Saturday, November 2, 2013

Melting glaciers bring energy uncertainty

Javaid Laghari in Nature: Running 2,000 kilometres from east to west and comprising more than 60,000 square kilometres of ice, the Hindu Kush–Karakoram–Himalayan glaciers are a source of water for the quarter of the global population that lives in south Asia. Glaciers are natural stores and regulators of water supply to rivers, which, in turn, provide water for domestic and industrial consumption, energy generation and irrigation.

Ice cover is decreasing in this region, as for most glaciers in the world, as a result of global warming. Between 2003 and 2009, Himalayan glaciers lost an estimated 174 gigatonnes of water each year, and contributed to catastrophic floods of the Indus, Ganges and Brahmaputra rivers. Pollution is accelerating the melt. An 'Asian brown cloud', formed from the 2 million tonnes of soot and dark particles released into the atmosphere every year, mostly from India and China, warms the air and surface ice.

Seasonal meltwater serves as the main source of power for an increasing number of hydroelectric dams on the rivers served by the glaciers. But hydropower faces a difficult future in south Asia because of climatic, environmental and politico-economic factors. The region is starved of energy, and power shortages of up to 20 hours a day are stunting development. Importing oil and gas from the Gulf, Iran or Tajikistan is expensive or politically difficult. So countries are turning to indigenous hydroelectric power, and to other renewable energies such as solar and wind, for cheap, sustainable energy.

Hydroelectric power must play a part in south Asia's low-carbon energy future. But to be effective, governments around the Himalayas need to work together to measure and model glacier retreat, changing river flows and their impact on hydroelectric power generation. Political obstacles to dam construction and watershed management must also be overcome.

Glaciers feed thousands of miles of rivers in Pakistan. The largest, the river Indus, depends on glacial waters for half of its flow. But near the river's source, in mountains in the Indian-administered state of Jammu and Kashmir, the glaciers are thinning at an alarming rate of 0.7 metres per year. The Ganges and Brahmaputra rivers in India and Bangladesh are similarly threatened by glacial melting in the regions of their headwaters....

Durung Drung glacier and Nun-Kun twin peaks (7100m), Zanskar, Jammu & Kashmir, India, shot by BasinField, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

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