A new study in Geophysical Research Letters ($ub. req'd), "Water-vapor climate feedback inferred from climate fluctuations, 2003-2008" analyzed recent variations in surface temperature and "the response of tropospheric water vapor to these variations." They concluded that the "water-vapor feedback implied by these observations is strongly positive" and "similar to that simulated by climate models." The analysis concludes:
The existence of a strong and positive water-vapor feedback means that projected business-as-usual greenhouse-gas emissions over the next century are virtually guaranteed to produce warming of several degrees Celsius. The only way that will not happen is if a strong, negative, and currently unknown feedback is discovered somewhere in our climate system.
A "warming of several degrees Celsius" = the end of life as we know it.
While some deniers/delayers/inactivists, like MIT's Richard Lindzen, have argued that negative feedbacks dominate the climate -- all of the evidence points to amplifying feedbacks dominating (except the one negative feedback that the deniers fiercely fight, discussed below).
That was a key point of this post: In the real world, key climate change impacts -- sea-ice loss, ice-sheet melting, desertification, and sea-level rise -- all are either near the top or actually in excess of their values as predicted by the IPCC's climate models. For a more recent detailed discussion of accelerating climate impacts and what that portends for the future on our current emissions path, see the new WWF report "Climate Change: faster, stronger, sooner [PDF]."
The major climate models are missing key amplifying feedbacks, some of which were discussed here.
And this all supports the analysis that the climate is much more sensitive to changes in greenhouse gas emissions and other "forcings" than the IPCC models have been saying and that a doubling of atmospheric concentrations of carbon dioxide from preindustrial levels to 550 ppm will ultimately warm the planet far more than 3°C, as NASA's James Hansen argues.
A number of major studies looking at paleoclimate data come to the same conclusion. Here are three:
- Scientists analyzed data from a major expedition to retrieve deep marine sediments beneath the Arctic to understand the Paleocene Eocene thermal maximum, a brief period some 55 million years ago of "widespread, extreme climatic warming that was associated with massive atmospheric greenhouse gas input." This 2006 study, published in Nature ($ub. req'd), found Artic temperatures almost beyond imagination -- above 23°C (74°F) -- temperatures more than 18°F warmer than current climate models had predicted when applied to this period. The three dozen authors conclude that existing climate models are missing crucial feedbacks that can significantly amplify polar warming.
- A second study, published in Geophysical Research Letters ($ub. req'd), looked at temperature and atmospheric changes during the Middle Ages. This 2006 study found that the effect of amplifying feedbacks in the climate system -- where global warming boosts atmospheric CO2 levels -- "will promote warming by an extra 15 percent to 78 percent on a century-scale" compared to typical estimates by the U.N.'s Intergovernmental Panel on Climate Change. The study notes these results may even be "conservative" because they ignore other greenhouse gases such as methane, whose levels will likely be boosted as temperatures warm.
- The third study, published in Geophysical Research Letters ($ub. req'd), looked at temperature and atmospheric changes during the past 400,000 years. This study found evidence for significant increases in both CO2 and methane (CH4) levels as temperatures rise. The conclusion: If our current climate models correctly accounted for such "missing feedbacks," then "we would be predicting a significantly greater increase in global warming than is currently forecast over the next century and beyond" -- as much as 1.5°C warmer this century alone.
Yes, natural negative feedbacks exist that would "eventually" absorb any excess carbon dioxide, but as one of the authors of a 2008 Nature Geosciences article explained, "not for hundreds of thousands of years" (see here).
Truly only one negative feedback in the planet's overall carbon cycle can act with sufficient speed and strength to avert catastrophic climate impacts: The dominant carbon-based life form on this planet will have to respond to the already painfully clear impacts of our carbon emissions by slashing those emissions sharply and eventually running the planet on carbon-negative power.
The time for this negative feedback is now.
This post was created for ClimateProgress.org, a project of the Center for American Progress Action Fund.
‘Copenhagen Diagnosis’ offers a grim update to the IPCC’s climate science
Comments
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Billhook Posted 5:26 am
28 Oct 2008
in the major option for carbon negative energy supplies,
namely reforestation as Coppice & Standards,
with charcoal/carbon sequestration (raising farm yields)
and with the provision of the full spectrum of fuels
incl. raw solid, refined solid, crude gaseous, refined gaseous,
primary liquid, and fabricated liquid, plus electricity.
Without the environmental lobby's input this option could of course be done so badly
as to be counter-productive -
yet it serves no potent commercial interests, so without that input
this evidently vital option may well continue to languish.
Hoping that Gristers may be awakening to the need -
Regards,
Bilhook
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moehrlei Posted 6:10 am
28 Oct 2008
As I watched it, I felt like the soldier in 'Saving Private Ryan' who is slowly stabbed to death while watching/struggling with the killer. The indescribable stupidity of it all leaves me without words.
Thanks for your good work.
No individual raindrop ever considers itself responsible for the flood.
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Pangolin Posted 6:44 am
28 Oct 2008
The forests of Europe have had centuries of shaping or they simply would not exist. The kind of mad, anything grows anywhere, groves I can find a short bike ride from here in California aren't likely in England or France.
Try to explain to a people focused on quarterly profits a business where one tries to limit net harvests to soil incomes; I wouldn't know how to do it. Explain to Wall Street that the berries bring birds and the birds bring soil. Good luck.
In the US labor doesn't have the rights and the land is clearcut.
Put the Carbon Back
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Ed Gulachenski Posted 9:59 am
29 Oct 2008
First the proof that a strong negative feedback exists which is cancelling out the positive feedback.
Satellite temperature data gathered over the last 30 years show no difference in temperatures changes in the troposphere as compared to surface temperatures. This is a significant finding since the troposphere should show changes some two to three times that on the surface. This is a fundamental characteristic of green house gas theory. All 22 models used by IPCC to predict future temperature rises, show this results, but actual measurements do not. The reason is that the IPCC models cannot represent clouds properly and hence do not take into account a large negative feedback that is taking place.
http://www.heartland.org/Article.cfm?artId=22604
What is this negative feedback?
Professor Richard Lindzen, The Alfred P Sloan Professor of Atmospheric Science at MIT has pointed out this deficiency in the models back in the 80s http://earthobservatory.nasa.gov/Study/Iris/
He concluded : "This is a terrifically important feedback, "because if you double the amount of carbon dioxide in the atmosphere but don't have any feedback within the system, you only get about 1 degree of warming (averaged over the entire globe). But climate models predict a much greater global warming because of the positive feedback of water vapor. Yet these models are missing potentially another negative feedback (the infrared iris) which can be anywhere between a fraction of a degree and 1 degree--the same order of magnitude as the warming." (The net result would then be that the Iris' negative feedback cancels the water vapor's positive feedback. The warming for a doubling of carbon dioxide would then return to the 1°C that scientists predict would occur if there were no feedbacks.)
This paper was not received very well as you might imagine from the anthropogenic global warming crowd. However the findings were verified by Roy Spencer last year in a peer reviewed paper: http://www.weatherquestions.com/Roy-Spencer-on-global-war ... Roy Spencer builds a very convincing case for this conclusion: "I believe that it is the inadequate handling of precipitation systems -- specifically, how they adjust atmospheric moisture contents during changes in temperature -- that is the reason for climate model predictions of excessive warming from increasing greenhouse gas emissions. To believe otherwise is to have faith that climate models are sufficiently advanced to contain all of the important processes that control the Earth's natural greenhouse effect.".
I am not a climate change scientists but I can read,I can reason and I have guestions on global warming that are not being answered.
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