Wednesday, March 26, 2008

Antarctic Ice Shelf Collapsing

"Scientists monitoring satellite images of the Wilkins Ice Shelf spotted that a huge (41 by 2.5 km) berg the size of the Isle of Man appears to have broken away in recent days – it is still on the move... A large part of the Wilkins Ice Shelf on the Antarctic Peninsula is now supported only by a thin strip of ice hanging between two islands."

Cnet has some pictures.

Salon reports in Bye-bye, Antarctica? - How the World Works about how the deniers are describing this. It turns out it is a little confusing. It seems the mainland of Antartica has been cooling for the last 30 years. So the deniers ask how could the collapse be about global warming. Of course the collapse was on the pennisula which (I think) hasn't been cooling.

Global Warming models have predicted a cold Antarctica and southern ocean for a while. That sound contradictory but apparently it's not. It has to do with how heat is stored in oceans. "As greenhouse gases increase, the heat seeps gradually deeper and deeper into the oceans. But when larger volumes of water are brought into play, they bring a larger heat capacity. Thus as the years passed, the atmospheric warming would increasingly lag behind what would happen if there were no oceans." So the warming happens first deep in the oceans and won't show up in the atmosphere until later. Also since the southern hemisphere has more ocean than the north, it will heat slower.

"Computer models have improved by orders of magnitude, but they continue to show that Antarctica cannot be expected to warm up very significantly until long after the rest of the world’s climate is radically changed."

Still though, as I read that I still have to wonder why an iceberg 5 times the size of Manhattan has already collapsed in Antarctica. I'm not by any means a denier but I clearly don't understand what's expected to happen. And with all the world's reputable scientists agreeing on this, you'd think at least one of them would be able to explain it to the public.

Also I hadn't realized this from the Salon article. "It's amazing, really. Pick a random datapoint of climate skepticism floating through the infosphere, and you can almost invariably connect the dots back to Exxon."

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