Glacier Retreat in the Third Pole

Standard Page - 2006-01-06
Climate change is causing glaciers to melt throughout China, especially in the Qinghai-Tibetan Plateau, with devastating consequences for the billions of people who depend on them.

Climate change is causing glaciers to melt throughout China, especially in the Qinghai-Tibetan Plateau, with devastating consequences for the billions of people who depend on them.

The Qinghai-Tibetan Plateau is unique in the world, not only for its extraordinary isolated landscapes. This remote region of soaring peaks, high steppes and glaciers cover a million square miles – about a quarter of China's land surface. Altitudes are uniformly high, averaging 4,000 meters (13,000 feet) above sea level. It's home to the Himalayas, including Mt. Everest, and many of the highest mountains in the world.

A Greenpeace activist holds up a photo of the Middle Rongbuk Glacier taken in 1968 to compare it with the present. The glacier has deteriorated and retreated by 2km in just under 40 years.
A Greenpeace activist holds up a photo of the Middle Rongbuk Glacier taken in 1968 to compare it with the present. The glacier has deterioriated and retreated by 2km in just under 40 years.

The plateau is also home to the largest concentration of ice outside the north and south poles – including 47% of China's glaciers – earning it the name of the "Third Pole". As such, the Qinghai-Tibetan Plateau is critical to regulating water supply in Asia, as well as local climates and ecosystems. Glaciers here are the source of the major rivers in Asia, including the Yangtze, Yellow River, Mekong, Ganges and Indus.

But its glaciers are now melting at unprecedented rates. That melting is accelerated for the Himalayan glaciers by black carbon, which is the soot produced by cooking with biofuels such as wood, crop waste, and dung. Black carbon settles on to the glaciers, darkening the ice and snow and causing them to absorb more heat. As a result, the glaciers melt earlier in the summer, and for longer periods of time.

Impacts of Glacier Retreat

Retreating glaciers means that there is less water for the Tibetan villagers and nomads that live in the region. It also means less water for the rivers fed by the glaciers, and thus less water for the billions of people who depend on the Yangtze, Yellow, Ganges and Indus.

79-year-old Ben Luo once owned 1,400 sheep and 140 yaks, but has lost her livelihood due to drought-degraded grassland. Now she lives off government rations and has no income.

The warming Himalayas also has wider implications for the global climate – it may, for example, weaken the Indian monsoon, which will in turn have other effects on worldwide rainfall patterns.

In 2007, Greenpeace undertook an expedition to Mt. Everest to investigate the effects of climate change. We documented the retreating Rongbuk Glacier, and spoke to lamas at the local monastery about the increased incidence of drought in recent years.

In 2005, Greenpeace also commissioned a report with Chinese university scientists on climate change's impact on the glaciers at the source of the Yellow River. The study, "Yellow River at Risk," found that the region had lost 17% of its glaciers in the last 30 years, and that the ice now melted at rates 10 times faster than in the previous 300 years. It identified a domino chain of environmental effects, including dried lakes, advancing deserts, subsidence from melted permafrost, soil erosion and endangered species such as the Tibetan lynx and snow leopard.

A nomadic family risks losing their livelihood as a result of desertification of their traditional grasslands. Eling Lake, Madou county, Qinghai.

Glacial Floods

As glaciers melt and retreat, the melting water builds up into lakes, dammed up by rocks and other debris left behind by the glacier. With rising temperatures, most meltwater lakes are growing at unprecedented rates and even expanding to join adjacent lakes. This results in precariously balanced lakes, teetering on the brink of overflow. A sudden earthquake, avalanche, landslide or other disruptive vents can rupture the dams, resulting in a massively destructive flood. This is what scientists call a GLOF, or a Glacial Lake Outburst Flood.

A glacier melt lake, formed by the deterioration of the Middle Rongbuk Glacier, south of Everest Base Camp.

GLOFs can be highly destructive: just imagine the effect of an inland tsunami of ice-cold, debris-filled water surging down inhabited valleys. Many Tibetan villages and nomads live in these high valleys, and they are ill prepared to deal with such flash floods.

One of China's most infamous GLOFs occurred at Sangwang Lake in 1954. Over 300 million cubic meters of debris-filled water flash-flooded the Nianchu River valley. The flow buried the valley in debris three to five meters thick. An estimated 691 people lost their lives and 16,000 more lost crops, land, houses, and livestock.

Permafrost – No Longer so Permanent?

According to the UNEP, the temperatures of the permafrost of the Qinghai-Tibetan plateau have warmed faster than anywhere else in the world except for the poles. A layer of earth that's completely frozen for part of each year, permafrost traps water in the topmost layer of soil, allowing plants to grow at altitudes that would otherwise be too harsh for life. The loss of permafrost would endanger the fragile ecosystems in these alpine regions, which support endangered Tibetan antelope.

Global Melting

The Qinghai-Tibetgan glaciers are not alone. All over the world, on every continent, glaciers are retreating, from the Pamirs in Pakistan to the Austrian alps, from New Zealand to Canada to the Andes in South America. And their retreating will have the same dangerous impacts on water supply, ecosystem balance and climate.

Glacial melt is like the canary in the mine; it is up to us to heed the warning on climate change and decide to take action.

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