Arctic sea ice is melting three times faster than many scientists project, US researchers have reported, just days ahead of the next major international report on climate change.
Scientists at the National Center for Atmospheric Research and the University of Colorado in Boulder concluded on Monday that Arctic sea ice has declined at an average rate of about 7.8 per cent per decade between 1953 and 2006.
By contrast, 18 computer models used by the Intergovernmental Panel on Climate Change, a UN-sponsored climate research group, estimated an average rate of decline of 2.5 per cent per decade over the same period, the researchers said.
International delegates are meeting in Bangkok, Thailand, this week to hammer out the final wording of the third IPCC report.
Both the observations cited in the new study and projections from the IPCC computer models are for September, when Arctic sea ice is typically at its low point for the year.
For March, when the ice is typically at its most extensive, the new study found the rate of decline was 1.8 per cent per decade, about three times larger than the mean from the computer models.
The researchers said their observations indicate the retreat of summertime Arctic sea ice is about 30 years ahead of the pace projected by climate models.
{{/usCountry}}The researchers said their observations indicate the retreat of summertime Arctic sea ice is about 30 years ahead of the pace projected by climate models.
{{/usCountry}}The study, "Arctic Sea Ice Decline: Faster Than Forecast," will appear in the online edition of Geophysical Research Letters today, three days before the IPCC issues its report.