The future of hundreds of millions of people across the world will be affected by declines in snow cover, sea ice, glaciers, permafrost and lake ice, a United Nation's report published yesterday said.

There are likely to be significant changes to the availability of water supplies for drinking and agriculture, while rising sea levels will impact on low lying coastal regions and islands, it said.

The UN Environment Program (UNEP) said in its "Global Outlook for Ice and Snow" that an estimated 40 percent of the world's population could be affected by loss of snow and glaciers on the mountains of Asia.

The report was launched yesterday to mark World Environment Day that falls today.

Melting ice and snow are also likely to increase flooding due to a buildup of potentially unstable glacial lakes, the report said.

Rising temperatures and the thawing of frozen land, the permafrost, is triggering the expansion of existing - and the emergence of new - water bodies in places like Siberia, it said.

Also, the increase of methane levels in the atmosphere, is making holes in the lakes' icy surfaces even during the sub-zero winter months. While less snow and sea ice are leading to more of the sun's heat being absorbed by the land and the polar oceans, which in turn may speed up global climate change, the report said.

Achim Steiner, the UN undersecretary-general and UNEP executive director, said: "This report might to some people seem to address issues from remote and far away places. But it underlines the fate of the world's snowy and icy places in a climatically challenged world should be cause for concern across the world."

The report also warned that the volume of frozen land in China is expected to decline by 30 to 50 percent this century due to climate change.

Frozen ground or permafrost is important for the stability of buildings and infrastructure, the report said.

The report said China was one of a number of countries that are already adapting infrastructure to cope with projected permafrost thawing.

The Qinghai-Tibet Railway, for instance, factors in the likely impact of a 2.6 C temperature rise by incorporating cooling techniques.

"The impact of climate changes on stability will also need to be considered in the design of the proposed China-Russia oil pipeline," the report said.

(China Daily 06/05/2007 page4)