Facing The Heat

The Arctic ice cap is melting faster than scientists had expected and will shrink 40 percent by 2050 in most regions, with grim consequences for polar bears, walruses and other marine animals, according to government researchers. The Arctic sea ice will retreat hundreds of miles further from the coast of Alaska in the summer, the scientists at the National Oceanic and Atmospheric Administration (NOAA) concluded. That will open up vast waters for fishermen and give easier access to new areas for oil and gas exploration. It also likely will mean an upheaval in species, bringing new predators to warmer waters and endangering those that depend on ice.

The study, by NOAA oceanographer James Overland and meteorologist Muyin Wang, adds to the increasingly urgent predictions of major ice loss in the Arctic. Six years ago, the Intergovernmental Panel on Climate Change predicted major ice loss by 2100. An update by that United Nations-sponsored panel in February said that without drastic changes in greenhouse gas emissions, Arctic sea ice will “almost entirely” disappear by the end of the century. But Overland’s calculations are based largely on the carbon dioxide that already has been pumped into the atmosphere. That pollution will greatly diminish the ice by 2050 regardless of future curbs on emissions, he said on Thursday.

Overland and Wang compared 20 climate change computer models with actual satellite observations of Arctic ice cover. They discarded models that did not accurately track the ice cover for 20 years in the past, and extended the accurate models to predict the ice melt by 2050. The research was published in the journal Geophysical Research Letters.
(LAT-WP)