In Mado, the "first county of the Yellow River", the 80-year-old governor of the county, Lapao, has been lamenting the "changes in the world", and he has witnessed more than two decades of changes in the county over the past 20 years.
From 1966 to 1984, Lahao served as governor of Mado County in Qinghai Province, the source of the Yellow River. 1979 to 1982, Mado was China's best pastureland, and jumped to become the country's richest county. Now, due to dramatic environmental changes, Mado is one of the nation's poor counties.
"Thirty years ago, because there was too much water from the Yellow River, the county was surrounded by wetlands, and Mado County relocated once." Lapao said, "Now it is facing a second relocation -- the groundwater level is dropping year by year, and drinking water has become a problem for the whole county."
Global warming is an important reason for the ecological deterioration of the source of the Yellow River and even the Yangtze River. This point, the old county governor Lapao can also find clues from his own life experience, "Now the climate is becoming warmer and warmer. In the past we had to wear thick cotton felt clothes in winter, but now we can survive the winter with a fleece jacket."
Warming climate causing glaciers to recede
Dr. Lu Anxin of the Institute of Cold and Arid Environments and Engineering of the Chinese Academy of Sciences said the temperature of the Tibetan Plateau will rise by 1.4 degrees Celsius in the next 25 years. If this climate change trend continues, the amount of water in the Yellow River's headwaters will be reduced by 50 percent within a decade or so. By then, it will be not just the herders in one area who will be in trouble, but the entire basin.
In June this year, Lu Anxin visited the source of the Yellow River, Mount Animachin, where Chinese and foreign glaciologists set up a glacier observation point 25 years ago. The doctor visually estimated that the glacier had retreated nearly 1 kilometer between the 25 years.
Mount Animachen is one of the four sacred mountains of the Tibetan people, and the mountain has nurtured snow and glaciers for millions of years. These glaciers account for 96 percent of the total glacier area in the Yellow River source area. Every summer, the snow and ice melt and merge into crystal thin streams, replenishing the water source for the Yellow River. Glaciers are very sensitive, even small temperature changes can cause changes in the glaciers, so by observing the glaciers over a long period of time, strong evidence can be obtained to prove the trend of climate change.
If we go by the predictions of the Hadley Center in the United Kingdom, by 2100, the temperature of the Tibetan Plateau will be 2-3.6 degrees Celsius higher than it is now. A rough estimate suggests that more than half of the glaciers in northwestern China will have completely disappeared by 2050.
Yao Tangdong, director of the Tibetan Plateau Research Institute of the Chinese Academy of Sciences, said global warming has reduced the area of China's glaciers by an average of 7 percent in the past 40 years, and that the annual meltwater runoff from glaciers is now equivalent to that of a Yellow River.
Yao said China's glaciers are concentrated in the western part of the country, and most of the glaciers in the high-Asia region centered on the Tibetan Plateau have been in strong retreat since the middle of the last century due to the warming of the climate, and some of the glaciers that were once advancing or stabilizing have turned backward as the warming of the climate intensifies.
Ice avalanches
In the long term, receding glaciers can cause the world's major rivers to become dry from their sources. And in the short term, climate change and glacier retreat can cause other disasters.
On Ruanshin's way to explore the glacier, many locals thought they were heading for a "big avalanche," the largest in the history of Mount Animachen on March 18, 2004, when more than 2,640 hectares of fall meadows were destroyed in an instant. The mountain's largest avalanche in history occurred on March 18, 2004, destroying more than 2,640 hectares of fall meadows.
At the site of the "avalanche", all the researchers were stunned: the lush green meadow was suddenly covered by a giant coal mine. Black rocks and gravel were scattered everywhere, underfoot, on the slopes and in the gullies, as if they had experienced a volcanic eruption. Lu Anxin came to an even more surprising conclusion, suggesting that this was not an avalanche, but an "ice avalanche". The rapid rise in temperature triggered the rapid melting of the glacier, different parts of the melting speed is different, so the pressure distribution of the entire glacier is extremely uneven. In addition, the steep geological features on the western side of Mount Animachen exacerbated the danger posed by the retreat of the glacier, which triggered the eventual collapse. The collapse was so powerful that the glacier, with its huge volume of snow and black moraine, tore down even part of the mountain. Fourteen months later, the aftermath of the shocking scene still haunts visitors.
However, the sliding glacier and moraine formed an ice dam of 5 kilometers horizontally and 3 kilometers vertically with an average thickness of 300 meters in the valley of the Qingshui, Quanlong, and Damachu rivers converging into the Qushuan River, blocking the river and forming a weir. Because of the constant recharge from upstream, the size of this lake is expanding every day; at the same time, the moraine dam, composed of gravel and glacial debris, is loosening every day. The dam itself is loose and porous, and the frozen portion of it is melting faster and faster due to rising temperatures and the impact of water waves, threatening to break at any time. Visible cracks could already be seen along the edges of the three prominent moraines, and the sound of cracking ice could even be heard. Small fragments of rock and ice continue to fall off the dam and slide into the lake. The lowest part of the dam is only 5 meters higher than the water surface, a burst of heavy rain or a steep rise in temperature caused by the accelerated melting can make this porous dam completely break. In July this year, the weir finally collapsed with a bang, and the river spilled out, washing away some houses and livestock, but fortunately causing no casualties.
Tundra no more
At 59 kilometers from Huashixia town, Dr. Lu Anxin raised his hand and pointed, "Look at that ditch! We are now in the tundra." In the source area of the Yellow River permafrost is very widely distributed, but the thickness is very thin. As a result, the perennial permafrost here is more susceptible to climate warming. Once a patch of subterranean ice melts, a trench forms on the surface. After that, the temperature balance of the surface soil is upset and the trench grows, with the sides melting faster and faster, creating what is known as a freeze-thaw slide.
Lu Anxin said the permafrost in the source area of the Yellow River has been receding on a large scale in the last 20 years, mainly in terms of higher average land temperatures, deepening of the active layer, and raising of the lower boundary of the permafrost.
At a fork in the road on National Highway 214, the team saw an abandoned dwelling. There was a courtyard in the center surrounded by 16 houses. All the walls were covered with cracks that were both long and deep, and some were even beginning to lean. The thawing permafrost had directly affected the strength of the houses' foundations, so the walls were tilting and cracking. Houses abandoned due to thawed and loosened foundations are everywhere in the region, even on the highways. Although the design and construction of roadbeds are well calculated and take into account the effects of various climatic conditions, they are not sustainable in the face of climate change. The permafrost under the ground is melting faster than one would expect, so the once flat and smooth asphalt road on top of the roadbed is now undulating like a wave, with the yellow line in the middle of the road being pulled in all directions, making it look quite funny, and jokingly referred to as a "dancing highway". Although Lu Anxin's expedition was well prepared for this, there was still a minor car accident. The government refurbishes the highways on the Tibetan plateau every year, with a major overhaul every three years, otherwise the roads would be a disaster.
At the same time, the falling water table is leading to degradation of vegetation and desertification and salinization of the land. The chain reaction triggered by the water crisis will eventually lead to large-scale land degradation and desertification in the Yellow River source area. In the hydrological cycle of the Yellow River source area, permafrost plays an important role, and the serious degradation of the deep permafrost caused by climate warming and temperature increase is irreversible. And a large amount of greenhouse gases will be released in the process, causing increased warming and triggering more serious permafrost degradation and glacier retreat. Such a vicious cycle seems to signal that mankind's unchecked development has driven itself into a dead end.
When the team set up camp at the 4,200-meter-high Mount Animachen, they came across Sobo, who lives here. Sobao is a Tibetan boy, 35 years old, with curly hair and a clear gaze. His first words were: "Please don't litter, please don't defile the holy water. Without the holy water, all living things here will wither away." The "holy water" he was talking about was the Yellow River.
But just not littering won't save this "holy water". Global warming is caused by the huge amount of greenhouse gases emitted by monstrous industrial development. "Only if the countries of the world take up their obligations, industrial development to do 'sustainable', reduce greenhouse gas emissions, in order to *** with the response to this crisis." An expert said