Data visualization of Arctic sea ice thickness, as measured by ICESat, shows the decline of the thickest ice (white, 4 to 5 meters thick) and increase in thinner ice (deep blue, 0 to 1 meter) from 2003 to 2008. Credit: NASA Goddard's Scientific Visualization Studio
Data visualization of Arctic sea ice thickness, as measured by ICESat, shows the decline of the thickest ice (white, 4 to 5 meters thick) and increase in thinner ice (deep blue, 0 to 1 meter) from 2003 to 2008. Credit: NASA Goddard's Scientific Visualization Studio

If current melting trends continue, the Arctic Ocean is likely to be free of summer sea ice by 2015, according to research presented at a conference organized by the National Space Institute at Technical University of Denmark, the Danish Meteorological Institute and the Greenland Climate Center. The estimates, which are consistent with some models presented at the American Geophysical Union meeting in 2007, are based on the rapid thinning (loss of volume) of Arctic sea ice, which has outpaced shrinkage in extent, in recent years. Last month NASA announced that overall Arctic sea ice thinned about 17.8 centimeters (7 inches) a year, for a total of 67 cm (2.2 feet) over the four winters from 2004 to 2008. …

Summer sea ice likely to disappear in the Arctic by 2015