In Alaska, global warming has caused the Columbia Glacier to retreat more than 7 miles in the last 20 years, leaving calves of ice in Prince William Sound.
In Alaska, global warming has caused the Columbia Glacier to retreat more than 7 miles in the last 20 years, leaving calves of ice in Prince William Sound. Seth Borenstein/MCT
In Alaska, global warming has caused the Columbia Glacier to retreat more than 7 miles in the last 20 years, leaving calves of ice in Prince William Sound. Seth Borenstein/MCT

In a first step, nations pledge to fix global warming

February 01, 2010 5:52 PM