This week’s post will cover the effects of global climate change on the glaciers of Tibet and how this will effect the populations living downstream.
Tibet is also called the ‘Third pole’ as it contains more than 46,000 glaciers, the source of the major rivers in Asia. In recent years, Tibet has seen a continuous rise in temperatures at the rate of 0.3 degree Celsius per decade, which is twice the global average temperature rise. The Tibetan Plateau is often called the barometer of Asia because its vast highlands warm faster than the oceans, which then raises the temperatures and creates an area of low pressure. This pressure gradient draws in heavy amount of moist air from the Indian Ocean and spreading it out through different regions, making it the driver of Asian monsoon.
- (Source: David Breashears) Comparing the glaciers from 1921 to today’s.
A simple visual comparison of the pictures that filmmaker and mountaineer David Breasher took of Rongbuk in 2008 with the pictures that George Mallory took of Rongbuk during his expeditions in 1921 brings to light the significant loss of ice mass in this area. The magnitude of glacier melting can be seen at the Rongbuk glacier on the northern slope of Mount Everest.
Global climate change has sped up the rate of glacial melt.
According to the Chinese Academy of Science, glaciers on the Tibetan Plateau are melting at a rate of 7% annually and if the current rate continues, two-thirds of the glaciers on the plateau will be gone by 2050.
The International Center for Integrated Mountain Development (ICIMOD), an organization that conducts research on the environment in the Hindu-Kush part of the Himalayas has revealed alarming details on the ecology. According to ICIMOD’s findings, the current trend of melting suggests that the Ganges, Indus, Brahmaputra and other rivers across the Northern India plains would most likely become seasonal rivers in the near future instead of remaining perennial. My previous post on the effects of freshwater deprivation to local communities further explored the impacts.
The formation of glacial lakes as a result of the rapid melting of glaciers on the higher reaches of the mountain ranges continues to pose a serious threat to livelihood downstream. ICIMOD has identified some 8,790 glacial lakes in parts of the Hindu-Kush Himalayas out of which, it has confirmed 204 glacial lakes as ‘likely to burst’. The sudden discharge of a large volume of water with debris would lead to massive floods known as the glacial lake outburst floods.
Around 15 Glacial Lake Outburst Floods have been recorded in the Tibet Autonomous Region alone between 1930 and 2002. They have claimed many lives and properties.
The most infamous floods in Pakistan last year that left 13.8 million people dead and 1,600 dead is directly related to the strong supercharged monsoon jetstreams that form over Tibet. Jean-Pascal van Ypersele, vice president of the Intergovernmental Panel on Climate Change (IPCC), claimed that these floods are results of the rapid global climate change, which has made the most drastic signs of changes on the glaciers of Tibet.
When glacier melts, it destabilizes the entire surrounding land, posing the threat of large landslides. These landslides sometimes block the river-ways forming unstable lakes. Such lakes always carry the danger of breaking its temporary barriers and causing flash floods downstream. For example, on April 9, 2000, a large landslide Eastern Tibet formed a landslide dam on a tributary of the Brahmaputra River. On June 10, 2000, the dam breached resulting in flash floods which caused the death of 30 peoples and the disappearance of more than 100 peoples. This flash flood in five downstream districts of Eastern India left 50,000 peoples homeless. The total economic loss was estimated at more than 22.9 million USD.
Permafrost covers a large percentage of the Tibetan Plateau. About one-third of the world’s soil carbon is stored in these permafrost regions. With its degradation, due to drastic rise in temperatures, a huge amount of carbon continues to be released into the atmosphere, contributing to global climate change.
A large part of the headwaters of the Yellow River, which supports a large portion of the Chinese population is underlain by permafrost. The melting of the permafrost along with other factors have led to the quick dry-up of the river which often has failed to reach the sea. In 1998 the Yellow River failed to reach the sea for 260 days. Experts have estimated that cities near Beijing and Tianjin could run out of water in the coming five to seven years. In order to fix the huge water shortage problems in its northern plains, China is currently undertaking large-scale diversion initiative to drain water from the Yangtze in the South-to-North Water Diversion Project.
According to Qinghai Province’s Surveying and Mapping Bureau, 5.3% of the glaciers in the headwaters of the Yangtze River has disappeared inside the last three decades. The severe Yangtze drought in 2011 that lasted for 6 months, which was considered to be the worst in 50 years.