Are the world's glaciers in mortal danger?
Earth's average temperature has risen by about two-thirds of a Celsius degree in the past century. That doesn't sound like much, but glaciers are feeling the heat. Although some of these ice rivers seem to be holding their own, surveys suggest that most of the planet's glaciers are on the decline, many of them significantly. If global warming continues unabated, regardless of whether it's due primarily to natural cycles or human activity, many glaciers could literally melt out of existence.