Researchers at the University of Colorado at Boulder have found that the extent of Arctic sea ice, the floating mass of ice that covers the Arctic Ocean, is continuing its rapid decline. The latest satellite information indicates the September 2004 sea ice extent was 13.4 percent below average, a reduction in area nearly twice the size of Texas, said Mark Serreze of CU-Boulder’s National Snow and Ice Data Center, or NSIDC. The decline in sea ice extent during September has averaged about 8 percent over the past decade, said Serreze, who is part of a CU-Boulder team monitoring Arctic sea-ice conditions. “This is the third year in a row with extreme ice losses, pointing to an acceleration of the downward trend,” he said.
“While a ‘low’ September ice extent one year is often followed by a recovery the next year, this was not the case in 2003, which was about 12 percent below average,” Serreze said. The September 2004 sea-ice loss was especially evident in extreme northern Alaska and eastern Siberia. The CU-Boulder researchers used remote-sensing data from the SSMI satellite to record the sea-ice changes. One possible explanation for the continuing loss of sea ice is that climate warming from human activities like the burning of fossil fuels is becoming more apparent, said Serreze. “Climate models are in general agreement that one of the strongest signals of greenhouse warming will be a loss of Arctic sea ice,” he said. “Some indicate complete disappearance of the summer sea ice cover by 2070.”