By Linden Ellis
The Tibetan Plateau, whose glaciers supply water to some 40 percent of the world's population, is a climate change hotspot that has experienced a 1 degree Celsius temperature rise in the past decade alone. The 40,000+ glaciers in China's Himalayas are in rapid retreat, posing grave environmental and human health threats—most critically the prospects of catastrophic water shortages. China's foremost glacier scientist, Yao Tandong, predicts that China's glaciers will disappear by 2050, while the UN Intergovernmental Panel estimates they may be gone as early as 2035. At this co-sponsored China Environment Forum and Asia Society Northern California meeting, Isabel Hilton (chinadialogue) and Julia Klein (Colorado State University) addressed the impact of climate change on the vulnerable ecosystems and communities in the Chinese Himalayas and discussed current efforts to mitigate threats to the melting glaciers.
Mysterious Melting Mountains
The Himalayan glaciers are surprisingly under studied due in part to their forbidding terrain. In the mid-1990s, glacier scientist Lonnie Thompson was the first to drill ice cores in the Himalayas and he has subsequently been training the current generation of glacier scientists in China. Thompson's research catalyzed a new interest within the scientific community to study climate impact trends in the Himalayas. On the lower slopes of these mountains, the glaciers have already disappeared as the global rising temperature trends are more acute at higher altitude. Local pollution from "Asia's Brown Cloud" also covers the region and is further raising temperatures. The combination of these affects is melting the Himalayan glaciers—the largest body of ice outside the poles—at about 7 percent annually.
Water scarcity is an existing problem in China, particularly northern China where the Yellow River does not reach the sea for much of the year. Beijing is currently undertaking a massive water transfer project to bring water from the Yangtze River to the dry north where per capita freshwater resources are one-tenth the global average. Solving water scarcity with major engineering projects is not new and has in fact directly affected China's glaciers. During the Great Leap Forward in the 1960s, the Chinese government targeted glacier water to achieve a tripling of agricultural production in dry Xinjiang Province. In the 1960s ethnic Hans—convicts, reeducated youth, and famine refugees—moved into Xinjiang military colonies and farming communes with the task to "make the desert bloom." Although space was plentiful, water was not. To supply more water, coal dust was spread from airplanes over the glaciers to speed melting. Some planes also bombed the glaciers to break them up. This "battle" against the glaciers brought tremendous increase in water to Xinjiang and other provinces downstream. Today, the glaciers in China no longer need human intervention to melt as coal dust is spread by air pollution and global CO2 emissions are increasing temperatures in the region. Notably, in Xinjiang, water-intensive activities—such as golf courses and cotton growing—have continued to develop as part of a larger development campaign to stimulate economic growth in the western China.
When glaciers melt rapidly, runoff begins to accumulate causing unstable lakes to build up on the glaciers. When the lakes become too heavy these natural barriers burst and create floods—essentially becoming mountain tsunamis—that devastate the people, infrastructure and environment below. These huge runoff lakes are particularly dangerous in earthquake prone areas like western China. Imja Lake, near Mount Everest on the Nepalese side of the Himalayas, did not exist in the 1960s. Now it grows by 74 meters a year in an earthquake zone posing a threat to the lower regions.
Development of Conflict
Risk of floods in the short term and the complete disappearance of the water supply in the future are major concerns for the Tibetan Plateau, yet conflict over scarce water adds another human security concern. About 2.5 billion people rely on water originating from glaciers in the Himalayas and disputes have already erupted in many communities.
The Gangotri Glacier in India, which is the main water source for the 500 million people living in the Ganges River Basin, has been shrinking by 23 meters a year. This glacier has been receding for at least 100 years, but the process has doubled in speed in the last few years. Bangladesh, at the Ganges River Delta, is the most vulnerable to flooding and sea-level rise. Recently, the flow of the Ganges River has increased as the glaciers melt faster, exacerbating the affects of annual cyclones and tsunamis.
Other tensions and armed conflicts already exist in the region. Currently, the Indian government has invested in building a wall to prevent flood refugees from Bangladesh from entering India. Isabel Hilton speculated that the Ganges River Delta is potentially the first area of climate change-related conflict, as the region has a history of solving crises with armed warfare. Climate change and melting glaciers are already an irreversible process and the only peaceful solution to inevitable water conflicts is for countries to build sustainable transboundary agreements on water management. Such agreements will facilitate needed adaptation efforts to conserve and share diminishing water supply fairly and adapt to shortages through science and technology.
Adapting Policy on the Tibetan Plateau
The nomadic herding communities in Tibet rely on the careful, interdependent network of plants and animals to survive on the plateau. Domestic animals provide meat, dairy, cloth for clothing and tents, and dung for fuel. There is a tight coupling between the natural environment and communities, and both are very vulnerable to climate change. Although the warming trend varies even within the Tibetan Plateau, ice cores indicate that the last 60 years have been the warmest on the plateau in the entire record.
As the plateau warms, the grasslands have also been changing. Places where grass was covered with snow all year round are now available for grazing during the summer months. In addition to warming, however, policies have been changing on the plateau. Over the past ten years the Chinese government has been encouraging or even requiring nomads to fence their land and live in communities. In 2003, the Chinese government began a policy of converting pasture to grassland in western China to prevent desertification and soil erosion, which has forced smaller areas of land to support an increasingly high density of grazing animals.
These policies to limit grazing are based on the belief that the Tibetans are overgrazing the rangelands leading to land degradation. Julia Klein—who a decade ago began studying grazing and ecosystem health in the grasslands of Tibet—pointed out that there is little science to back up these policies and many other factors could be contributing to grassland degradation.
In one study, Klein's team created mini greenhouses to increase the temperature on the grass and prevent animals from grazing on those sections. What her research found was that warming had a profoundly negative affect upon the vegetation. Specifically, warmer temperatures favor shrubs and less vegetation diversity, which lowers the carrying capacity of the grassland, meaning that it would be less able to recover from trauma such as a strong storm or overgrazing.
Changing Local Ecosystems
The study indicated the shrubs that thrived under warming conditions are less nutritious than meadow vegetation and yak do not like to eat them. In order to adapt to rising temperatures, pastoralists may have to change their herds from yak to sheep. Yet, yaks are a part of Tibetan identity and culture, as well as an economically valuable livestock. Medicinal plants, which are an increasing source of income for Tibetan pastoralists have also declined with warmer temperatures. A somewhat surprising discovery in the study was that while warming decreases both nutritious plants for livestock and medicinal plants, grazing seems to mitigate the affect. In short, grazing animals can potentially help the ecosystems better adapt to the climate change.
A new project Klein's team is undertaking studies the interdisciplinary affects of climate change on the plateau. Climate change is not only causing warming, but also increasing weather events like snow disasters on the Tibetan Plateau. Many of these storms come during the summer months and prevent animals from reaching the vegetation so that they starve. Snowstorms are not new, but now reports are showing that herders are starving due to these storms, which is unusual. The new project will study why pastoralists are becoming more vulnerable to disasters.
Both speakers stressed that China needs to continue to expand scientific research on climate change impacts on the Tibetan Plateau to develop better policies and investments to bolster the capacity of the communities and environment to adapt to temperature rise and melting glaciers. If the new policies are successful in protecting fragile communities and ecosystems, they could be a model for Latin America and other areas suffering similar threats from temperature rise.
Climate Change, Water, and the Himalayas (in San Francisco)
By Linden Ellis