Thursday, January 04, 2007

Droughts are not worse, and Glaciers are retreating less

A new study by Pederson et al. (2007) does analsis on tree ring data and soil moisture variability from the highly talked about Glacier National Park. As shown below they evaluated the length of droughts in the area.

This obviously shows a large dought between 1917 to 1941 but quote that

“In terms of intensity (magnitude/duration), the 1917–41 drought was surpassed only by the drought of 1601–09.”

Just from the look of the graph, one cannot find any increase or decrease in drought activity in the area, and there is nothing to suggest that global warming in the past 30 years has influenced the area.

However, the most talked about thing in the park is it's namesake, largely, the Sperry Glacier. As shown below they say that the glacier measured 3.76km squared in 1850, 3.31km squared in 1913, 1.43km squarewd in 1945, 0.97km squared in 1979 and 0.87 km squared in 2003.

So therefore the amount of retreat of the glacier during the global warming stage from the 1970s to now has been 0.10km squared, which is obviously a lot less than it was in the past. The retreat of the glacier was at most between 1913 and 1945, where the drought of the area occured.

Whilst it looks as though the glacier will continue to retreat, there are no signs at all that it will retreat faster than it has in the past. Seems like global warming has very limited effect on the Sperry Glacier.

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