Trouble at Third Pole

Retreating at an alarming rate: The Khumbu Glacier, with Mount Everest in the background.   | Photo Credit: SUBEL BHANDARI

The Himalayas, which we Indians have considered invincible and unconquerable, have been noticeably impacted by climate change. The greater Himalayan region, called “ the roof of the world”, contains the most extensive and rugged high alti tude areas on earth. These are the largest areas covered by glaciers and permafrost outside the Polar regions and the area is now being called the Third Pole. The melt waters of this area drain through 10 of the largest rivers in Asia and the basins are home to more than 1.3 billion people. These water resources play an important role in global atmospheric circulation, biodiversity, rain-fed and irrigated agriculture and hydropower. With climate change happening, the most widely reported impact is the rapid reduction in glaciers which cause massive repercussions to livelihoods downstream.

Adverse impact

China and India are the two leading producers of rice in the world with most of the harvest coming from the Ganges basin, and the Yangtze and Yellow River basins. But with the spectre of climate change, the Stern report (2006) has said, “China’s human development could face a major U-turn by mid century unless urgent measures are taken to ‘climate proof’ development results.”

Himalayan Glaciers are receding faster today than the world average. According to scientists in China, in the last half of the 20th century, 82 per cent of the glaciers in Western China have retreated. On the Tibetan Plateau, the glacial area has decreased by 4.5 per cent over the last 20 years and over seven per cent over the last 40 years, indicating an increased retreat rate.

The scientists say the glacier retreat in the Himalayas results from precipitation decrease in combination with temperature increase. Glacier shrinkage will speed up if climatic warming and drying continues. In fact, the IPCC Fourth Assessment Report in 2007 states that in the coming decades, many glaciers in the region will retreat, while smaller ones will disappear altogether. So it is reasonable to conclude that with a two per cent increase by 2050, 35 per cent of the present glaciers will disappear and run off will increase, peaking between 2030 and 2050.

Disaster ahead

In Asia, climate change-induced glacial melt could seriously affect half a billion people in the Himalayan region, and a quarter of a billion people in China, people who depend on glacial melt for their water supply (Stern 2007). Perennial rivers like the Indus, Ganga and Brahmaputra are all fed by the unique reservoir formed by the 16,000 Himalayan glaciers. The current trends in glacial melt suggest that the low flow will become substantially reduced as a consequence of climate change (IPCC 2007a) The effect of this on food production will be catastrophic. The situation, say scientists, may appear to be normal for several decades; however when the shortage happens, it will happen abruptly with water systems going from plenty to scarce in a few decades. Finally, it is the poorest who will get hit.

The International Centre for Integrated Mountain Development (ICIMOD), Kathmandu, Nepal, has conducted ongoing studies on glacial lakes which have formed in the area left at the foot of the retreating glaciers. An inventory conducted by ICIMOD in 2009 identified 8,790 glacial lakes in parts of the Hindu Khush – Himalayas. “Around 204 of these lakes are considered to be potentially dangerous in that they are liable to burst their banks leading to what is known as a glacial lake outburst flood (GLOF). There have been approximately 35 GLOF disasters in Bhutan, China and Nepal in the 20th century,” says Syed Iqbal Husnain of TERI, who is India’s foremost glaciologist, during his talks in Kathmandu in September 2009. As he said, “Climate change has become a major issue in the Hindu Khush – Himalayan region as the mountain regions are particularly vulnerable.”

In some ways global challenges like climate change and poverty can be seen as great dividers — exposing the degrees of separation between people who can afford to cope and people who cannot. Hopefully COP 15 can look towards the world’s countries working together to reduce emissions irrespective of being developed or not. Also a scaling up of financial and technical support for both adaptation and mitigation by developed countries will go a long way in stemming the heating up of our planet.

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Printable version | Apr 14, 2021 2:42:38 PM | https://www.thehindu.com/sci-tech/energy-and-environment/Trouble-at-Third-Pole/article16886001.ece

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