Saturday, March 14, 2015

Talking to Republicans about 'that which should not be named,' at least in Florida

A Reagan approach to climate change

By George P. Shultz March 13, WashPost

George P. Shultz was secretary of state from 1982 to 1989.

The trend of disappearing summer sea ice in the Arctic is clear even though there is always some variability from year to year. Severe winter weather underscores the importance of keeping track of significant trends. Here are the numbers, according to Julienne Stroeve, of the National Snow and Ice Data Center in Boulder, Colo., as reported in the Economist in February:

“Between 1953 and 2014, the average area of the Arctic sea ice shrank by 48,000 square kilometers a year.”

“Between 1979 and 2014, it shrank by 87,000 square kilometers a year.”

“Between 1996 and 2014, the rate rose to 148,000 square kilometers.”

The accelerating rate is explained in part by the fact that ice reflects sunlight but water, which is darker, absorbs it. So as water replaces ice, more heat is retained. Heat transported from lower latitudes could also be part of the explanation.

The picture in Greenland is more complicated, but it is important in the long run. Arctic ice is already in the water, so melting there won’t make much of an impact on sea levels. Greenland, though, is home to the world’s second-largest land ice mass. Two satellites measure annual melting in Greenland; over the past two decades its net ice loss has been about 140 billion tons per year, and that rate has almost doubled in more recent years. The story is similar in West Antarctica, where surface geography makes it easier for large segments of its ice sheet to slide into a warming ocean. Altogether, we can observe that sea levels are now rising about 3 millimeters per year. We can also observe that the last time the earth warmed by a few degrees — 120,000 years ago — sea levels were at least 5 meters higher than today.

(More here.)

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