Monday, June 30, 2014

Polar Ice: Negative Feedback

One of the interesting facts about Polar ice is that the decline in Arctic sea ice has been matched by an increase in Antarctic sea ice. This year's Antarctic ice is currently at dramatically record levels, and recent years have all had a lot of ice. Arctic and Antarctic ice have different dynamics, so one should not make the denialist assumption that this is some sort of evidence against global warming, but, just as less ice in the Arctic causes a net decrease in planetary albedo, increasing Antarctic ice has the opposite effect. The Antarctic sea ice area anomaly is currently more than + 2 million km^2, or roughly twice the - 1 million km^2 Arctic sea ice area anomaly.

I wonder what the average net forcing over a year looks like. Anybody have these numbers handy?