The Ice Have It

Maximum and minimum ice cover surrounding Antarctica, 2008-2009

Minimum and maximum ice cover over the Arctic Ocean, 2008-2009

The extraordinary complexity of predicting with great confidence and precision the exact effects of climate warming are emphasized in two new studies of the earth’s polar regions. New Insight into Decline of Arctic Sea Ice Cover explains in just what way we have previously underestimated the propensity of the Arctic Ocean ice to deform, fracture, disperse and melt, leading to a significant underestimate of the pace of and degree to which the icecap over the north pole has melted. Contemporaneously, it appears we have made the opposite error in assuming the effect of melting in the south polar regions — overestimating sea level rise consequent to even total melting of the West Antarctic ice sheet.

Want to learn more? NASA’s Earth Observatory has an excellent overview article on Sea Ice, complete with a number of interesting charts and photos.