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Greater impact of snow, ice melt measured

  |   Jan. 19, 2011 at 8:17 PM
CORVALLIS, Ore., Jan. 19 (UPI) -- Arctic "albedo feedback," reflection of sunlight back to space from snow and ice, has decreased more than twice what climate models show, U.S. researchers say.

Scientists say the findings are significant because they suggest the loss of reflectivity could amplify arctic warming much more than previously thought, ScienceDaily.com reported Wednesday.

"The cryosphere isn't cooling the Earth as much as it did 30 years ago, and climate model simulations do not reproduce this recent effect," Karen Shell, an Oregon State University atmospheric scientist, said.

The cryosphere is the collective portion of Earth's surface where water is in solid form as sea ice, snow, lake and river ice, glaciers, ice sheets and frozen ground.

Most of these frozen areas are highly reflective, and bounce sunlight back into the atmosphere, keeping Earth cooler than it would be without the cryosphere.

But as temperatures increase, areas of ice and snow melt and reflectivity decreases, Shell said.

"Instead of being reflected back into the atmosphere, the energy of the sun is absorbed by the Earth, which amplifies the warming," Shell said. "Scientists have known for some time that there is this amplification effect, but almost all of the climate models we examined underestimated the impact -- and they contained a pretty broad range of scenarios."

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