Using data not available to the Intergovernmental Panel on Climate Change (IPCC), researchers from the U.S. Geological Survey, Columbia University and other institutions factored in faster-than-expected loss of sea ice, rising sea levels and a near-permanent drought developing in the American Southwest.
“It appears this has already begun,” the researchers told the annual meeting of the American Geophysical Union.
They pointed out that some projections of the impact of climate change issued by the IPCC in November 2007 have proven to be too conservative.
This is the case in the recent surge in melting of the Arctic ice cap and other frozen bodies of ice.
“We now have data on glaciers moving faster, ice shelves collapsing and other climate trends emerging that allow us to improve the accuracy of some of our future projections,” said lead author Peter Clark, a professor of geosciences at Oregon State University.
The "overarching" recommendation of the report (PDF 800k) is the need for committed and sustained monitoring of the forces that could trigger abrupt climate change, the researchers concluded.