Water crisis looms as Himalayan glaciers retreat

Posted: 15 March 2005

Himalayan glaciers are among the fastest retreating glaciers globally due to the effects of global warming, and this will eventually result in water shortages for hundreds of millions of people who rely on glacier-dependent rivers in China, India and Nepal, warns WWF, the global conservation organization.

A new WWF report - An Overview of Glaciers, Glacier Retreat and Subsequent Impacts in Nepal, India and China - reveals the rate of retreat of Himalayan glaciers accelerating as global warming increases. The report states that glaciers in the region are now receding at an average rate of 10-15 metres per year.

"The rapid melting of Himalayan glaciers will first increase the volume of water in rivers causing widespread flooding," said Jennifer Morgan, Director of WWF's Global Climate Change Programme. "But in a few decades this situation will change and the water level in rivers will decline, meaning massive economic and environmental problems for people in Western China, Nepal and Northern India."

Himalayan glaciers feed into seven of Asia's greatest rivers (the Ganges, Indus, Brahmaputra, Salween, Mekong, Yangtze and Huang He), ensuring a year-round water supply to hundreds of millions of people in the Indian subcontinent and China. As glacier water flows dwindle, the energy potential of hydroelectric power will decrease causing problems for industry, while reduced irrigation means lower crop production.

It is likely that the accelerated melting of glaciers will cause an increase in river levels over the next few decades, initially leading to higher incidence of flooding and land-slides. But, in the longer term, as the volume of ice available for melting diminishes, a reduction in glacial runoff and river flows is to be expected. In the Ganga, the loss of glacier meltwater would reduce July-September flows by two-thirds, causing water shortages for 500 million people and 37 per cent of India's irrigated land.

Nepal has an annual average temperature rise of 0.06°C per year. The report shows that three of Nepal's snow-fed rivers have shown declining trends in discharge. In China, the report shows that Qinghai Plateau's wetlands have seen declining lake water levels, lake shrinkage, the absence of water flow in rivers and streams, and the degradation of swamp wetlands. In India, the Gangotri glacier, which supports one of India's largest river basins, is receding at an average rate of 23 metres per year.

The report is released on the eve of a two-day ministerial roundtable of the 20 largest energy using economies in the world, including China and India, followed by a G8 meeting of development and environment ministers focusing on climate change and on Africa. Both meetings are hosted by the UK government in London from 15-18 March. WWF has sent a letter to participating ministers, stressing the need to recognize climate change as an issue that seriously threatens security and development prospects.

"Ministers should realize now that the world faces an economic and development catastrophe if the rate of global warming isn't reduced," said Jennifer Morgan. "They need to work together on reducing CO2 emissions, increasing the use of renewable energy and implementing energy efficiency measures."

More than half of humanity relies on the freshwater that accumulates in the snows and glaciers of mountains.