The Search for a Short Term Marker of Long Term Climate Sensitivity
By Dr. Roy Spencer. October 4th, 2009
[This is an update on research progress we have made into determining just how sensitive the climate system is to increasing atmospheric greenhouse gas concentrations.]
While published studies are beginning to suggest that net feedbacks in the climate system could be negative for year-to-year variations (e.g., our 2007 paper, and the new study by Lindzen and Choi, 2009), there remains the question of whether the same can be said of long-term climate sensitivity (and therefore, of the strength of future global warming).
Even if we find observational evidence of an insensitive climate system for year-to-year fluctuations in the climate system, it could be that the system’s long term response to more carbon dioxide is very sensitive. I’m not saying I believe that is the case – I don’t – but it is possible. This question of a potentially large difference in short-term and long-term responses of the climate system has been bothering me for many months.
Significantly, as far as I know, the climate modelers have not yet demonstrated that there is any short-term behavior in their models which is also a good predictor of how much global warming those models project for our future. It needs to be something we can measure, something we can test with real observations. Just because all of the models behave more-or-less like the real climate system does not mean the range of warming they produce encompasses the truth.
For instance, computing feedback parameters (a measure of how much the radiative balance of the Earth changes in response to a temperature change) would be the most obvious test. But I’ve diagnosed feedback parameters from 7- to 10-year subsets of the models’ long-term global warming simulations, and they have virtually no correlation with those models known long-term feedbacks. (I am quite sure I know the reason for this…which is the subject of our JGR paper now being revised…I just don’t know a good way around it).
But I refuse to give up searching. This is because the most important feedbacks in the climate system – clouds and water vapor – have inherently short time scales…minutes for individual clouds, to days or weeks for large regional cloud systems and changes in free-tropospheric water vapor. So, I still believe that there MUST be one or more short term “markers” of long term climate sensitivity.
Well, this past week I think I finally found one. I’m going to be a little evasive about exactly what that marker is because, in this case, the finding is too important to give away to another researcher who will beat me to publishing it (insert smiley here).
What I will say is that the marker ‘index’ is related to how the climate models behave during sudden warming events and the cooling that follows them. In the IPCC climate models, these warming/cooling events typically have time scales of several months, and are self-generated as ‘natural variability’ within the models. (I’m not concerned that I’ve given it away, since the marker is not obvious…as my associate Danny Braswell asked, “What made you think of that?”)
The following plot shows how this ‘mystery index’ is related to the net feedback parameters diagnosed in those 18 climate models by Forster and Taylor (2006). As can be seen, it explains 50% of the variance among the different models. The best I have been able to do up to this point is less than 10% explained variance, which for a sample size of 18 models might as well be zero.
Also plotted is the range of values of this index from 9 years of CERES satellite measurements computed in the same manner as with the models’ output. As can be seen, the satellite data support lower climate sensitivity (larger feedback parameter) than any of the climate models…but not nearly as low as the 6 Watts per sq. meter per degree found for tropical climate variations by us and others.
For a doubling of atmospheric carbon dioxide, the satellite measurements would correspond to about 1.6 to 2.0 deg. C of warming, compared to the 18 IPCC models’ range shown, which corresponds to warming of from about 2.0 to 4.2 deg. C.
The relatively short length of record of our best satellite data (9 years) appears to be the limiting factor in this analysis. The model results shown in the above figure come from 50 years of output from each of the 18 models, while the satellite range of results comes from only 9 years of CERES data (March 2000 through December 2008). The index needs to be computed from as many strong warming events as can be found, because the marker only emerges when a number of them are averaged together.
Despite this drawback, the finding of this short-term marker of long-term climate sensitivity is at least a step in the right direction. I will post progress on this issue as the evidence unfolds. Hopefully, more robust markers can be found that show even a stronger relationship to long-term warming in the models, and which will produce greater confidence when tested with relatively short periods of satellite data.
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Since 1979, the “polar orbit” satellites have given us the capability (somewhat) for mapping the polar ice areas, although a fixed orbit crossing both poles isn’t too practical, so their are some blind spots in the coverage.
But when somebody starts trumpeting ICE THICKNESS well I smell a rat. There’s that teee core drilling problem again.
All the under sea ice filming i have ever seen shows wild bottom surface topology of the floating arctic ice, which is clearly realted to the top suface variability and the thickness. So immdeiately we have a problem of SAMPLING INTEGRITY.
A hand full of holes bored by some crazy north pole would be treckers do not make a good map of arctic ice volume. Now there have been some airborne scans that have yielded more data, but even those don’t come close to adeqate sampling of the arctic ocean total ice volume.
So I’ll take a pinch of salt with those ice volume numbers and trends, if you don’t mind; and as I already said; that is more a measure of how long some particular natural variability state has persisted.
And here at WUWT we are well in tune with climate/weather differences; which is why we don’t see evidence that climate is killing polar bears, although we’ve seen some weather do that; and the historic record is that polar bears have survived climate calamities much worse, than the 1979-2009 sea ice area changes; which don’t seem that remarkable at all.
Fred Lightfoot (09:44:25) :
“I have given up on the BBC, RT gives you the world news without the BS”
Now that is really strange! The Russians giving objective news while the west produces propaganda.
The world has turned upside-down.
Like everyone RR Kampen stops his hypothesis of the ice-age cycling just before the onset of cooling because the strong feedback theory requires a massive CO2 sink to appear out of nowhere. Just once i’d like someone to make a stab at describing the start of an ice age when this supposedly super-powerful heating agents are at their maximum extent. To AGWers half a theory is better than none it seems. [ok there is one lonely seismic event theory which I confess I dismiss].
Michael wrote:
“The President’s science czar John P. Holdren should be fired for incompetence and failing to inform the President that the Earth has been getting colder.”
Actually he should be fired for his support of mandatory population control laws. http://tinyurl.com/mo5ssu
“The President’s science czar is making Obama look like a dope and a buffoon.”
In all fairness, he doesn’t require any help.
I wonder what he is looking at? If the short term feedback is negative I don’t see a mechanism by which long term feedback can produce a net effect larger than the radiation effect was to begin with; so how can we get a greater than 1C Rise?
Am I wrong? If the feedback effect is negative don’t we get limited by thermodynamics to a maximum rise for a doubling of CO2 of about 1 C?
RR Kampen,
You like to talk about ice thickness now that ice extent is increasing. Well, maybe you’re right, maybe ice is getting thinner at the same time it is growing in extent. But, you then imply that this is somehow unprecendent, and portends to a great catastrophic global heating that is now unfolding. I don’t know if you’re right or not, but I can’t help but question that sea ice isn’t just doing what it has been doing for millenia – thickening and thinning, expanding and contracting. I don’t see any evidence that we are living in unprecendent times – other than in the explosion of hysteria, that is.
“First temperature rises due to long term Milankovitch (and such) effects. Vegetation and sea start releasing CO2 with a lag. This CO2 immediately helps to rise the temperature. ”
Eh, I have a question. If this CO2 IMMEDIATELY raises temperature, then please explain why there is an 800 year delay until CO2 levels start to climb?
Fred Lightfoot … was that Russian trucks in Canada (magnetic north pole)?
tallbloke (01:30:31) :
“It could be to do with atmospheric circulation, atmospheric angular momentum anyone?”
Something like that: My bet is on “length of the day”.
Doug in Seattle (09:57:15) :
“Now that is really strange! The Russians giving objective news while the west produces propaganda.
The world has turned upside-down.”
True, indeed!
The general opinion of the Russians is that climate change is natural and now entering a general cooling phase due to oceanic currents/solar influences.
I’m not sure what the Western experts’ opinions on the Russian scientists’ research is, but I’m sure it would be interesting if Khabibullo Abdusamatov would discuss his views on the matter here on WUWT.
Goreacle Report: What’s a “willies”?
…-
“Lawrence Solomon: The end is near
The media, polls and even scientists suggest the global warming scare is all over but the shouting
The great global warming scare is over — it is well past its peak, very much a spent force, sputtering in fits and starts to a whimpering end. You may not know this yet. Or rather, you may know it but don’t want to acknowledge it until every one else does, and that won’t happen until the press, much of which also knows it, formally acknowledges it.
I know that the global warming scare is over but for the shouting because that’s what the polls show, at least those in the U.S., where unlike Canada the public is polled extensively on global warming. Most Americans don’t blame humans for climate change — they consider global warming to be a natural phenomenon. Even when the polls showed the public believed man was responsible for global warming, the public didn’t take the scare seriously. When asked to rank global warming’s importance compared to numerous other concerns — unemployment, trade, health care, poverty, crime, and education among them — global warming came in dead last. Fewer than 1% chose global warming as scare-worthy.
The informed members of the media read those polls and know the global warming scare is over, too. Andrew Revkin, The New York Times reporter entrusted with the global warming scare beat, has for months lamented “the public’s waning interest in global warming.” His colleague at The Washington Post, Andrew Freedman, does his best to revive public fear, and to get politicians to act, by urging experts to up their hype so that the press will have scarier material to run with.
The experts do their best to give us the willies. This week they offered up plagues of locusts in China and a warning that the 2016 Olympics “could be the last for mankind” because “the earth has passed the point of no return.” But the press has also begun to tire of Armageddon All-The-Time, and (I believe) to position itself for its inevitable attack on the doomsters.” (More)
http://network.nationalpost.com/np/blogs/fpcomment/archive/2009/10/03/lawrence-solomon-the-end-is-near.aspx
What makes a climate trend?
The answer seems to be
Is 30 years a trend? It is when we try to claim AGW? How about 30 years of warming, and then 10 years of not warming? Does it have to not warm or cool for 30 years to balance that out?
The answer is never in the trend. The answer is in what is actually causing the observed climate. A good question is why isn’t the 10-year trend following the climate models? Another good question is how reliable is the data used to claim the 30-year warming trend?
[Sorry, I forgot the close my blockquote. I preview before posting would be helpful. Still, sorry about the oversight.]
[Reply: WordPress doesn’t provide a preview capability. ~dbs, mod.]
Truth is what works. – William James
If Dr. Spencer has an insight into things that they predict the future more accurately, I congratulate him. What we do know is that the current IPCC models do not work well at all. I am sure his stuff will not be the last word. In science, nobody does except nature.
“If you want to discuss models, that’s fine and OK by me. Otherwise cease, since we don’t allow religious discussions on WUWT. Read the policy page, the link under the masthead.” – A
Amen!
oops
Why is it that the reported warming since the 1930s is accepted as real? It certainly does not show up in the American data. And given the fact that Anthony’s weather station audit revealed a number of serious issues and the fact that CRU claims that there is no raw global data set I see no reason to accept the Global Temperature graph as an accurate representation of anything meaningful.
Remembering Dr. Spencer’s past work and current position, I would hazard a guess that the index is a ratio of the rate of change of the anomoly of radiation to the rate of change of the temperature anomoly.
That is, the index is a measure of how quickly more radiation results from a sudden change in temperature.
Dr. Spencer gave a hint in that he mentions that climate models are sluggish in reacting to temperature changes, and given the nature of his work, I would assume that he referring to a reaction in the amount of SW & LW rejected (observed by AQUA).
Apparently, when a temperature anomaly starts to build, nature changes the amount of SW & LW radiation from Earth rather quickly, whereas climate models are slower to react. Perhaps the slower a model is to react to such changes, the more warming it will predict in the long term.
My guess
Mens News Daily
Climate Data: Top Secret
http://mensnewsdaily.com/2009/10/03/climate-data-top-secret/
In the study noted below, the authors confirmed that the Arctic
warmed during the 1970–2008 period by a factor of two to
three faster than the global mean in agreement with model
predictions but the reasons was not be entirely anthropogenic
Here is what they said:
Understanding Arctic temperature variability is essential
for assessing possible future melting of the Greenland ice
sheet, Arctic sea ice and Arctic permafrost. Temperature trend
reversals in 1940 and 1970 separate two Arctic warming
periods (1910–1940 and 1970–2008) by a significant 1940–
1970 cooling period. Analyzing temperature records of the
Arctic meteorological stations we find that (a) the Arctic
amplification (ratio of the Arctic to global temperature trends)
is not a constant but varies in time on a multi-decadal time
scale, (b) the Arctic warming from 1910–1940 proceeded
at a significantly faster rate than the current 1970–2008
warming, and (c) the Arctic temperature changes are highly
correlated with the Atlantic Multi-decadal Oscillation
(AMO) suggesting the Atlantic Ocean thermohaline
circulation is linked to the Arctic temperature variability on
a multi-decadal time scale.
In my judgement our research would be better focused on cofirming the impact of known natural variables affecting our climate [like AMO,NAO , ENSO/PDO, ETC] than on the impact of the nebulous carbon dioxide . We keep jumping from one lily pad[someone’s unproven and undeveloped idea ] to another lily pad instead of seriously blogging what we already know to be valid areas of study based firm data. We are scattering our focus too much
http://www.lanl.gov/source/orgs/ees/ees14/pdfs/09Chlylek.pdf
climate audit is being flooded again maybe WUWT can post here?
Why 30 years?
Earths climate has large natural oscillations that are well known to last more than 10 years. PDO, IPO, I’m not sure what else (I’m a novice.)
Mr. Alex (10:47:16) :
BTW: Russia to sell natural gas to the US:
http://english.pravda.ru/business/companies/05-10-2009/109673-gazprom-0
OnT, but I like the mystery aspect, here. Yes, Leif, you’re right, it ain’t really science, but science has been knocked into a cocked hat, lately, so what the heck?
I considered a large range of possible short-term-to-long-term woo-woo indicators: Earth-Lunar distance, Lunar surface temperatures, annual UFO count, total atmospheric water content, polar bear population, optical density, surface & sub-surface sea temperatures, and so forth. In a way, since this is all supposed to devolve around GCM’s, I feel like I’m participating on a moot debate about how many angels can dance the kazatsky on a PhD’s pate.
So (assuming this conceptual “marker” isn’t a total will-o’-the-wisp) I’ll go with the ratio between rates of rise and fall of either temperature OR optical density, associated with a sudden warming event.
Vincent,
And since it does appear that CO2 does lag, where are the positive feedbacks triggered by CO2?
How is it that in the past CO2 has risen and not triggered the AGW predictions of tipping points?
It seems very clear that the AGW theories do not hold up well.
AGW does not correctly describe how greenhouse gasses work in the climate.
Peter Taylor (04:20:34) :
Nice post. It made me wonder if you ever get together with fellow Brit and WUWT poster Stephen Wilde to discuss this over a pint.
If so, I’d like to listen in next time I’m across the pond. I’m buying. Cheers.
Vincent
CO2 increases in the past did not trigger tipping points because the increase in CO2 took place very gradually over hundreds of years. Man has has CO2 levels more in 50 years than nature had done so in 1000 years. So far the climate is just beginning to catch up with that rapid increase and that’s why temp is predicted to go up significantly over the next 100 years. Nothing you’ve pointed out indicates any flaw in what the models predict.
Thanks
William
You would think Real Climate would have something new to say.
Do they think by keeping quiet it will make it go away?