Asia’s High Glaciers Protect Communities from Drought

A recent study in Nature by Hamish Pritchard, a glaciologist at Cambridge University and researcher for the British Antarctic Survey, shows that the high mountains of Asia, including the Himalayas, the Hindu Kush, and Karakoram, are being greatly affected by global warming. In some areas of the Himalayan region, for example, temperatures have risen faster than the global average. From 1982 to 2006, the average annual mean temperature in the region increased by 1.5 °C, with an average increase of .06 °C per year, according to UNEP. Even though studies on the high mountains of Asia are incomplete, it is believed that the mountains will lose half of their ice in the next 30 years.

Farmers in Pakistan are shifting from wheat to cope with the droughts (Source: Muhammad Darjat/Google Images).

This glacial loss has consequences for Asia as the glaciers provide an important ecosystem service to 800 million people by acting as a regional buffer against drought and providing summer meltwater to rivers and aquifers. If the glaciers in the eastern and central Himalayas disappear by 2035, the ecosystem service protecting against drought would be lost. Despite the fact that glaciers can promote drought resiliency, the surrounding areas would be particularly vulnerable to water scarcity because the glaciers will not supply enough meltwater to maintain the rivers and streams at adequate levels.

Lack of water could lead to devastating food shortages and malnutrition, further impacting the economy and public health. Based on a projected estimate of glacier area in 2050, it is thought that declining water availability will eventually threaten some 70 million people with food insecurity. Droughts in the Himalayan region have already resulted in more than 6 million deaths over the past century. Glacier loss would only add to drought-related water stress in the region, impacting a surrounding 136 million people.

In an interview with GlacierHub, Pritchard explained, “Without these glaciers, particularly in the Indus and Aral, droughts would be substantially worse in summer than they are now, and that could be enough to drive conflict and migration, which becomes a regional and potentially global issue. It could result in social instability, conflict, and migrations of populations.”

According to Pritchard’s research, the high mountains of Asia supply 23 cubic kilometers of water downstream every summer. If the glaciers were to vanish, the amount of water during the summer would decrease by 38 percent in the upper Indus basin on average and up to 58 percent in drought conditions. The loss of summer meltwater would have its greatest effects on the municipal and industrial needs of Pakistan, Tajikistan, Turkmenistan, Uzbekistan and Kyrgyzstan, with water stress being classified as medium to extremely high. For example, the Indus River, which has one of the world’s largest irrigation networks, is Pakistan’s primary source of freshwater. About 90 percent of Pakistan’s agriculture depends on the river and much of the world’s cotton comes from the Indus River Valley. Additionally, decreased meltwater would further affect upstream countries such as Kyrgyzstan, Tajikistan and Nepal that rely on hydropower. The Toktogul hydropower plant and four smaller plants downstream produce almost 80 percent of Kyrgyzstan’s electricity.

An irrigation system in the Indus basin in Pakistan (Source: GRID Arendal/Creative Commons).

Pritchard presents data that show how much the glacier meltwater contributes to different regions within Asia during drought. Some areas, such as the Aral Sea, rely exclusively on the glacier water during the drought months. The glaciers provide meltwater when rainfall is minimal or nonexistent under drought conditions because glaciers store precipitation for decades to centuries as ice, which then flows to lower altitudes when melting in the summer. Twila Moon, a postdoctoral research associate at the U.S. National Snow and Ice Data Centre in Boulder, Colorado, recently discussed the consequences of global glacier volume loss on populations worldwide in Science magazine. “Rising seas, to which melting ice is a key contributor, are expected to displace millions of people within the lifetime of many of today’s children,” she stated. “This loss of Earth’s land ice is of international concern.”

As temperatures continue to rise, the surrounding regions will begin to lose their source of water for food, agriculture and survival. Due to inadequate scientific studies and evidence, the trends and status of glaciers in the Himalayas and other ranges are not being sufficiently observed and recorded. A lack of adequate monitoring of the glaciers means political action to adapt to the foreseen changes will be limited. More communication between the scientific community and policymakers is needed to relay knowledge about the impacts of changes in glaciers on the region’s hydrology, environment and livelihoods.

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