A measuring pole in front of the Mengke Glacier, which is currently being monitored by researchers from the Chinese Academy of Sciences. The glacier in north-west China is receding fast, and towns along an arid corridor have suffered floods and landslides caused by sudden rainstorms. Photo: The New York Times
todayonline.com
December 10, 2015
As glaciers increasingly retreat because of climate change, there are serious consequences
MENGKE GLACIER (China) — Over the years, Dr Qin Xiang and his fellow scientists at a high and lonely research station in the Qilian Mountains of north-west China have tracked the inexorable effects of rising temperatures on one of China’s most important water sources.
“The thing most sensitive to climate change is a glacier,” said Dr Qin, 42, as he slowly trod across an icy field on the Mengke Glacier, one of the country’s largest. “In the 1970s, people thought glaciers were permanent. They didn’t think that glaciers would recede. They thought this glacier would endure. But then the climate began changing, and temperatures climbed.”
Beneath Dr Qin’s feet, the cracking ice signalled the second-by-second shifting of the glacier.
The extreme effects predicted of global climate change are already happening in western China. Glacier retreat here and across the so-called Third Pole — the glaciers of the Himalayas and related mountain ranges — threatens Asia’s water supply. Towns and villages along the arid Hexi Corridor, a passage on the historic Silk Road where camels still roam, have suffered floods and landslides caused by sudden summer rainstorms.
Permafrost is disappearing from the Tibet-Qinghai Plateau, jeopardising the existence of plants and animals, the livelihoods of its people and even the integrity of infrastructure such as China’s high-altitude railway to Lhasa, Tibet.
The fact that Chinese scientists are raising alarms about these changes is a key reason that the Chinese government has been engaging fully in climate change negotiations in recent years. Another is the deadly urban air pollution, caused mostly by industrial coal burning, which resulted in Beijing’s first red alert over air quality on Monday.
China, which is the world’s largest emitter of greenhouse gases, pledged last year to begin lowering carbon dioxide emissions around 2030, and in Paris this month, President Xi Jinping reiterated his resolve to help slow climate change. There are no vocal climate change deniers among top Chinese officials.
In November, China released a detailed scientific report on climate change that predicted disastrous consequences for its 1.4 billion people. Those included rising sea levels along the urbanised coast, floods from storms across China and the erosion of glaciers. More than 80 per cent of the permafrost on the Tibet-Qinghai Plateau could disappear by the next century, said the report.
Temperatures in China are expected to rise by 1.3°C to 5°C by the end of the century, and temperatures have risen faster in China in the last half-century than the global average.
People across China are already feeling the impact. The most obvious devastation comes from flooding. The report said an increase in urban floods attributed to climate change has destroyed homes and infrastructure. From 2008 to 2010, 62 per cent of Chinese cities had floods; 173 had three or more.
“China is more prone to the adverse effects of climate change because China is vast, has diverse types of ecology and has relatively fragile natural conditions,” Mr Du Xiangwan, chairman of the National Expert Committee on Climate Change, wrote in the report’s introduction.
Last weekend, Chinese scientists released a separate report that said the surface area of glaciers on Mount Everest, which straddles the Tibet-Nepal border, have shrunk nearly 30 per cent in the last 40 years.
Vanishing glaciers raise urgent concerns beyond Tibet and China.
By one estimate, the 46,000 glaciers of the Third Pole region help sustain 1.5 billion people in 10 countries — its waters flowing to places as distant as the tropical Mekong Delta of Vietnam, the hills of eastern Myanmar and the southern plains of Bangladesh. Scattered across nearly 5.2 million sq km, these glaciers are receding at an ever-quickening pace, producing a rise in levels of rivers and lakes in the short term and threatening Asia’s water supply in the long run.
A paper published this year by The Journal of Glaciology said the retreat of Asian glaciers was emblematic of a “historically unprecedented global glacier decline”.
“I would say that climatologically, we are in unfamiliar territory, and the world’s ice cover is responding dramatically,” said Mr Lonnie Thompson, a glaciologist at Ohio State University who helped found a project to study climate change on the Tibetan Plateau. Across China, the surface area of glaciers has decreased more than 10 per cent since the 1960s, according to the climate change report. The report linked the expected water scarcity to national security, noting that “in the future, disputes between China and neighbouring countries on regional environmental resources will keep growing”.
The Qilian Range, on the northern end of the Tibetan Plateau, straddles three provinces and towers to 5,550m. Scientists here at the Mengke Glacier have been studying it from a permanent research station since 2007, one of about 10 major glacier research stations in China. The glacier is 9.7km long and covers nearly 21 sq km.
As it recedes more rapidly, floods here have become more frequent and more powerful. In July, the road to the research station flooded, with the waters rising more than 2m.
Mr Zhao Shangxue, who manages logistics here, said that he had to abandon his car and walk four hours to the station. “The glacier has always melted in the summertime, but now it melts even more,” he said.
A report by the research centre said the retreat of the Mengke Glacier and two others in the Qilian Range accelerated gradually in the 1990s, then tripled in speed in the 2000s. In the last decade, the glaciers have been disappearing at a faster rate than at any time since 1960. From 2005 to 2014, the Mengke Glacier retreated an average of 16.5m a year, while from 1993 to 2005, it retreated 7.9m a year.
As scientists such as Mr Qin study the glacier and the consequences of its retreat, towns and villages in the region are grappling with a worsening cycle of drought, sudden rainstorms and floods.
The town closest to the glacier, Shibaocheng, has been devastated by recent storms. Its 1,250 residents, mostly ethnic Mongolians, graze yaks, horses and sheep in high pastures below the glacier during the summer. In 2012, a sudden rainstorm set off flooding that destroyed about 200 homes. Nearly 14,000 animals were killed or lost.
“Old people here say they hadn’t seen such a flood in 50 or 60 years,” said Ms Gu Wei, the Deputy Mayor. She said rain mixed with hail came down for three days.
Scientists have no easy way to determine the exact relationship between the rainfall and the changes in the nearby glacier, said Dr Qin. “The retreat of glaciers of course has an effect on the climate and on rain patterns, but we can’t measure it,” he said.
South-east of Mengke Glacier, 290km away along the Hexi Corridor, Sunan County at the foot of the Qilian Mountains has experienced some of the region’s worst flooding. It is home to ethnic Yugurs and has flooded a half-dozen times since 2006.
Five years ago, at least 11 people died in floods and landslides. In July, heavy rains led to similar disasters in 13 villages, destroying more than 150 homes and causing more than US$6 million (S$8.5 million) of damage, said an official report.
“Floods in the Hexi Corridor are related to torrential rains and precipitation from fronts,” said Mr Wang Ninglian, a glaciologist at the Chinese Academy of Sciences. “It’s caused by climate change.” THE NEW YORK TIMES
