How can so little warming cause so much melting?
Water can soak up a lot of heat. When the oceans get warmer, sea ice begins to melt in the Arctic and around Greenland. NASA's Earth satellites show us that every summer some Arctic ice melts and shrinks, getting smallest by September. Then, when winter comes, the ice grows again.
But, since 1979, the September ice has been getting smaller and smaller and thinner and thinner. Check out the Climate Time Machine and watch the ice shrink.
(Two images of Earth's Arctic area as described in caption.)
Earth's Arctic area: On left, the ice cap covers a large part of the Arctic Ocean. this image is an average of the ice extent during Septembers of 1979-1981. On right, however, a much smaller area is covered by ice in September 2007.
Ref:
NASA - Arctic Sea Ice Reaches Lowest Coverage for 2008.
Three sets of two images each, showing how glaciers have shrunk over time. Columbia Glacier from 1980 - 2005; Arapaho Glacier from 1898 to 2003; and Grinnell Glacier from 1940 - 2006.
See how much three glaciers have shrunk over time. Columbia Glacier from 1980 - 2005; Arapaho Glacier from 1898 to 2003; and Grinnell Glacier from 1940 - 2006.
Glaciers are another form of melting, shrinking ice. Glaciers are frozen rivers. They flow like rivers, only much slower. Lately, they have been speeding up. Many of them flow toward the ocean, then break off in chunks--sometimes huge chunks. In places such as Glacier National Park, the glaciers are melting and disappearing. The air is getting warmer, and less snow is falling during winter to renew the melted parts of the glaciers.