Raymond, C.F. 2002. Ice sheets on the move. Science 298: 2147-2148.
What was done
The author, Charles F. Raymond of the Department of Earth and Space Sciences at the University of Washington in Seattle, presents his brief appraisal of the status of the world's major ice sheets.
What was learned
Raymond states that:
1. "Certain marginal areas of the Greenland Ice Sheet subject to melting show large changes," including "ice shelf disintegration, thinning, and flow acceleration," but "the interior remains in overall balance."
2. "There is little evidence that the huge East Antarctic Ice Sheet is responding to recent climate warming."
3. "Substantial melting on the upper surface of WAIS [the West Antarctic Ice Sheet] would occur only with considerable atmospheric warming."
4. Of the three major WAIS drainages, the ice streams that drain northward to the Amundsen Sea have accelerated, widened and thinned "over substantial distances back into the ice sheet," but "the eastward drainage toward the Weddell Sea is close to mass balance."
5. Of the westward drainage into the Ross Ice Shelf, "over the last few centuries, margins of active ice streams migrated inward and outward," while the "overall mass balance has changed from loss to gain," as "a currently active ice stream (Whillans) has slowed by about 20% over recent decades."
What it means
In what sounds pretty much like a summary statement that takes account of the above-mentioned phenomena, Raymond states that "the total mass of today's ice sheets is changing only slowly, and even with climate warming increases in snowfall should compensate for additional melting." Hence, if those words truly mean what they say, one can only conclude that increases in snowfall should compensate for whatever additional melting of earth's polar ice sheets might occur if the planet's temperature continues its post-Little Ice Age rebound.
Reviewed 5 February 2003