Climate Scientists Issue Dire Warning

[Guest guest]

http://www.truthout.org/issues_06/022806EA.shtml

 

Climate Scientists Issue Dire Warning

By David Adam

The Guardian UK

 

Tuesday 28 February 2006

 

The Earth's temperature could rise under the impact of global

warming to levels far higher than previously predicted, according to

the United Nations' team of climate experts.

 

A draft of the next influential Intergovernmental Panel on Climate

Change (IPCC) report will tell politicians that scientists are now

unable to place a reliable upper limit on how quickly the atmosphere

will warm as carbon dioxide levels increase. The report draws together

research over the past five years and will be presented to national

governments in April and made public next year. It raises the

possibility of the Earth's temperature rising well above the ceiling

quoted in earlier accounts.

 

Such an outcome would have severe consequences, such as the

collapse of the Greenland ice sheet and disruption of the Gulf Stream

ocean current.

 

The shift in position comes as Tony Blair is expected to pledge

today to work towards a date for stabilising international greenhouse

gas emissions when he meets Stop Climate Chaos, the climate change

equivalent of Make Poverty History. The group is campaigning for a

target date of 2015 for stabilisation, saying a later date would

endanger the planet.

 

The new IPCC report will underpin international talks on how to

cut greenhouse gas emissions when the first phase of the Kyoto

protocol expires in 2012.

 

Set up in 1988 by the UN, the IPCC brings together hundreds of

experts to summarise the state of climate science for policymakers. It

has produced three reports since 1990, each of which has been

instrumental in establishing national and international strategies to

address global warming. Government officials have until June to

comment on the new draft, when scientists will gather in Bergen,

Norway, to produce a final version.

 

The IPCC's removal of the upper temperature estimation is posited

on new predictions about how the atmosphere would react to the carbon

blanket wrapped around it. The three previous reports assumed that a

doubling of carbon dioxide in the atmosphere would increase average

global temperature by between 1.5 and 4.5C. Since then, computer

models have foreseen increases as high as 11C, and some scientists

wanted the naturally conservative IPCC to raise the upper end of the

range. Others said such a move would be increase would be misleading

and alarmist.

 

According to sources who have seen it, the draft now assumes a

doubling of carbon dioxide would cause a likely temperature rise of

between 2 and 4.5C, but says higher increases are possible.

 

The shift follows several high profile studies convincing some

scientists the atmosphere may be much more sensitive to greenhouse

gases than they had thought. Peter Cox, a leading climate expert at

the Centre for Ecology and Hydrology in Winfrith, Dorset, said: " The

scientific agenda has moved from improving the predictions to thinking

about what are the chances of something awful happening. "

 

Dr Cox said the IPCC's move is significant because it will force

governments to seriously consider extreme scenarios that are unlikely

but potentially devastating. " The most probable thing is not the most

important thing to worry about. The upper end is where the big

problems are, because the impact rises as the temperature does. "

 

If we continue to burn fossil fuels at current rates, levels of

carbon dioxide in the atmosphere will reach 550 ppm (parts per

million) - double pre-industrial levels - by around 2050. The most

recent IPCC report, published in 2001, said this would increase global

temperatures by between 1.4 and 5.8C by 2100, and that sea levels

would rise by between 0.09 and 0.88 metres.

 

Climate scientists remain divided about the likelihood of the

worst-case scenario being realised. James Annan, a British climate

scientist who works on the Japanese Earth simulator supercomputer in

Yokohama, says the risks of extreme climate sensitivity and

catastrophic consequences have been overstated. He is about to publish

a study showing that the chance of climate sensitivity exceeding 4.5C

is less than 5%. He said: " It seems to me that some people seem to be

talking up the possibility of disaster in order to scare people into

doing something. "

 

Dave Stainforth, a climate modeller at Oxford University, said:

" This is something of a hot topic but it comes down to what you think

is a small chance - even if there's just a half per cent chance of

destruction of society, I would class that as a very big risk. "

 

The IPCC findings mirror a British report on avoiding dangerous

climate change published last month, in which Mr Blair admitted that

the risks may be more serious than previously thought. It included a

warning from Chris Rapley, head of the British Antarctic Survey, that

the huge west Antarctic ice sheet may be starting to disintegrate, an

event that would raise sea levels around the world by five metres.

" The last IPCC report characterised Antarctica as a slumbering giant

in terms of climate change, " he said. " I would say it is now an

awakened giant. There is real concern. "

 

-------