Li Zhongqin, a scientist who heads the Tianshan Mountains Glaciological Station of the Chinese Academy of Sciences, makes a seasonal hike toward the top of a glacier in the Tianshan mountains at the end of every summer to measure the thinning of the glacier, reports NPR. “We come up here each month to check it, to see how fast the glacier’s melt. Each year, the glacier is 15 feet thinner,” Zhongqin told Morning Edition’s Rob Schmitz.
Though the government has banned tourism on the glaciers in an effort to reduce the impact of pollution, global carbon emissions are a bigger threat. The melting glaciers are a big problem because not only are the glaciers the source of water for millions of people, but they also impact agriculture in drier areas like the city of Turpan that sits on the edge of Taklamakan Desert. Though dry, the region is an agriculture powerhouse which depends on the water arriving through meltwaters that flow through thousands of miles of underground tunnels called karez, an ancient irrigation system, now slowly drying up.
GlacierHub recently reported on the severity of drought in Xinjiang, and it’s uncertain future. This Photo Friday view photos of the slowly disappearing glaciers. Read more here.
In a recent paper in Science of The Total Environment, a team of Chinese researchers created a model of the Urumqi No. 1 catchment in Xinjiang, China, and made a surprising discovery. As they sought to estimate the effects of global warming on glacier thinning, retreat and local supply of water resources, they found that the glacier is expected to reach “peak water,” with runoff shrinking by half of its 1980 extent in the next 30 years. The glacier will also lose approximately 80 percent of its ice volume.
As glaciers shrink, runoff increases (with more melting) but then decreases thereafter when the size of the glacier has permanently decreased. Peak water, or the tipping point of glacier melt supply, when runoff in glacier-fed rivers reaches the maximum, is estimated to occur around 2020. This phenomenon shares its concept with the term “peak oil,” which refers to the hypothetical point in time when the global oil production rate will reach maximum capacity. Thereafter, oil production will only decline.
In contrast to peak oil, glacial reserves can be estimated with a higher certainty. Annina Sorg, an independent researcher with expertise in geomorphology, geography and climatology, explained the concept to GlacierHub. “Peak water for a catchment can be assessed with quite good precision if the past climate and glacial volume loss are well known and if reasonable climate models are being used,” she said. This is because, unlike oil, consumption of glacier meltwater does not have a direct impact on glacial melting. Glaciers will continue to melt no matter if the demand for glacial meltwater is high or low.
“Peak water is an important aspect of glacial impact of hydrology, and the term absolutely makes sense,” Matthias Huss, a senior lecturer from the University of Freiburg, expressed in an interview with GlacierHub. “After peak water, annual runoff sums from glaciers will be steadily decreasing, which might cause problems with water availability.”
Huss’s team recently published a paper on the first complete global assessment of when peak water from glaciers will occur. Huss believes the smaller scale study on the Urumqi glacier uses a very similar approach as he did for all 200,000 glaciers globally but with more accurate data for calibration and validation to fit the local context. Both studies also yield consistent findings.
In the arid regions of Central Asia, meltwater from glaciers determine streamflow. Glaciers are not only valuable water sources for the communities around rivers, but can also serve as buffers against droughts during dry periods.
“Conditions are ‘good’ before peak water— we even have more water than in the case of balanced glacier mass budgets. This water can be used for irrigation or hydropower production. However, after peak water, less water is available, most importantly in the summer months, which might have considerable impact on water resource management,” Huss warned.
The story is also more complex in a broader context. Whether water shortage is experienced due to glacier recession strongly depends on the climate regime. In general, glaciers play a more important role when summer climates are dry, as in the case of Xinjiang. Peak water also strongly varies with glacier size, with larger glaciers experiencing later peaks than smaller glaciers.
“As Urumqi Glacier is a relatively small glacier, it might not be fully representative for regional peak water, which is governed by the larger glaciers,” Huss explained.
Still, Sorg holds the view that the abundance of meltwater before peak water “might slow down a society’s attempts to elaborate mitigation measures, which would be needed to handle the second period of decreasing meltwater runoff.”
In the case of Xinjiang, runoff from glacier melting will likely experience a dramatic decrease from 2020 to 2050, post peak water. The east and west branches of Urumqi No. 1 Glacier also have different responses to climate change. By the end of the 21st century, as compared to 1980 rates, the area extent and ice volume of the west branch could decrease by up to 58 and 82 percent, respectively. While at the east branch, glacier area could shrink by 95 percent, losing about 99 percent of its ice volume.
“In my opinion, it is important to spread the term ‘peak water,’ also in popular media, not science alone. It draws awareness to the point that the depletion of glacial reserves is not a continuous process like emptying a bathtub,” Sorg told GlacierHub. Rather, peak water is a period of abundance that Sorg thinks is probably not appreciated enough and is taken for granted.
Sorg concluded with a somber reminder. “After peak water, the days of plenty are over— at least in respect to glacial meltwater availability,” she said. As Xinjiang is very dependent on its glaciers, mitigation measures are required to adapt to glacier mass changes for long-term water security in the region.
Insights into Bárðarbunga Volcano from the Holuhraun Rifting Event
From Advancing Earth and Space Science: “The two weeklong rifting event at Bárðarbunga volcano in 2014 led to the Holuhraun eruption, which produced 1.5 km3 of lava and was the largest in Iceland in over 200 years. Predicting when and where an intrusion will lead to eruption requires detailed knowledge of the underlying stress field… Modeling of the 2014 Bárðarbunga rifting event therefore not only yields insights into the event but also provides a window into undetected volcanic activity in the past.”
Find out more about the geology behind one of the biggest eruptions on a glacier-covered volcano here.
Distribution of Black Flies in the Andes During El Niño
From ScienceDirect: “Vector ecology is a key factor in understanding the transmission of disease agents, with each species having an optimal range of environmental requirements. Scarce data, however, are available for how interactions of local and broad-scale climate phenomena, such as seasonality and the El Niño Southern Oscillation (ENSO), affect simuliids (Black Flies). We, therefore, conducted an exploratory study to examine distribution patterns of species of Simuliidae along an elevational gradient of the Otún River in the Colombian Andes, encompassing four ecoregions. Species richness and occurrence in each ecoregion were influenced by elevation, seasonality, and primarily the warm El Niño and cool La Niña phases of the ENSO. The degree of change differed among ecoregions and was related to physicochemical factors, mainly with stream discharge.”
Read more about the distribution of black flies based on the climatology of the Andes Mountains here.
Glacier Retreat of the Tian Shan and Impact on Urban Growth
From IOP Earth and Environmental Science: “The retreat of mountain glaciers, notably in high Asia, provides evidence for the rise of global temperature. Analyses of satellite remote sensing data combined with the ground observations reveal a 37.5% decline of glaciered area from 1989 to 2014 in No.1 Glacier, the headwaters of the Urumqi River basin, Chinese Tian Shan, which could be linked to increased summer melting. We suggest that the decline of glacier area is driven primarily by summer melting and, possibly, linked to the combined effects of the global rise in temperatures and black carbon/CO2 emission from coal-fired power plants, cement plants and petroleum chemical plants from the nearby Urumqi regions.”
Discover more about the glacier melting in Tian Shan Mountains and its impacts here.
In February 2016, the government in China’s Xinjiang Uyghur Autonomous Region announced that tourists would no longer be permitted to stand atop its retreating glaciers. According to the memo, tourism was a direct cause of glacial retreat. China is home to 46,377 glaciers, and the government has a particular reason to be concerned with the state of its glaciers in this region: comprising 1/6 of China’s land mass, Xinjiang is home to 18,311 of them.
The Tian Shan Glacier No. 1, which has existed for a reported 4.8 million years, is expected to disappear within 50 years. Though the glacier is only accessible via roads that would give Indiana Jones pause, it remains a popular tourist destination. Josh Summers has been living in Xinjiang since 2006 and runs a well-regarded travel blog that provides hard-to-find information for foreign tourists interested in visiting the far-away region. Today, we travel to Xinjiang to see this glacier before it disappears.
Watch Josh’s drive from Urumqi to Tian Shan Glacier No. 1 via ‘Highway’ 216: