The Arctic ice cap has stopped growing and started melting.
March was a good month for ice in the Arctic. Arctic sea ice peaked on March 18 and March added a total of 54,000 square miles during the month. 2012 had the 9th lowest March in the 34 year record. February of 2012 was the 5th lowest February in the record…so March really did well ….if you like Arctic Ice. Interestingly, March is normally (if anything can be called normal with only a 34 year history) a melting month.
The following graph was prepared by the National Snow and Ice Data Center, which can be accessed through the following link
Conventional wisdom of 1975 stated that the Arctic Ice Sheet was growing rapidly. Data that begins in 1979 does not show 30 years of ice growth from the 1940’s to the 1970’s and that must be taken into consideration when evaluating this rather small data set.
The Arctic was cold in March this year, and the Eastern USA wasn’t. Interesting, but not surprising….we all must resist the temptation to draw worldwide conclusions from regional data.
Yes there is more ice, but the ice is thinner than in past years and much of it is first year ice…so we could see it all melt rather quickly.
Fresh water freezes before salt water. As sea ice freezes, the initial ice has less salt than the ocean. A salt rich liquid is formed in lenses throughout the ice. As the ice continues to freeze, the liquid remaining becomes saltier and saltier. When Spring comes, the salty lenses are released into the ocean and replaced with the much less salty sea water. If the remaining ice lasts through the summer it becomes second year sea ice. Second year ice has less salt content, is stronger and it melts more slowly.
When the Arctic has a very warm summer as it did in 2007, it takes at least 2 cold years to recover that ice because of the way sea ice is created.
World climate is very complicated, and just about everybody simplifies it too much. I don’t know what will happen next…but as a person that lives in a northern climate…I really don’t want the ice cap to get bigger. So a rapidly expanding ice cap isn’t necessarily a source for celebration for me.
World leaders met in Copenhagen in December of 2009. The UN wanted to extend the Kyoto treaty that is set to expire at the end of 2012. When those meetings failed to produce an agreement, Al Gore predicted the Arctic Ice Cap would be gone in the summer in 5 years and global carbon dioxide levels would accelerate. So far at least, he has been wrong.
I like seeing Al Gore proven wrong…but I don’t really want a colder world…so I am of two minds. I am confident Al Gore is a big time wild ass guesser, and I would like the world to stay nice and toasty…as long as it doesn’t warm too much.
A growing ice cap may be good for polar bears, or maybe not…but I know it’s not good for me.