Global warming? Antarctic ice growing thicker
Here's some fodder for the crowd that scoffs at global warming: Antarctic ice has grown more solid over the last 20 years.
So says a video report by BBC science editor David Shukman, who notes that in Antarctica, "The bulk of the ice sheet is largely unchanged, or even getting slightly thicker."
But before the jeering gets too loud: The overall condition of all polar ice, is, you guessed it, melting. That takes into account considerable thawing in the Arctic, as well as in coastal areas of western Antarctica that buck the continent's hardening trend.
Shukman's report notes that scientists now definitely know the extent to which the polar ice melt has contributed to sea level rises - 11 millimeters (0.43 inches) over the last 20 years. And they can also say for certain that the melting is accelerating.
Why are they all of a sudden so sure? Because the latest numbers pool the findings of 10 satellites from different countries. They also draw on 20 different polar research teams who collaboratively reported in Science.
"People have been a little bit confused in the past because there have been different messages over different time periods," says lead author Professor Andrew Shepherd of Leeds University in the video report, which includes spectacular footage of Greenland glaciers crashing to the ocean (the BBC won't let me embed, but click on the link above to view).
"What we find is sometimes the ice sheets grow, and sometimes they shrink," he says. "You need to measure them over 20 years to be able to see the true story. And the true story is that the ice losses have increased."
Dr. Hamish Pritchard of the British Antarctic Survey adds, "The next big challenge is to predict what will happen over, say, the next century. And that is going to be a tough challenge. There are lots of difficult processes to understand going on in there."
The 0.43-inch rise might not sound like a lot. But as Shukman notes, "It could be very serious if the trend continues."
Anyone who lost their home to Hurricane Sandy last month or to the recent floods in a country that I now call Lake England should know what he means.
Photo: Vincent van Zeijst via Wikimedia.
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— By Mark Halper on November 28, 2012, 4:00 PM