Introduction
The Qinghai-Tibetan Plateau is a 2,500,000 km2 region in southwestern China and northeastern India with an average elevation above 4,500 meters. It is also known as the "Third Pole" or the "Roof of the World" and contains the largest amount of ice and permafrost outside of the poles (Zhou and Zhang 2021; You et al. 2021; Yao et al. 2018). The Qinghai-Tibetan Plateau is home to over one million nomadic pastoralists, known as drokpa, that use the plateau's alpine grasslands as rangelands for livestock. Drokpa are extremely vulnerable to climate change as they do not have many alternatives if pastoralism becomes untenable in the future (Feng and Squires 2020; Levine 2019; Isom 2011).
The Qinghai Tibetan Plateau has warmed 1.23°C (2.21°F) between 1961 and 2015, with most warming occurring since the 1980s (You et al. 2021). The current rate of warming of 0.3°C every decade is almost twice the average global rate of 0.19°C every decade; the above average rate of warming is a climatic phenomenon called Tibetan amplification (You et al. 2021; Gao et al. 2021). The region is projected to warm between 1.2°C to 5.6°C compared to the 1986 historical average, (You et al. 2021). The rapid warming of the region is the underlying cause of most climate associated hazards drokpa communities are facing today.
Water Tower of Asia
The glaciers of the Qinghai-Tibetan Plateau are the primary freshwater source for 1.4 billion people, from drokpa communities to larger population centers throughout China and South Asia. Their meltwater feeds some of the largest rivers in Asia including the Yangtze, Brahmaputra, and Ganges. However, rising temperatures are accelerating glacial loss, threatening regional food and water security (Zhou and Zhang 2021; Zhang et al. 2021; Yao et al. 2019).
Hazards
Changing Precipitation
Since 1960, average rainfall has increased by 12.7%, which has led to the subsequent increase of glacial lake size by 20% (Hua et al. 2021; Zhang et al. 2020). However, certain regions of the plateau are experiencing a decrease in average precipitation compared to the historical average, contributing to the desertification of grassland ecosystems (Yang et al. 2018). Average winter precipitation and the proportion of winter precipitation that falls as snow is also decreasing (Bibi et al. 2018). Despite a decrease in days with snow since 1991, the frequency of extreme snowstorms, known locally as kengschi, has increased (Feng and Squires 2020).
Glacial Melt
Lower amounts of meltwater from montane glaciers threatens food and water security as glacial melt is the primary source of water for local communities. Most local sedentary communities rely glacial melt for agricultural irrigation and drokpas need a constant supply of water for their livestock from rivers or glacial lakes (Zhang et al. 2021; Feng and Squires 2020). The timing of surges in glacial melt will also change, with glacial runoff expected to strengthen in winter, weaken in the summer, and peak earlier in the spring regardless of future emissions reductions (IPCC 2019). Air pollution from neighboring countries, particularly India, also increases the danger of glacial loss. Mercury, a potent neurotoxin, is produced by regional air pollution and settles and accumulates on glaciers. As glaciers melt, mercury contaminates aquatic ecosystems and drinking water supplies threatening the health of wildlife, livestock, and people (Sun et al. 2018).
Breaking Ice
Glacial lake outburst floods (GLOFs) are violent and sudden floods caused by the breaking of ice dams on glacial melt rivers (Allen et al. 2019). Glacier and permafrost melt are expected to increase the number of glacial lakes and destabilize mountain slopes, increasing GLOF risk (Zhang et al. 2022; IPCC 2019; Allen et al. 2019). Increased precipitation brought on by warmer temperatures will also increase GLOF risk as they are often triggered after heavy rainfall (Zhang et al. 2020; Allen et al. 2019). Drokpas' physical infrastructure is threatened by GLOFs as their houses could be easily destroyed in a violent flood (Zheng et al. 2022; Allen et al. 2019).
Permafrost Melt
The Qinghai-Tibetan Plateau contains the largest amount of high elevation permafrost in the world and the largest amount of permafrost outside the Arctic, covering 67% of its land area (Gao et al. 2021; Wang et al. 2020; Yang et al. 2018). The area of thawed permafrost in the Qinghai-Tibetan Plateau increased by a factor of 40 between 1969 and 2017 with 40% of that thaw occurring since 2004 (Gao et al. 2021). Permafrost area has shrunk by one fifth since the 1960s (You et al. 2021). Melting permafrost threatens human infrastructure and increase disaster risks from landslides and GLOFs (IPCC 2019). It has also lowered water tables in grasslands, reducing biodiversity and accelerating desertification (Yao et al. 2019; Yang et al. 2018).
Desertification
Grassland ecosystems cover 65% of the plateau and are rapidly drying with increasing temperatures (Li et al. 2020; Wang et al. 2020). 82%-86% of grasslands have been degraded by the loss of soil moisture from permafrost melt and decreased photosynthetic activity brought on by drier conditions (Yang et al. 2018). Warmer temperatures increase evapotranspiration, which reduces soil moisture and the amount of water available to plants, promoting desertification (Chen et al. 2020). Overgrazing of grasslands by livestock is also exacerbating climate induced desertification (Li et al. 2020).
Changing Ecosystems
Both Tibetan amplification and the sensitive nature of alpine ecosystems and human communities puts the Qinghai-Tibetan Plateau at extreme risk (You et al. 2021; Zhou and Zhang 2021). Terrestrial species are expected to undergo significant shifts in their habitat ranges with warming temperatures, greatly altering provisional ecosystem services and ecological community structure (IPCC 2022; Hua et al. 2021). Lowland species will move upwards, pushing alpine species towards extinction as their habitat range shrinks (IPCC 2019). Many species, including the goa and snow leopard, as well as the historical growing seasons of plants are endangered by climate change (Bibi et al. 2018).
Exposure
Drokpa communities are exposed to climate change through their geographic location and subsistence lifestyles (Feng and Squires 2020; Zhang et al. 2018). Drokpas move seasonally with their herds to provide optimal grazing land for their livestock. They are reliant on the materials and money that their livestock provide for survival, making any disruption to their nomadic pastoralist way of life potentially devastating (Levine 2019). The location of the Qinghai-Tibetan Plateau in or near heavily polluted countries, such as India and China, has also made drokpas more vulnerable to mercury pollution in glacial melt (Sun et al. 2018). The dependency of drokpas on their surrounding environment has made them acutely aware of the impacts of climate change on their daily lives as well as the grassland ecosystems they inhabit (Zhang et al. 2018).
Vulnerabilities
Glacial/Permafrost Melt:
- Rising temperatures are reducing water availability for livestock, drying out grasslands, and decreasing the quality of grazing land (Feng and Squires 2020).
- Use of glacial melt streams as a water source for both livestock and people increases vulnerability to irregular water availability and mercury poisoning (IPCC 2019; Sun et al. 2018).
- Permafrost melt is also decreasing the amount of available forage for livestock by accelerating desertification across the plateau (Yang et al. 2018).
Ecosystem Change:
- Increased competition with wildlife as the habitat ranges of wild species shift (Ren et al. 2021).
- The changing grassland growing season is altering the timing of when drokpas move their herds (Bibi et al. 2018).
Changing Climate:
- The increasing frequency of kengschi, and rain on snow events also pose a serious threat to drokpas. Past kengschi have caused mass morality of livestock (Feng and Squires 2020).
- Rain on snow events cover grasslands in a layer of ice and snow, which prevents livestock from grazing (Feng and Squires 2020).
- The yaks drokpas raise are not adapted to warmer temperatures, forcing them to stagnant bodies of water to reduce heat stress, which increases their susceptibility to waterborne parasitic infections (Ren et al. 2021).
Desertification:
- Increased temperatures have increased drokpas' vulnerability by degrading the grasslands their herds depend on, decreasing the quality of forage for livestock (Chen et al. 2020; Feng and Squires 2020; Yang et al. 2018)
The future of the Qinghai-Tibetan Plateau will be one of rapid climatic and ecological change for drokpas. But adapting to such dramatic changes is possible, and if done correctly will allow drokpas to remain in their historic homeland for centuries.
Millenia of Tradition
Pastoralism on the Qinghai-Tibetan Plateau is believed to have developed between 8,800 and 4,000 years ago (Isom 2011). Drokpas still raise herds of domestic sheep, Tibetan yak, and Bactrian camels today, despite facing government persecution since the mid 20th century (Feng and Squires 2020; Isom 2011). Drokpa communities have recently diversified their livelihoods to include the collection of the medicinal caterpillar fungus Ophiocordyceps sinensis and running restaurants or inns for the developing tourism industry (Hu et al. 2018, Hopping et al. 2018).
Adaptation and Resilience
Drokpas adapt to climate change in several ways:
- Build future infrastructure on land not containing permafrost to prevent future damage from permafrost thaw (Ni et al. 2021).
- Improve irrigation techniques and soil conservation practices to promote water security (IPCC 2022).
- Educate drokpas about climate change (Wang et al. 2020; Gongbuzeren 2018).
- Build early warning systems for GLOFs, kengschi, and changing precipitation patterns (Wang et al. 2020; Gongbuzeren et al. 2018).
- Limit the size and type of livestock herds to mitigate grassland desertification and vulnerability to kengschi (Wang et al. 2019; Gongbuzeren 2018).
- Adopt grazing policies including adjusting the start and end dates of the farming season, rotating rangelands, and even communalizing pastures to slow desertification (Wang et al. 2020).
- Invest more in protected areas and national parks to promote ecotourism and alternative livelihoods to pastoralism (Gongbuzeren 2018).
However, the remoteness of the Qinghai-Tibetan Plateau and traditional nature of drokpas’ lifestyles makes many of these changes difficult or unlikely to be adopted (Wang et al. 2020, Gongbuzeren 2018). Adapting to climate change is essential for the future survival of drokpa communities on the Qinghai-Tibetan Plateau. Failing to do so would not only inflict economic and social harm on current communities, but fundamentally alter their traditional way of life for generations to come.
About the Author
Andrew Miller graduated from St. Lawrence University in 2023 with a combined major in Biology and Environmental Studies and a minor in Government. He decided to write about the Qinghai-Tibetan Plateau for Jon Rosales' Adapting to Climate Change course because of his interest in the impacts of climate change on alpine communities and ecosystems. After attending and speaking at a UN conference on freshwater scarcity in 2019, Andrew is interested in pursuing a career in environmental policy with the UN or scientific research on global environmental change.
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