Climate change

LOS ANGELES -- The dramatic shrinking of Arctic Sea ice and the Northern Hemisphere's glaciers and snowfields has reduced the radiation of sunlight back into space more than scientists previously predicted, according to a new study in the journal Nature Geoscience.

As a result, the ocean and land mass exposed by the melting ice and snow have absorbed more heat, contributing to global warming.

The "albedo" effect, in which the white cover reflects radiation from sunshine, has been calculated in numerous computer-generated climate models. But the new study goes beyond those theoretical calculations. Using field measurements and satellite observations, a team led by University of Michigan researcher Mark Flanner found that the warming effect of the loss of snow and ice is "substantially larger" than was predicted in the estimates of 18 climate models.

CANCUN, Mexico -- The lives and livelihoods of people in South Asia are at "high risk" as global warming melts glaciers in the Himalayas, sending floods crashing down from overloaded mountain lakes and depriving farmers of steady water sources, U.N. and other international experts reported Friday.

Worldwide, "since the beginning of the 1980s, the rate of ice loss has increased substantially in many regions, concurrent with an increase in global mean air temperatures," the U.N. Environment Program said.

Glaciers in southern South America and Alaska's coastal mountains have been losing mass faster and for longer than glaciers elsewhere in the world, it said.