Cooperative Institute for Research in Environmental Sciences

Melting Glaciers and Ice Sheets Contribute to Global Sea-Level Rise

The Steffen research group assesses the annual and interannual variability of cyrospheric parameters in the Arctic in response to climate perturbation. One example of our research projects - the Greenland ice sheet - is highlighted below.

The total volume of land-based ice in the Arctic has been estimated to be about 3,100,000 cubic kilometers, which corresponds to a sea-level equivalent of about eight meters. Most arctic glaciers and ice caps have been in decline since the early 1960s, with this trend speeding up in the 1990s. A small number of glaciers, especially in Scandinavia, have gained mass as increased precipitation outpaced the increase in melting in few areas.

The Greenland Ice Sheet dominates land ice in the Arctic. Maximum surface-melt area on the ice sheet increased on the average by 16% from 1979-2002 (Steffen et al., 2004), an area roughly the size of Sweden, with considerable variability from year to year, The total area of surface melt on the Greenland Ice Sheet broke all records in 2002, with extreme melting reaching up to 2000 meters in elevation. Satellite data show an increasing trend in the melt extent since 1979. This trend is interrupted in 1992, following the eruption of the Mt. Pinatubo, which created a short-term global cooling as particles spewed from the volcano reduced the amount of sunlight that reached the earth.

Seasonal surface melt extent on the Greenland Ice Sheet has been observed by satellite since 1979 and shows an increasing trend. The melt zone, where summer warmth turns snow and ice around the edges of the ice sheet into slush and ponds of meltwater, has been expanding inland and to record high elevations in recent years (source: Arctic Impacts of Arctic Warming, Cambridge Press, 2004).

Greenland
Weather Links
Photo Journal

In the News

September 2005
The Steffen Group reports on the maximum melt extent on the Greenland Ice Sheet for this year.

July 2005
The Steffen Group's latest field season is featured in this NOVA scienceNOW segment, which aired on PBS, July 26.

May 2005
The NASA-funded research of the Steffen Group is the subject of three BBC News reports:

May 19, 2005
mp4, 63 MB

May 20, 2005
mp4, 52 MB

May 20, 2005
mp3, 8 MB

April 2005
Konrad Steffen, his graduate students, and their fieldwork and research are featured in this New Yorker article on climate change research in the Arctic.

December 2002
From the CIRES Newsroom and the annual AGU fall meeting, see "Arctic Sea Ice Shrinking, Greenland Ice Sheet Melting."