Forty Signs of Rain

The icecap of Greenland is melting at an accelerating pace, says a group of researchers at the University of Texas, and there are indications that the West Antarctica Ice Sheet is also melting.

A recent report from the Intergovernmental Panel on Climate Change -- known as the IPCC -- estimated that during all of the past century worldwide melting ice from global warming had raised sea levels by only two-tenths of a millimeter a year, or about 20 inches for the entire century.[sic]

But, according to Chen and his Texas team, the melting of Greenland's ice cap is already raising global sea levels by six-tenths of a millimeter each year, and the Colorado group estimates that melting of the West Antarctic Ice Sheet alone is adding up to four-tenths of a millimeter of fresh water to sea levels each year. In other words, the global sea level, due to melting of the ice in Greenland and Antarctica combined, is already rising 10 [sic] times faster than the IPPC's tentative estimates, the two analyses indicate.

(The arithmetic in the SF Gate article reporting the news is serisously deficient. Over the course of 100 years, a rise of 0.2 mm/year amounts to 20 mm [about 0.8 inches], not 20 inches. And 0.6 mm/year + 0.4 mm/year = 1.0 mm/year, which is five times, not ten, the historical 0.2 mm/year reported by the IPCC.)

Notwithstanding the reporter's bad math, it is dire news indeed that the icecaps are melting at such speeds. The Chronicle article raises the spectre of fresh-water melt from Greenland shutting off the Gulf Stream, just like in a Stan Robinson novel.