The artic ice cap may be melting much faster than previously thought, according to scientists from the National Oceanic and Atmospheric Administration (NOAA). The scientists tested 20 different climate change computer models for their ability to replicate the sea ice conditions that actually existed between 1979 and 1999. After discarding the models that couldn’t accurately replicate the actual data, they used the remaining models to predict the artic ice melt to 2050. They report that the arctic ice cap may shrink by more than 40% by 2050, even if atmospheric carbon dioxide levels remain where they are today. But it's more likely that carbon dioxide levels will continue to rise, given our appetite for fossil fuels. The original article is published in the September 8 issue of Geophysical Research Letters.
A major loss of arctic ice would be bad news not just for polar bears, but for marine ecosystems in general. The winners: oil and gas companies would be able to explore more of the arctic sea bed for new sources of oil and gas, and ships might be able to use northern shipping routes between the Atlantic and Pacific during the summer months.
Note added Sept. 28: The Oct. 1 issue of Time magazine has a cover story which discusses the political and economic implications of the loss of arctic ice due to global warming. Apparently, nations are rushing to lay claim to the land (and mineral resources) previously under the ice, and shipping companies are eagerly awaiting the time when the Northwest Passage is open, at least for some of the year.