Conway, H., Hall, B.L., Denton, G.H., Gades, A.M. and Waddington, E.D. 1999. Past and future grounding-line retreat of the West Antarctic Ice Sheet. Science 286: 280-283.
What was done
The authors examined previously reported research, as well as conducted their own research, in regard to the glacial retreat of the West Antarctic Ice Sheet (WAIS) since its maximum glacial extent some 20,000 years ago.
What was learned
The grounding line of the WAIS remained near its maximum extent until about 10,000 years before present, whereupon it began to retreat at a rate of about 120 meters per year. Currently, it is retreating at about the same rate, and, if it continues to do so, complete deglaciation of the WAIS will occur in about 7000 years.
What it means
According to the authors, the modern-day grounding-line retreat of the WAIS is part of an ongoing recession that has been underway since the early to mid-Holocene. As a result, according to the authors, "it is not a consequence of anthropogenic warming or recent sea level rise." Hence, it is clear that climate change advocates who argue that CO2-induced global warming is responsible for every iceberg that breaks free of the WAIS, or every inch of WAIS retreat, are unjustified in continuing to make such claims.
Reviewed 15 October 1999