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Global warming much less serious than thought - new science ? The Register

Global warming much less serious than thought - new science
We're looking at just a couple of degrees with double CO2

By Lewis Page

Posted in Environment, 25th November 2011 11:07 GMT

Climate scientists funded by the US government have announced new research in which they have established that the various doomsday global warming scenarios are in fact extremely unlikely to occur, and that the scenarios considered likeliest - and used for planning by the world's governments - are overly pessimistic.

The new study improves upon previous results by including data from the remote past, rather than only examining records from recent times.

"Many previous climate sensitivity studies have looked at the past only from 1850 through today, and not fully integrated paleoclimate date, especially on a global scale," says Andreas Schmittner, professor at the College of Earth, Ocean, and Atmospheric Sciences at Oregon State uni.

"When you reconstruct sea and land surface temperatures from the peak of the last Ice Age 21,000 years ago – which is referred to as the Last Glacial Maximum – and compare it with climate model simulations of that period, you get a much different picture.

"If these paleoclimatic constraints apply to the future, as predicted by our model, the results imply less probability of extreme climatic change than previously thought," Schmittner adds.

The baseline assumption of climate science at the moment is that given a doubling of atmospheric CO2 compared to pre-industrial levels the most probable result is that the Earth would see a surface temperature rise average of 3°C - and that there would be a significant chance of much bigger, perhaps fatal rises.

Schmittner and his colleagues' analysis says that the planet's climate simply can't be this sensitive to CO2 changes, however, or much more extreme events should have occurred at certain points in the past - and they did not. For instance, if the climate were sensitive enough that doubled CO2 could mean catastrophic warming, the low carbon levels seen 21,000 years ago should have resulted in an equally lifeless iceball planet.

"Clearly, that didn't happen," Schmittner says. "Though the Earth then was covered by much more ice and snow than it is today, the ice sheets didn't extend beyond latitudes of about 40 degrees, and the tropics and subtropics were largely ice-free – except at high altitudes. These high-sensitivity models overestimate cooling."

According to the new improved analysis, the most probable result as and when double CO2 occurs is actually a rise of just 2.3°C - only just above the 2°C limit which international climate efforts are seeking to stay within. Plainly there's no great need to fear a rise above 450 parts per million (ppm) CO2, as people currently do - in fact there's no likely prospect of getting near a 2°C temperature rise for a century or more at present rates of CO2 increase (rising about about 2 ppm/year at the moment from a level of 390-odd). And Schmittner and his colleagues' results show a much tighter grouping of possible futures, too, so the scope for way-out doomsday scenarios is hugely reduced.

The Australian quotes [1] Schmittner as saying: "Now these very large changes (predicted for the coming decades) can be ruled out, and we have some room to breathe and time to figure out solutions to the problem."

The new study is published [2] in top-ranking boffinry journal Science. The research was funded by the US National Science Foundation. ®

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Climate Sensitivity Estimated from Temperature Reconstructions of the Last Glacial Maximum
 

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Did he cite this so called "new study"? I guess you're satisfied cause it's inline with your philosophy... Did you even bother to check what kind of other craps he writes? for instance: Exoplanet ranking suggests INTERSTELLAR WAR imminent ? The Register

Of course, if someone wrote it then it must be true, specially when you like it. Hey, what's a couple of degrees here and there anyway? Oh, what was your point again?
 

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Discussion Starter #4
Climate forecasts 'exaggerated': Science journal

Climate forecasts 'exaggerated': Science journal

by: Amos Aikman
From:The Australian
November 25, 20111:59PM

DRAMATIC forecasts of global warming resulting from a doubling of atmospheric carbon dioxide have been exaggerated, according to a peer-reviewed study by a team of international researchers.

In the study, published today in the leading journal Science, the researchers found that while rising levels of CO2 would cause climate change, the most severe predictions - some of which were adopted by the UN's peak climate body in its seminal 2007 report - had been significantly overstated.

The authors used a novel approach based on modelling the effects of reduced CO2 levels on climate, which they compared with proxy-records of conditions during the last glaciation, to infer the effects of doubling CO2 levels.

They concluded that current worst-case scenarios for global warming were exaggerated.

"Now these very large changes (predicted for the coming decades) can be ruled out, and we have some room to breathe and time to figure out solutions to the problem," the study's lead author, Andreas Schmittner, an associate professor at Oregon State University, said.

Scientists have struggled for many years to understand how to quantify "climate sensitivity" - how Earth will respond to projected increases in atmospheric carbon dioxide.

In 2007, the UN's peak climate body, the Intergovernmental Panel on Climate Change, warned that a doubling of CO2 from pre-industrial levels would warm the Earth's surface by an average of 2C to 4.5C, although some studies have claimed the impact could be 10C or higher.

Professor Schmittner said it had been very difficult to rule out these extreme "high-sensitivity" scenarios, which were very important for understanding risks associated with climate change.

The study found high-sensitivity models led to a "runaway effect" under which the Earth would have been covered in ice during the last glacial maximum, about 20,000 years ago, when CO2 levels were much lower.

"Clearly that didn't happen, and that's why we are pretty confident that these high climate sensitivities can be ruled out," he said.

Professor Schmittner said taking his results literally, the IPCC's average or "expected" value of a 3C average temperature increase for a doubling of CO2 ought to be regarded as an upper limit.

"Many previous climate-sensitivity studies have looked at the past only from 1850 through to today, and not fully integrated paleoclimate data, especially on a global scale," he said. "If these paleoclimatic constraints apply to the future, as predicted by our model, the results imply less probability of extreme climatic change than previously thought."

However, he cautioned that extreme climate change could still occur in some areas.

Dave Griggs, a professor of sustainability at Monash University, said that while models such as the one used by Professor Schmittner and his team were "the only tool we have" to assess long-term climate variability, they were also inherently imperfect.

"We are already heading towards a doubling of CO2 concentrations, so if we're going to get an equilibrium change of 3C that's actually pretty serious," Professor Griggs said.
 

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Discussion Starter #5
Climate Sensitivity Estimated from Temperature Reconstructions of the Last Glacial Ma

Climate Sensitivity Estimated from Temperature Reconstructions of the Last Glacial Maximum

Andreas Schmittner 1,*,
Nathan M. Urban 2,
Jeremy D. Shakun 3,
Natalie M. Mahowald 4,
Peter U. Clark 5,
Patrick J. Bartlein 6,
Alan C. Mix 1,
Antoni Rosell-Melé 7

+ Author Affiliations

1 College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331–5503, USA.

2 Woodrow Wilson School of Public and International Affairs, Princeton University, NJ 08544, USA.

3 Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138, USA.

4 Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY 14850, USA.

5 Department of Geosciences, Oregon State University, Corvallis, OR 97331, USA.

6 Department of Geography, University of Oregon, Eugene, OR 97403, USA.

7 ICREA and Institute of Environmental Science and Technology, Universitat Autònoma de Barcelona, Bellaterra, Spain.

Abstract

Assessing impacts of future anthropogenic carbon emissions is currently impeded by uncertainties in our knowledge of equilibrium climate sensitivity to atmospheric carbon dioxide doubling. Previous studies suggest 3 K as best estimate, 2 to 4.5 K as the 66% probability range, and nonzero probabilities for much higher values, the latter implying a small but significant chance of high-impact climate changes that would be difficult to avoid. Here, combining extensive sea and land surface temperature reconstructions from the Last Glacial Maximum with climate model simulations, we estimate a lower median (2.3 K) and reduced uncertainty (1.7 to 2.6 K 66% probability). Assuming paleoclimatic constraints apply to the future as predicted by our model, these results imply lower probability of imminent extreme climatic change than previously thought.
Received for publication 28 January 2011.
Accepted for publication 20 October 2011.
 

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Did he cite this so called "new study"? I guess you're satisfied cause it's inline with your philosophy... Did you even bother to check what kind of other craps he writes? for instance: Exoplanet ranking suggests INTERSTELLAR WAR imminent ? The Register

Of course, if someone wrote it then it must be true, specially when you like it. Hey, what's a couple of degrees here and there anyway? Oh, what was your point again?
It's not an OpEd.
 

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1. Climate change happens. Without it, this would still be an incandescent rock.

2. Governments can't legislate or tax #1 out of existance.

Wayne
Thanking his lucky stars that Katrina moved him to East Texas.
 

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I've thought for some time that the Al Gore style initiative was greatly overstating the case. They're predicting disaster within five to ten years, and as near as I can tell, we won't see serious changes for another 30 to 50 years, if fossil fuel consumption continues to increase at a linear or accelerated rate. Every hiccup in the weather is portrayed as human caused global warming, and eventually that will backfire when the weather's random nature turns against those arguments.

The trouble is: by the time the effects of human industrial activity do become obvious, correcting them will be much harder to do. So I do agree that taking steps now to increase efficiency and curtail fossil fuel consumption is a good thing to do. Not just for CO2, but a variety of reasons, not the least of which is the finite nature of fossil fuel, and the political instability around the largest sources.
 

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Arctic ice shelf collapse had historic precedence

The present collapse of the Arctic ice shelf and resultant affect on animal habitats may have a historical precedence according to research published at the Proceedings of the National Academy of Sciences web site on October 24, 2011.

An international team of geologists, biologists, and paleontologists studied ice core signatures in sediment cores from the Disraeli Fiord. Disraeli Fiord is considered to be a functional point in the study of Arctic ice changes due to its location.

The ice core analysis indicates that the Ward Hunt ice shelf formed no earlier than 4000 years ago. The ice shelf fractured 1400 years ago and began rebuilding 800 years ago. Present temperatures have reduced the ice shelf to a minimal size.
More here:

Arctic ice shelf collapse had historic precedence - National Paelenotology Science News | Examiner.com

The original study isn't available, so who can tell much more.
 
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