As a result of global warming, Tibet’s mighty glaciers are retreating at a startling rate. The U.N.’s panel on climate change warned that they could vanish completely within three decades.

Below is an article written by Tim Johnson and published by Phayul.com:

KAROLA PASS, Tibet — The glaciers of the Himalayas store more ice than anywhere on Earth except for the polar regions and Alaska, and the steady flow of water from their melting icepacks fills seven of the mightiest rivers of Asia.

Now, because of global warming and related changes in the monsoons and trade winds, the glaciers are retreating at a startling rate, and scientists say the ancient icepacks could nearly disappear within one or two generations.

Curiously, there’s little sense of crisis in some of the mountainous areas. Indeed, global warming is making the lives of some high-altitude dwellers a little less severe.

Effects

Here at the foot of the towering Nojin Gangsang mountain, an ice-covered 23,700-foot peak, herders notice the retreat of the glaciers but say they feel grateful for the milder winters and increasing vegetation on mountain slopes in summers.

But for people living in the watershed of the Himalayas and other nearby mountain ranges along the Tibetan Plateau, glacial melt could have catastrophic consequences.

Himalayan glaciers release water steadily throughout the year, most critically during the hot, dry, sunny periods when water is most needed. Once they vanish, major lifeline rivers such as the Ganges and Indus could become more seasonal, and large tributaries may dry up completely during nonmonsoon periods.

The pace of glacial retreat around the Himalayas varies. Smaller glaciers fragment and melt faster than bigger ones, and those facing south also are receding more quickly.

U.N. estimate

In a stark forecast, the United Nations body studying global warming, the Intergovernmental Panel on Climate Change, warned in early May that the glaciers in the world’s highest mountain range could vanish within three decades.

“Glaciers in the Himalayas are receding faster than in any other part of the world and, if the present rate continues, the likelihood of them disappearing by the year 2035 and perhaps sooner is very high if the Earth keeps getting warmer at the current rate,” the report said. The total area of glaciers in the Himalayas likely will shrink from 193,051 square miles to 38,600 square miles by that year, the report said.

While some scientists dispute the assessments of the U.N. body and the rate of retreat is highly variable, experts on glaciers in China, India and Nepal already see the short-term effect of glacial melting.

As the glaciers recede, lakes on the Tibetan Plateau are rising, and experts foresee floods, landslides and mudflows from mountain lakes overrunning their banks.

“They can cause tremendous loss of property, or even lives. They can destroy bridges, villages and roads,” said Yao Tandong, one of China’s premier glacier scientists and director of the Institute of Tibetan Plateau Research, in China’s capital, Beijing.

People affected

Glacial runoff in the Himalayas is the largest source of freshwater for northern India, and provides more than half of the water to its most important river, the Ganges.

Glacial runoff also is the source of the headwaters for the Indus River in Pakistan, the Brahmaputra that flows through Bangladesh, the Mekong that descends through Southeast Asia, the Irrawaddy in Burma, and the Yellow and Yangtze rivers of China.

Scientists say 1.3 billion people reside in areas affected by glacial retreat, either in flood-prone areas or in locales that rely on year-round supplies of fresh water from glaciers rather than from the monsoon rainfall of only three or four months.

The retreating glaciers are occurring across an area that’s the largest high-altitude land mass on the planet, bordered by the Himalayas to the south, the Tian Shan range to the north, and the Pamirs and the Karakorum mountains to the west.

Throughout the area, experts say, dwindling glaciers may lead to unstable mountainsides, greater sedimentation in rivers and disrupted irrigation systems, in addition to threatening water supplies to large populations.