About that Antarctic ice shelf
April 1, 2008
I heard only a snippet of a report about this while away on vacation, because Grace’s grandparents only listen to the CBC (and nothing else), and the news was playing over breakfast most mornings. Predictably, Mothercorp had some dial-an-expert come on the program to claim that the “breaking off” of a huge iceberg from the Wilkins Ice Shelf in Antarctica was a sure-fire sign of the spreading influence of global warming-influenced climate change.
To his credit, the CBC reporter did mention (briefly) that parts of Antarctica seem to be cooling, while others seem to be warming — but any objectivity that statement might have given to the news piece as a whole evaporated (heh) when the dial-an-expert (sorry, I didn’t catch his name while I was passing the bacon) spoke up.
Predictably, though, this iceberg breaking off is not the harbinger of doom it was made out to be.
The full Wilkins 6,000 square mile ice shelf is just 0.39% of the current ice sheet (just 0.1% of the extent last September). Only a small portion of it between 1/10th-1/20th of Wilkins has separated so far, like an icicle falling off a snow and ice covered house. And this winter is coming on quickly. In fact the ice is returning so fast, it is running an amazing 60% ahead (4.0 vs 2.5 million square km extent) of last year when it set a new record. The ice extent is already approaching the second highest level for extent since the measurements began by satellite in 1979 and just a few days into the Southern Hemisphere winter and 6 months ahead of the peak. Wilkins like all the others that temporarily broke up will refreeze soon. We are very likely going to exceed last year’s record. Yet the world is left with the false impression Antarctica’s ice sheet is also starting to disappear.
Ice shelves breaking off to form icebergs is a pretty common phenomenon, or so I’ve heard. It isn’t the climate that has changed in an extreme and dangerous way — what has changed thusly is our ability to look at the normal dynamics of our environment in a rational and calm manner.
