Sensitive side (from the NASA Global Climate Change Website)
By Rosemary Sullivant,
NASA Jet Propulsion Laboratory
A little extra carbon dioxide in the air may, unfortunately, go further towards warming Earth than previously thought. A team of British and U.S. researchers have uncovered evidence [1] that Earth’s climate may be up to 50 percent more sensitive to long-term increases in atmospheric carbon dioxide than current climate models predict. The reason for the underestimation, they say, may be due to long-term changes in ice sheets and vegetation that are not well represented in today’s global climate models.Just how much will global temperature rise in response to increases in atmospheric carbon dioxide? This is one of the key questions that climate scientists need to answer. According to the climate models used in the most recent report from the Intergovernmental Panel on Climate Change (IPCC), doubling the amount of carbon dioxide in the atmosphere from pre-industrial levels is expected to warm Earth by about 3 degrees Celsius (5 degrees Fahrenheit), once the atmosphere and oceans spend a few years or decades adjusting and reaching a balance.
But according to a recent study by a team of researchers that includes Gavin Schmidt of NASA’s Goddard Institute for Space Studies, Earth’s climate is also influenced by other, much slower processes. These include changes in ice sheets, vegetation and aerosols, for example, that take place over hundreds and thousands of years.
Because of their complexity and long timescales, these processes are almost impossible to integrate into today’s climate computer models. As a result, it has been difficult to know just what their effect on Earth’s climate sensitivity would be.
To learn more about this sensitivity, Schmidt and his co-authors looked back 3 million years into Earth’s past. They used a computer model that describes the oceans and atmosphere to predict, retroactively, the climate of the mid-Pliocene — a period when both global temperatures and atmospheric carbon dioxide concentrations were higher than today. The model substantially underestimated just how high temperatures would go. When the researchers adapted the model to include the effects of long-term climate changes in vegetation and ice sheets, they were able to get a much closer representation of the warming in the Pliocene era.
The team found that it took much lower concentrations of atmospheric carbon dioxide to recreate the Pliocene’s warm climate than current models — which consider only the relatively fast-adjusting components of the climate — predict. Pliocene carbon dioxide levels are estimated to have been around 400 parts per million by volume (ppmv), while according to current simulations it would take 500 to 600 ppmv of carbon dioxide to bring about the warm temperatures of the Pliocene. As a result, the researchers estimate that Earth’s response to elevated concentrations of atmospheric carbon dioxide is 30 to 50 percent greater than previously calculated. In other words, the climate is more sensitive to carbon dioxide than we thought.
This higher sensitivity of the climate should be taken into account, the team concludes, when targets are set for limiting greenhouse gas emissions. The results of the study appear in Nature Geoscience.
Research paper: [1] Daniel J. Lunt et al., “Earth System Sensitivity Inferred from Pliocene Modelling and Data,” Nature Geoscience, Vol. 3, No. 1 (2010).
PDF Here
As usual, I highly doubt it’s “worse than we thought”, since it appears they “thought” a single molecule of CO2 is capable of heating the planet to 2 million K within nanoseconds. I would accept them discovering that their computer models are “worse than they thought”, though.
Of course, even assuming they’ve got everything else right, what kind of idiots think a single variable is the only driver? Yeah, that’s a moot question…
Quick, quick, more funding needed, millions of year’s research coming up!!!
Why can’t they provide a simple tutorial that shows how much heat is being generated by CO2 right now?
Once again, it’s worse than we thought.
Yet another eyeroller moment; it’s seems to be becoming a daily event.
Since the theory’s sound (everybody says so, even the reverend Al Gore!), there must be something wrong with the data or the model.
How about this thought — “It’s much warmer than our models predict – something beside CO2 must be driving up these temperatures.”
Frankly, it sounds like climate ‘science’ is maintaining itself at a level of understanding equal to a level achieved by our ancestors who were alive during the period this study covered.
I assume that as this was a joint British/US enterprise between “researchers”, then my taxes have partially funded this garbage. I demand my money back.
“more….than we thought”. It’s Always more/warmer/catastrophic. Would anyone expect those people – and Gavin Schmidt in particular – to conclude it was less ? Nothing to it, really. Just twiddle the right knobs on those computer games until it’s more .
I nominate “Worse than expected.” as the climate catchphrase of the new decade.
AGW-Skeptic99 says:
May 5, 2010 at 10:47 pm
Somebody has to say it is worse than we thought:)
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And robustly so
So CO2 doesn’t quite explain the climate of the Pliocene. I’m sorry, but it begs the question: doesn’t that imply that the other factors than CO2 seem more important than previously thought? No, they claim the opposite: CO2 is even more important!
This is beginning to look more like religious belief than science. They’re chanting “I believe in CO2, the Forcing almighty, Creator of Heat and Estimates. Amen”.
Well if NASA JPL thinks its effect is underestimated by 50% and Professor Jyrki Kauppinen of the University of Turku thinks its overestimated by 90-95% then we have something of a controversy.
As they say the science is clearly in, which is why I love science.
Prof. Kauppinen’s interview here:
http://www.ts.fi/online/kotimaa/124484.html
(I don’t read Finnish but this auto translation looks pretty clear:
Department of Physics, University of Turku study showed that carbon dioxide is a significantly smaller impact on global warming than previously thought. Results are based on, inter alia, spectrum analysis. Research led by Professor Jyrki Kauppinen according to increasing atmospheric carbon dioxide to explain only 5-10 percent of observed global warming .- The climate is warming yes, but not because of greenhouse gases, “says Kauppinen.)
Sorry, the computer models are not nearly accurate enough to distinguish between 400 and 500ppm CO2. If you tune a model to high CO2 sensitivity that’s all you will ever get. Gavin and Co. have got cause and effect the wrong way round here. Notice that they didn’t even mention water vapor (the main GHG). Generally it’s considered a function of air temperature but ice effects it too.
The paleo temperature history shows that the Earth has two states – warm when there is no ice at the poles and cool like now when there is. Temperature here really means the temperature of the deep ocean water. The reason is that ice is the great big albedo switch. Ice increases outgoing short wave radiation (reflected sunlight). It also lowers evaporation which reduces water vapor (the main GHG). Vegetation changes are secondary as they follow temperature and moisture. The presence or absence of ice is determined by the position of the continents. If there is ice at or near the poles as now then the Earth is cool. If warm ocean currents can get to the poles then any winter ice will melt in the summer, the dark polar oceans will absorb solar radiation and outgoing short wave radiation will be reduced. The oceans will then be warm. The transition between the two states (over a 3 million year period) takes a long time because of the thermal inertia of the ocean water.
CO2 has nothing to do with it. Henry’s law ensures that CO2 levels will be high when the oceans are warm and low when cold because of outgassing. So warm epocs have hight CO2 levels and cool epocs have low CO2 levels. The correlation between paleo CO2 and temperature is no good to say the least. We honestly don’t know whether temperatures are rising now because of human CO2 emissions or because the ocean water buried during the mediaeval warm period is coming to the surface and outgassing now.
If climatology was anything like a normal science it would be possible to discuss it amicably but we can’t. The government’s coin created then corrupted the science bureaucracies completely.
Ah yes…. still another computer model where GHGs are the only possible explanation and the climate is even more sensitive than we thought. I was programming when Gavin was still soiling his diapers and I’m not impressed. Lord above, just how much longer do we have to put up with this?
Inductive hindcasting is not, and never will be science.
This only makes sense if the assumption that CO2 is the forcing agent is correct. The historical evidence is not conclusive. And to go back so far in time …………..only to find a period that is crawling with planetary health. And identify it as a catastrophic occurrence seems a bit strange. Am I missing something?
‘Our Gav, what have you done I says’
‘What do you mean Stace’
‘Since the truth came out a few months ago I couldn’t go to the shops without people pointing their fingers and whispering,now you’ve really blown it. You and your mates have been telling us for ‘ears that we have a problem but now you tell us that there was more CO2 in the past and it was much warmer’
‘What’s wrong with that Stace’
‘Oh Gav, WHERE DID ALL THE CO2 COME FROM’?
The isthmus of panama formed about 3 to 3.5 million years ago. Don’t you think the resulting change in ocean circulation patterns (like the formation of the Gulf Stream!) might have produced a different climate pattern? What sort of sense does it make to use today’s climate models, which are tuned to the climate patterns produced by today’s ocean currents, to model climate 3 million years ago when the isthmus of panama was forming or had just formed?
I see the pic of the CO2 molecule at the start of this thread – I wonder what the little rods holding the carbon atom to the two oxygen atoms are made of? Must be made of something with very small atoms! Or is this just a way of depicting the molecular bonds?
R. Gates: “will need to really look into this”
No, every engineer will not even do that. Back of the envelope estimation shows they are 3 to 4 orders of magnitude off. Oh wait, that’s an exaggeration. As the admirable E.W.Dijkstra made clear in his famous
http://userweb.cs.utexas.edu/users/EWD/transcriptions/EWD10xx/EWD1036.html
we cannot think and compare well in OoM: “…worse than comparing, as a means of transportation, the supersonic jet plane with a crawling baby, for that speed ratio is only a thousand.” And now we have scientists who tell us that adding the speed of a crawling baby to that of a supersonic jet plane leads to consequences worse than we thought.
I still think masturbating for real is a lot more productive then doing it with incomplete, inadequate, assumption riddled, numeric models.
Why are these people who use computer modelling called ‘scientists’? Writing computer programs and running them is in the realm IT surely. We do science a diservice to say otherwise.
I am still waiting to see any climate model running backwards, which will be able to recreate the simple CET record. Then I will start considering it as somehow validated against the real world.
http://www.climate4you.com/CentralEnglandTemperatureSince1659.htm
Alas, all climate models produce just variations of hockey stick:
http://www.epa.gov/climatechange/science/images/ipcc_scenario_prediction.gif
Compare the models for Arctic with the 20th century reality, for example:
http://i43.tinypic.com/14ihncp.jpg
The isthmus of Panama formed in the Pliocene about 3.5 million years ago and there seems to be general agreement that this cooled down the earth significantly because this slowed down ocean circulation. This article seems to describe the period about 500000 years later, but that might have been just before the Greenland ice cap formed, so there may have been less cooling feedback from arctic ice at that point of time. There are so many factors here that I really doubt they can model them.
On the other hand, if they’re right, wouldn’t that be nice? A slow warming over thousands of years? Yes, thanks! Maybe we can avoid the next ice age!
No doubt the Gavin-proxy must have been one parameter in the model (the occurance of the name Gavin at different time periods as suggested by McIntyre)
Nature Magazine’s parent company Macmillan publishing has admitted guilt to bribery. They admitted paying to obtain educational book sales contracts in Sudan, according to the World Bank. BBC report. The World Bank was administering a trust fund for the text books, has put Macmillan on suspension temporarily from projects it funds. The point is, this reflects badly on the editorial practices of Nature, in my opinion. Nature was not mentioned in the BBC report. It’s interesting how the elite do business.
Looks like an exercise in force fitting to me to explain why their models can not replicate previous periods of time. Give me 4 parameters and I could do the same!
when you know the answer get back to us, meanwhile – GO AWAY!