|Friday, October 17, 2008
21:15 - I'm so confused
Sheesh. Who do we believe?
The National Snow and Ice Data Center, via Google Earth Blog?
The ice in the Arctic officially reached the summer minimum on September 12th after a blazing summer in the North. The ice reached the second highest minimum in recorded history just a bit less than 2007 where almost half the ice disappeared off the cap of the world. Read the official post from the National Snow and Ice Data Center (NSIDC). The NSIDC has produced a number of excellent animations for Google Earth depicting real-time analysis of the amount of ice on both poles over time. Using a demarcation line of the average ice melt extents over the past few decades as a reference, you can compare the current levels and see just how bad the melting has been the last two years.
Or the USGS via Anchorage Daily News and DailyTech?
Alaskan Glaciers Grow for First Time in 250 years
A bitterly cold Alaskan summer has had surprising results. For the first time in the area's recorded history, area glaciers have begun to expand, rather than shrink. Summer temperatures, which were some 3 degrees below average, allowed record levels of winter snow to remain much longer, leading to the increase in glacial mass.
"In mid-June, I was surprised to see snow still at sea level in Prince William Sound", said glaciologist Bruce Molnia. "In general, the weather this summer was the worst I have seen in at least 20 years".
"On the Juneau Icefield, there was still 20 feet of new snow on the surface [in] late July. At Bering Glacier, a landslide I am studying [did] not become snow free until early August."
Molnia, who works for the US Geological Survey, said it's been a "long time" since area glaciers have seen a positive mass balance -- an increase in the total amount of ice they contain.
Since 1946, the USGS has maintained a research project measuring the state of Alaskan glaciers. This year saw records broken for most snow buildup. It was also the first time since any records began being that the glaciers did not shrink during the summer months.
Those records date from the mid 1700s, when the region was first visited by Russian explorers. Molnia estimates that Alaskan glaciers have lost about 15% of their total area since that time -- an area the size of Connecticut.
One of the largest areas of shrinkage has been at the national park of Glacier Bay. When Alexei Ilich Chirikof first arrived in 1741, the bay didn't exist at all -- only a solid wall of ice. From that time until the early 1900s, the ice retreated some 50 miles, to form the bay and surrounding area.
So who does have a clue about what the climate is doing, anyway?
The basic facts seem to be consistent across the two sources—melting was less this year than in 2007. But is that an indication that things were almost as bad as the worst thing ever—or that this is, impressively, the first recorded reversal of a two-and-a-half-century monotonic trend?
All I know is that if Glacier Bay lost most of its ice in the 150 years prior to 1900, it wasn't because of people driving Hummers.