Bad weather was good for Alaska glaciers: Alaska News | adn.com

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 chill 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.

"In general, the weather this summer was the worst I have seen in at least 20 years."

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.
...
One cool summer that leaves 20 feet of new snow still sitting atop glaciers come the start of the next winter is no big deal, Molnia said.

Ten summers like that?

Well, that might mark the start of something like the Little Ice Age.
...
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.

Rivers of ice flow slowly. Hundreds of feet of snow would have to accumulate at higher elevations to create enough pressure to stall the current glacial retreat and start a new advance. Even if the glaciers started growing today, Molnia said, it might take up to 100 years for them to start steadily rolling back down into the valleys they've abandoned.

"It's different time scales," he said. "We're just starting to understand."

As strange it might seem, Alaska's glaciers could appear to be shrinking for some time while secretly growing. Molnia said there are a few glaciers in the state now where constant snow accumulations at higher elevations are causing them to thicken even as their lower reaches follow the pattern of retreat fueled by the global warming of recent decades.