In a study published in “Environmental Research Letters,” researchers said that rising temperatures melted an area the size of France last season – the largest melt-region since records began in 1979.
“This past melt season was exceptional, with melting in some areas stretching up to 50 days longer than average,” said study co-author Marco Tedesco, director of the Cryospheric Processes Laboratory at The City College of New York.
“Melting in 2010 started exceptionally early at the end of April and ended quite late in mid- September,” he added.
Analyzing satellite and land surface data, researchers found that the area vulnerable to melting has been steadily increasing by about 17,000 kilometers a year. That is “equivalent to adding melt-region the size of Washington state every ten years,” Tedesco said on his research website.
After the warmest spring and summer on record, reduced snowfall left ice exposed longer than normal.
“Bare ice is much darker than snow and absorbs more solar radiation,” said Tedesco. “Other ice melting feedback loops that we are examining include the impact of lakes on the glacial surface, of dust and soot deposited over the ice sheet and how surface meltwater affects the flow of the ice toward the ocean.”
The findings are significant because Greenland’s ice sheet, which makes up about one-twentieth of the world’s ice, is quickly becoming a major contributor to rising sea levels. Although it currently only adds about .02 inches to global levels each year, that amount could dramatically increase. Were it to melt completely, it would raise sea levels by about 21 feet.