Posted on 12/31/2013 7:29:24 AM PST by Abathar
Cloud impact on climate sensitivity unveiled
Global average temperatures will rise at least 4°C by 2100 and potentially more than 8°C by 2200 if carbon dioxide emissions are not reduced according to new research published in Nature. Scientists found global climate is more sensitive to carbon dioxide than most previous estimates.
The research also appears to solve one of the great unknowns of climate sensitivity, the role of cloud formation and whether this will have a positive or negative effect on global warming.
“Our research has shown climate models indicating a low temperature response to a doubling of carbon dioxide from preindustrial times are not reproducing the correct processes that lead to cloud formation," said lead author from the University of New South Wales’ Centre of Excellence for Climate System Science Prof Steven Sherwood.
“When the processes are correct in the climate models the level of climate sensitivity is far higher. Previously, estimates of the sensitivity of global temperature to a doubling of carbon dioxide ranged from 1.5°C to 5°C. This new research takes away the lower end of climate sensitivity estimates, meaning that global average temperatures will increase by 3°C to 5°C with a doubling of carbon dioxide."
The key to this narrower but much higher estimate can be found in the real world observations around the role of water vapour in cloud formation.
Observations show when water vapour is taken up by the atmosphere through evaporation, the updraughts can either rise to 15 km to form clouds that produce heavy rains or rise just a few kilometres before returning to the surface without forming rain clouds.
When updraughts rise only a few kilometres they reduce total cloud cover because they pull more vapour away from the higher cloud forming regions.
However water vapour is not pulled away from cloud forming regions when only deep 15km updraughts are present.
The researchers found climate models that show a low global temperature response to carbon dioxide do not include enough of this lower-level water vapour process. Instead they simulate nearly all updraughts as rising to 15 km and forming clouds.
When only the deeper updraughts are present in climate models, more clouds form and there is an increased reflection of sunlight. Consequently the global climate in these models becomes less sensitive in its response to atmospheric carbon dioxide.
However, real world observations show this behaviour is wrong.
When the processes in climate models are corrected to match the observations in the real world, the models produce cycles that take water vapour to a wider range of heights in the atmosphere, causing fewer clouds to form as the climate warms.
This increases the amount of sunlight and heat entering the atmosphere and, as a result, increases the sensitivity of our climate to carbon dioxide or any other perturbation.
The result is that when water vapour processes are correctly represented, the sensitivity of the climate to a doubling of carbon dioxide - which will occur in the next 50 years – means we can expect a temperature increase of at least 4°C by 2100.
“Climate sceptics like to criticize climate models for getting things wrong, and we are the first to admit they are not perfect, but what we are finding is that the mistakes are being made by those models which predict less warming, not those that predict more,” said Prof. Sherwood.
“Rises in global average temperatures of this magnitude will have profound impacts on the world and the economies of many countries if we don’t urgently start to curb our emissions.
note 2 things:
1-no comments allowed
2-their disclaimer at the bottom:
AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.
I really thought (incorrectly) that those who got Fs in physics went into politics.
Now I know that some of them manage to get into “climate research”.
These guys just keep digging don’t they??? They are claiming essentially an 8 to 10 degree F increase in temperatures….BWAHAHAHAHAHAHA. What they really ought to be concerned with is the cooling that is provably on going….but I won’t hold my breath for that
Jesus of Nazareth said, "And pray ye that your flight be not in the winter." (Mark 13:18)
Think he might've known something the Al Gores of the world don't? :-)
Beautiful! Actual results have not agreed with modeled predictions, so the solution is to create predictions at greater variance with actual results.
When does SCIENCE take offense at data?
1. Set alarmist goals that are far off(chronologically)
2. Collect grant money
3. See #1
More liberals sucking more money out of over-funded academia.
Move along folks...don’t feed the loons.
a classic
Global temperature has not risen in 16 years: http://www.politifact.com/rhode-island/statements/2013/aug/25/steve-goreham/global-warming-skeptic-says-global-surface-tempera/
Carbon dioxide has increased 7% in the atmosphere during that time: http://en.wikipedia.org/wiki/Carbon_dioxide_in_Earth%27s_atmosphere
The Antarctic ice cap is the biggest ever. The Arctic icecap is on the small side of its historical range. 2012 was very low but that was an anomaly. 2013 represents part of a modest recovery from the 2007 warm point. The Arctic temperatures have been steady since around 2007.
Gotta keep the research dollars flowing into their coffers.
The sky is falling for a different reason today.
No mention of solar cycles and how they affect cloud formation? I wonder why.
Prof. Sherwood = Prof. Surewon’t
Shouldn’t this be labeled/sarcasm?
In Minnesota we are being told that by Friday and Saturday our temps will rise to -—TaTa-— the teens. But by next Monday, we will have another cold blast which will be the coldest yet for the season.
We could use a bit of global warming right now. Can we sue these yokels if we don’t get it????
It's the grant money that won't die.
The clowns this UNSW professor calls colleagues are currently trapped in the ice.
5 year work history.
MULTIPLE references.
600+ question phsych evaluation.
Just so you can do paperwork on the paperwork for the paperwork that you just did paperwork on the valve handle you jiggled.
Has anyone noticed that never, ever, ever has there been a global warming alarmist who proposes free-market solutions to reducing carbon emissions? The only solutions I ever hear are higher taxes, more powerful government and movement toward to a global socialist command economy. Why is that?
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