesn’t appear to be a primary driver.
Perhaps this will ease the fears of the Kiwis:
AUCKLAND, New Zealand, May 6 /Medianet International-AsiaNet/ —
The Royal Australian and New Zealand Collage of Psychiatrists’ Congress at SkyCity Convention Centre in Auckland brings together mental health experts in a diverse range of areas. Here are some highlights from this morning’s program.
GLOBAL WARMING FEARS SEEN IN OBSESSIVE COMPULSIVE DISORDER PATIENTS
A recent study has found that global warming has impacted the nature of symptoms experienced by obsessive compulsive disorder patients. Climate change related obsessions and/or compulsions were identified in 28% of patients presenting with obsessive compulsive disorder…We found that many obsessive compulsive disorder patients were concerned about reducing their global footprint,” said study author Dr Mairwen Jones.
“Arguably the single most important scientific issue – and unresolved question – in the global warming debate is climate sensitivity”.
Well, we have a most convincing answer now, thank you very much for all the hard work.
But the propaganda war simply continues!
http://pgosselin.wordpress.com/2010/05/07/french-weather-event-proves-climate-change/
Where is it my “feedback”?, seems that Al Baby took it all just for him.
And I find it curious that the analysis is limited to 60S to 60N. Many of the feedbacks that enhance warming of the planet are found in the polar regions, so why ignore this crucial part of the planet when estimating future temperature response?
Well, surface data from outside those regions is mostly less than useless and even satellite data isn’t the best, seeing as how it’s a pole-to-pole orbit with sideways-looking sensors. Plus I think there are ice reflection issues that affect MW readings.
Can the IPCC get away with ignoring this paper too?
Wait, so this paper is making these conclusions from 7 years of data? That doesn’t seem like enough data to make that or any type of conclusion. Notice the 2 figures shown in this post start in 2002.
These results certainly seem more consistent with observed temp trends over the last 10 years vs the IPCC model predictions. Of course, the 0.5 C warming over the next century doesn’t account for any natural forcings over the same period – just the GHG forcing, right? Could end up being less or more, depending on how natural forcing feed in.
My goodness, a climate scientist actually gathering real world data, proposing a hypothesis, testing it and making conclusions based on real evidence rather than treemometers.
What next, publishing the data and the procedures so other climate scientists can duplicate the experiments?
How bizarre, how very, very bizarre.
Does the IPCC know of this witchcraft?
jeff brown says:
May 7, 2010 at 1:54 pm
“Roy writes: Since we have already experienced 0.6 deg. C in the last 100 years, it would also mean that most of our current global warmth is natural, not anthropogenic.”
Then jeff adds:
“How does he conclude that? During the last 100 years atmospheric GHGs have increased.”
So?
According to Occam’s Razor, the starting point is to simply assume a spurious correlation. Otherwise, we end up with science looking like this.
evanjones provides additional evidence that atmospheric CO2 is not the driver of the climate — much less the very tiny fraction that is anthropogenic CO2.
Contrary to the IPCC, it has consistently been my oft-stated position here that the climate sensitivity to anthropogenic CO2 is well below one, and probably less than 0.5. It would not surprise me at all if the sensitivity number was essentially zero, considering all the known and possibly unknown climate feedbacks that may be countering the radiative effect of CO2.
We will see who is right, Dr Spencer, or the IPCC. I’m betting on Dr Spencer.
Al Gore’s Weather (AGW) : ” it’s incredibly green, it’s amazing.”
This is too sensitive for Moi!
How can this be? Mah modellers failed.
“The pastoralists have just come out of eight years of drought and they’ve been hit with the best water in the area since 2000,” Mr Backway told The Times. “I haven’t seen so many grins on people’s faces in a long time. Driving up to the area … it’s incredibly green, it’s amazing.”
…-
“Sailing regatta to be held in the Australian desert”
” A “bone dry” salt lake surrounded by deserts in the middle of the Australian Outback is the last place you would expect to find a sailing regatta.
However a group of Outback sailing aficionados are planning to do just that when they hold the first regatta in the area around Lake Eyre, Australia’s largest – and driest – salt lake, since 1976.
Record rainfall and flooding in Queensland earlier this year has sent water streaming through many of Australia’s inland river systems, including Coopers Creek, which flows through two states into the Lake Eyre basin. ”
http://www.timesonline.co.uk/tol/news/world/article7119232.ece
Its dead Jim. As for evamjones, your measurements are constrained by the orbit of the satellite. In any case, the areas near the poles have a high albedo due to snow cover or ice cover most of the time. Clouds over Antarctica warm it since the clouds have a lower albedo than the snow cover does.
@Charles: One could say riding a motorcycle is also an example of this “unstable equilibrium” of which you speak; it is analagous to balancing a rake on your hand. I used to do a fair amount of motorcycle riding and was able to keep it enjoyably balanced until the gas gave out (the rake, not so much). However, tell me who or what has put earth’s climate on my motorcycle, or in a vertical position balanced on my hand? I realize this may be stretching it, but the analogy is appropriate. And maybe it is just a matter of semantics, but I don’t see how climate can be hoisted up this “unstable equilibrium” flagpole of yours. Can you supply a more conprehensive explanation?
But say climate was somehow elevated to a significantly higher energy state, from which it fell sometime in the future. Can you offer what constitutes this higher energy state? And should it somehow fall to a lower state, earth won’t warm up–it will cool off and the weather will settle down; the energy driving the climate will have been reduced. The ultimate end is an inhospitable, frozen earth (at least until the sun engulfs us, but that’s a long, long ways off).
But please, enlighten me if I’m wrong.
I agree with whoever said 7 years isn’t enough to be conclusive, even if it is almost twice as much as PIOMAS tries to use for ice volume, and AGWers seem to find it strangely compelling.
But if you read Roy’s latest book, it’s clear as he says that he’s not trying to *end* the AGW debate in scientific circles –he’s trying to get an open-minded debate *started* in those circles.
I doubt the 0.6C rise is even accurate considering the way measurements have been taken and changed over more than a century and how urban dimming effects were higher in the past than present. More like a 0.25C rise.