A new, full-century model offering a detailed picture of climate change predicts that most mountains in the world will suffer a drastic decline in snowpack by the end of this century, scientists reported on Thursday.

The Andes in South America will have less than half their current winter snowpack, mountain ranges in Europe and the U.S. West will have lost nearly half of their snow-bound water, and snow on New Zealand's peaks will all but have vanished, said the scientists at the Pacific Northwest National Laboratory of U.S. Department of Energy.

The decline in winter snowpack means less spring and summer runoff from snowmelt. That translates into unprecedented pressure on people worldwide who depend on summertime melting of the winter snowpack for irrigation and drinking water.

Hardest hit are mountains in temperate zones where temperatures remain freezing only at increasingly higher elevations, said Steven Ghan, lead author of the study published in the latest issue of the Journal of Climate.

Alaska in 2100 will maintain but 64 percent of its year 2000 snowpack. In Europe, the Alps will be at 61 percent and Scandinavia 56 percent. The Andes will drop to 45 percent.

Mt. Cook and its snowcapped neighbors in New Zealand will be much less scenic with just 16 percent of their current coverage, the model predicted.

The model, which actually simulated years 1977 to 2100 using known data for calibration, generates snow information using some of the most advanced computer prediction methods to date.

The researchers chopped the world's mountain ranges into 10 different "elevation classes." For each elevation class, data such as air circulation, moisture and temperature was used to determine snowfall to the surface.

The surface snow was distributed across the grids according to the local surface elevation. Then the entire simulation ran on a supercomputer over a few weeks.

However, there are significant limitations to the model, cautioned the researchers.

For example, field observations in Africa suggest the famous snows of Mt. Kilimanjaro will be gone within decades, and on Greenland signs point to accelerated snow and ice melt, but the climate model fails to show that.

The model does not account for all of the possible snow loss, it neglects downward flow of snow by avalanches and snow slides, glacial creep in places where snowfall is heavy and the snow does not have time to melt, according to Ghan.

Source: Xinhua