There is a nice article in the
latest EOS, a publication of the American Geophysical Union, discussing the remarkable ice cover on the upper Great Lakes this past spring [See Cold Water and High Ice Cover on the Great Lakes in Spring 2014 by Clites et al. (2014), unfortunately paywalled unless you are an AGU member and login with your membership account].
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| Source: Clites et al. (2014) |
Some tidbits from the paper:
- Lake Superior wasn't completely ice free until June 6th. Yeah, June!
- At the end of April, 51% of Lake Superior, 23% of Lake Huron, and 10% of Lake Michigan were still ice covered.
- In the 40-year period of record at the end of April, the previous record on Lake Superior was 30%, in only a few years was significant ice observed on Lake Huron, and at no time was their significant ice on Lake Michigan.
A quick look at data from NCDC shows that this past Dec–Apr was the coldest in Michigan (which flanks Lakes Superior, Michigan and Huron) since 1920 and the 4th coldest on record. The period is a dramatic outlier during the 40-year period of good ice-cover records.
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| Source: NCDC |
During the same period, globally averaged temperatures were the 6th warmest on record, illustrating that Mother Nature can still bring it, but only regionally.
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| Source: NCDC |
Your global graph sure looks like:
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2) Flat temperatures 1940-1970
3) Rising temperatures 1970-2000
4) Flat temperatures since 2000
That's a rather simple-looking pattern not yet explained satisfactorily by the climate models.
How about a 30 year cyclical pattern overlaid by greenhouse gas increases NOT multiplied by speculative positive feedback assumptions?
Having had a lot of nice swims in Huron for the last two summers, I can definitely say that I don't appreciate late ice coverage as much as others might. ;)
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