I got a lot of comments on the story of the calving of the Ayles Ice Shelf, including a very informative one from Mauri Pelto, a glaciologist at Nichols College. I sent an e-mail to Dr. Luke Copland, an assistant professor of geography at the University of Ottawa. Dr. Copland was quoted in the article I linked and he was kind enough to respond. Here's the text of the e-mail:
I'm going to extrapolate a bit from this but as I read Dr. Copland's statement, it seems that he is saying that the Arctic ice has been melting for at least a century. The ice shelves were only discovered a century ago so this might have been going on longer. That says that this is not a phenomenon caused by recent warming. If this is the largest loss in 25 years then larger sheets have broken off earlier, presumably before recent warming.
Thanks for the good question - there have been many breakups of ice shelves across northern Ellesmere Island over the last century so. When these ice shelves were first discovered in about 1900, they were a total of about 10,000 sq km in area. Today they have reduced in size by about 90%, to about 1000 sq km in area. The Ayles Ice Shelf loss was the largest breakup in at least 25 years, but it is part of the long-term trend of loss over the last century.
The important point to note with all of these losses is that they are essentially permanent. There is no longer enough glacier ice flowing off the land to replace the ice that is being calved into the ocean. Hence these 3000+ year old shelves are now gone forever.
You might also be interested in looking at a media page that we've put together:
I'll even speculate that if the sheets of ice are over 3,000 years old then the conditions that caused them must have changed without human intervention and they might even have been melting for a very long time prior to human-induced CO2.
Even without my specuation, it seems that this is not something new or a sign that the world is suddenly warmer than ever before.
Then there are the polar bears. They are threatened by Global Warming. Al Gore said so and the government is investigating classifying them as endangered.
The funnt thing is that, according to the Wall Street Journal, polar bears are at a historic high. How can they be threatened? The whole thing is part of a settlement. Some Green groups sued the government to force them to classify the polar bears as threatened by GLobal Warming. Granted that warming such as some project would change the bears' environment, possibly threatening them but they are not threatened yet and Al Gore's predictions are still questionable.
The current action is akin to filing for an insurance settlement because a forecaster said that this will be a bad year for storms and your beachfront property is at risk.