I Blame Global Warming III

The nearly coldest summer on record in Alaska has already made it increasingly difficult to lay awake nights worrying about global warming. Now there is this:

Bad weather was good for Alaska Glaciers

Two hundred years of glacial shrinkage in Alaska, and then came the winter and summer of 2007-2008.

Unusually large amounts of winter snow were followed by unusually chilly temperatures in June, July and August.

"In mid-June, I was surprised to see snow still at sea level in Prince William Sound," said U.S. Geological Survey glaciologist Bruce Molnia. "On the Juneau Icefield, there was still 20 feet of new snow on the surface of the Taku Glacier in late July. At Bering Glacier, a landslide I am studying, located at about 1,500 feet elevation, did not become snow free until early August.

Never before in the history of a research project dating back to 1946 had the Juneau Icefield witnessed the kind of snow buildup that came this year. It was similar on a lot of other glaciers too.

As it happens, glaciers have been receding in Alaska since the most recent maximum in the 1700s. Since then, Alaskan glaciers have lost about 15% of their area. Why might that be?

Climate change has led to speculation they might all disappear. Molnia isn't sure what to expect. As far as glaciers go, he said, Alaska's glaciers are volatile. They live life on the edge.

"What we're talking about to (change) most of Alaska's glaciers is a small temperature change; just a small fraction-of-a-degree change makes a big difference. It's the mean annual temperature that's the big thing.

Yes, I know when it comes to glaciers I am part of the great ignoranti in comparison with Mr. Molnia. I shall risk disagreement, nonetheless.

This "fraction-of-a-degree" stuff is AGW as religion. Over the long term, whether glaciers expand or contract is solely dependent upon the difference between winter snow accumulation and summer melt. It is clearly possible that an increase snowfall will more than offset warmer temperatures, just as cooler temperatures will not mean expanding glaciers if the local winter climate features less snow.

Fortunately, though, the balance of the article is less theological:

During the Little Ice Age -- roughly the 16th century to the 19th -- Muir Glacier filled Glacier Bay and the people of Europe struggled to survive because of difficult conditions for agriculture. Some of them fled for America in the first wave of white immigration.

The Pilgrims established the Plymouth Colony in December 1620. By spring, a bitterly cold winter had played a key role in helping kill half of them. Hindered by a chilly climate, the white colonization of North America through the 1600s and 1700s was slow.

As the climate warmed from 1800 to 1900, the United States tripled in size. The windy and cold city of Chicago grew from an outpost of fewer than 4,000 in 1800 to a thriving city of more than 1.5 million at the end of that century.

The difference in temperature between the Little Ice Age and these heady days of American expansion?

About three or four degrees, Molnia said.

The difference in temperature between this summer in Anchorage -- the third coldest on record -- and the norm?

About three degrees, according to the National Weather Service.

Does it mean anything?

Nobody knows. Climate is constantly shifting. And even if the past year was a signal of a changing future, Molnia said, it would still take decades to make itself noticeable in Alaska's glaciers.

I'm surprised this snuck by the Anchorage Daily News editorial staff and their masters at McClatchy Newspapers.

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To learn more than just about anyone needs to know about Alaskan glaciers, read this.