Forces of Change
Based on satellite data collected since 1978 and analyzed by Julienne Stroeve, University of Colorado, CIRES, used courtesy of NSIDC.
Per decade, the loss in the extent of summer sea ice has equaled an area the size of Arizona.
Graph The M Factory © Smithsonian Institution.

Shrinking Sea Ice

Shrinking sea ice is one of the most worrisome changes in the Arctic.

The loss of sea ice is already affecting the region’s environment, wildlife, and cultures. In addition, shrinking sea ice may be an early sign of increased global temperatures: Sea ice is very sensitive to small changes in the air above it and in the water below it.

How Much Has Sea Ice Declined?

Satellite data show the extent of Arctic summer sea ice has shrunk 15-20% since 1979.  Submarine surveys show a loss in thickness of up to 40% in some areas in the past few decades.