CO2 'highest for 650,000 years'

[Krell]

Current levels of the greenhouse gases carbon dioxide and methane in the atmosphere are higher now than at any time in the past 650,000 years.



That is the conclusion of new European studies looking at ice taken from 3km below the surface of Antarctica.

The scientists say their research shows present day warming to be exceptional.
Other research, also published in the journal Science, suggests that sea levels may be rising twice as fast now as in previous centuries.

Treasure dome
The evidence on atmospheric concentrations comes from an Antarctic region called Dome Concordia (Dome C).

"We found a very tight relationship between CO2 and temperature even before 420,000 years," said Professor Stocker.

"The fact that the relationship holds across the transition between climatic regimes is a very strong indication of the important role of CO2 in climate regulation."

Epica scientists will now try to extend their analysis further back in time.

Water rise
Another study reported in the same journal claims that for the last 150 years, sea levels have been rising twice as fast as in previous centuries.

Using data from tidal gauges and reviewing findings from many previous studies, US researchers have constructed a new sea level record covering the last 100 million years.
They calculate the present rate of rise at 2mm per year.

"The main thing that's changed since the 19th Century and the beginning of modern observation has been the widespread increase in fossil fuel use and more greenhouse gases," said Kenneth Miller from Rutgers University.
The Intergovernmental Panel on Climate Change, the body which collates scientific evidence for policymakers, concludes that sea level rose by 1-2mm per year over the last century, and will rise by a total of anything up to 88cm during the course of this century.

http://news.bbc.co.uk/1/hi/sci/tech/4467420.stm


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