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The Greenland Ice Sheet and Sea Level Rise of the Last Interglacial
Cuffey, K.M. and Marshall, S.J.  2000.  Substantial contribution to sea-level rise during the last interglacial from the Greenland ice sheet.  Nature 404: 591-594.

Hvidberg, C.S.  2000.  When Greenland ice melts.  Nature 404: 551-552.

What was done
Previous model estimates of the Greenland ice sheet's contribution to sea level rise during the last interglacial were one to two meters.  Cuffey and Marshall reevaluated these estimates based on a recalibration of oxygen-isotope-derived temperatures from central Greenland ice cores.

What was learned
The results of Cuffey and Marshall's model analysis suggest that the Greenland ice sheet was much smaller during the last interglacial than previously thought.  Melting of the ice sheet, they estimate, contributed somewhere between four and five and a half meters to sea level rise.

What it means
One of the major concerns of believers in CO2-induced global warming is that rising global temperatures may result in the rapid melting and collapse of the West Antarctic Ice Sheet.  However, according to Hvidberg, Cuffey and Marshall's results imply that "high sea levels during the last interglacial should not be interpreted as evidence for extensive melting of the West Antarctic Ice Sheet, and so challenges the hypothesis that the West Antarctic is particularly sensitive to climate change."  Nevertheless, the possibility exists that sea levels in the present interglacial may rise to the height of those of the last interglacial as a result of a major shrinking of the Greenland ice sheet.  Such a scenario does not bode well for coastal populations, but Cuffey and Marshall estimate that the widespread melting of the Greenland ice sheet took place over the course of a few millennia, which, according to Hvidberg, draws a "less dramatic picture than the suggested collapse of the West Antarctic Ice Sheet, with its accompanying rapid increase in sea level."

Reviewed 1 June 2000