Model predicts more snow at the poles

Posted by Kate Taylor

Most of us will see less snow over the coming years - but polar and high-altitude regions will get more, a new climate model from the National Oceanic and Atmospheric Administration (NOAA) predicts.

As carbon dioxide levels rise, there will be an increase in snowfall for the Arctic and Antarctic, along with the highest altitudes, but an overall drop in snowfall for the globe.

The decline in snowfall, say the researchers, could spell trouble for regions such as the western United States that rely on snowmelt as a source of fresh water.

The model indicates that the majority of the planet would experience less snowfall if atmospheric carbon dioxide doubles; observations show it's already up 40 percent from the mid-19th century, and is likely to double this century.

In North America, the greatest reductions in snowfall will be seen along the northeast coast, in the mountainous west, and in the Pacific Northwest, says the team. Indeed, coastal regions from Virginia to Maine, as well as coastal Oregon and Washington, will get less than half the amount of snow they do now.

In very cold regions of the globe, however, snowfall will rise, because as air warms it can hold more moisture, leading to increased precipitation in the form of snow.

The model explains why high-altitude regions haven't experienced the decline in snowfall predicted by some other models. It shows the highest mountain peaks in the northwestern Himalayas, the Andes and the Yukon region receiving more snow when carbon dioxide doubles.

And it's a big improvement over previous models, say its developers, in that it incorporates more detail about mountains, valleys and other topographical features - "analogous to having a high-definition model of the planet's climate instead of a blurred picture," they say.