Thursday, August 28, 2008

North Polar Ice Cap: Another Record Low in Store?

One more weather post while we're on the topic. Last year, the north polar ice cap made news when it shrunk to the smallest it's been since modern measurements have been taken.




It looks like this summer will be a repeat, or at least close. Here's the data:



By this point last summer there was slightly less sea ice in the northern hemisphere than this year, then it leveled out. If September is unusually warm (or sunny), this year could still break the record. In any event, the older, thicker sea ice is rapidly disappearing, being replaced by thinner new ice.

The melting sea ice has negligible impact on ocean sea levels, but could be a harbinger of things to come if melting of the Greenland ice sheet also accelerates.

By the way, last summer the Global Warming Deniers could at least point to Antarctica to offset alarm over the melting north pole, as the extent of southern hemisphere sea ice reached a record high (it's winter down there, so the ice is going in the opposite direction). But that's not the case this summer. Instead, southern sea ice is significantly below last year's pace, and for the first time in the past 12 months is below the average (technically, mean) level of the past 20 years.

We're sure the GWD's, aided by a few Exxon dollars, will come up with something, however.

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