Thursday, November 12, 2009
India's Mystery Glacier Growth
Scientists question a government report saying the Himalayan ice cover isn't shrinking
The great glaciers of the Himalaya may not be melting as fast as thought, and in fact some may even be growing, according to a controversial report for India’s Ministry of Environment and Forests that has been greeted with disbelief by environmentalists.
The 60-page report released this week, "Himalayan Glaciers, A State-of-Art Review of Glacial Studies, Glacial Retreat and Climate Change," has set off a furor in India.
The condition of the glaciers is of paramount concern to South Asia, which depends on them as by far the region’s single biggest source of water. They fill the Ganges as well as the Brahmaputra in Bangladesh, the Mekong, which flows through Southeast Asia, the Irrawaddy in Burma, the Indus in Pakistan and the Yellow and Yangtze Rivers of China.
In its own report on India, "Global Climate Change: An Introduction," written by Sudip Mitra, the UN panel on climate change said that in the last 100 years the mean annual surface air temperature of the earth has increased by 0.4-0.6C and that it could rise another 3 to 5C by the end of the 21st century, with North India likely to become the warmest part of the country.
The Himalaya report, prepared by the GB Pant Institute of Himalayan Environment and Development, carried the cautionary statement that its conclusions "are not necessarily endorsed by the Ministry of Environment and Forests, Government of India. This series is meant to serve as a basis for informed debate and discussion on critical issues related to the environment." Nonetheless, it assumes additional significance because of the United Nations Climate Change Conference to be held in Copenhagen from Dec. 7 through Dec. 18 and appears certain to be cited by those who claim climate change is a fraud. The Copenhagen conference is the most significant climate change panel since the Kyoto Conference of Parties in 1997, which produced the Kyoto Protocol in which 38 developed countries agreed to specific targets for cutting their emissions of greenhouse gases, although the United States, the world’s largest emitter of greenhouse gases, never ratified the treaty. It became international law in 2005.
India has so far strongly opposed any binding emission targets for developing countries and, in recent negotiations in Bangkok to come up with a framework for the Copenhagen conclave, led the opposition to an Australian proposal backed by the United States and the European Union to establish a single legal instrument to reduce emissions worldwide.
The Himalaya report quotes data going back 150 years on India’s glaciers, the most extensive in the world outside of the polar ice caps. Fears of glacial retreat almost a century ago led to efforts to monitor the glaciers, according to the report, with 20-odd glaciers from Jammu and Kashmir west to Sikkim under observation by the Geological Survey of India. The studies, according to the report, show that "All the glaciers under observation during the last three decades of 20th century have shown cumulative negative mass balance." Degeneration of the glacier mass has been the highest in Jammu & Kashmir, relatively lower in Himachal Pradesh, even lower in Uttarakhand and the lowest in Sikkim."
The region’s glaciers, "although shrinking in volume and constantly showing a retreating front, have not in any way exhibited, especially in recent years, an abnormal annual retreat, of the order that some glaciers in Alaska and Greenland are reported to have done."
However, the Web site Science Daily reported in 2007 that "satellite-imagery derived glacier surface topographies obtained at intervals of a few years were adjusted and compared. Calculations indicated that 915 square kilometers of Himalayan glaciers of the test region…thinned by an annual average of 0.85 m between 1999 and 2004." Satellite data from the Indian Space Applications Center in Ahmedabad, indicates that from 1962 to 2004, more than 1,000 Himalayan glaciers have retreated by around 16 percent. According to the Chinese Academy of Sciences, China's glaciers have shrunk by 5 percent since 1950s.
Nonetheless, the report says, the Siachen glacier advanced by about 700 meters between 1862 and 1909, retreated rapidly by about 400 meters between 1929 and 1958, and has shown "hardly any retreat during the last 50 years, the report said. The Gangotri glacier, which had been retreating rapidly along the front at about 20 meters per year until 2000, "has has since slowed down considerably, and between September 2007 and June 2009 is practically at a standstill. The same is true of the Bhagirathkharak and Zemu glaciers."
Thus, the report said, "It is premature to make a statement that glaciers in the Himalayas are retreating abnormally because of the global warming. A glacier is affected by a range of physical features and a complex interplay of climatic factors. It is therefore unlikely that the snout [the leading edge of a glacier] movement of any glacier can be claimed to be a result of periodic climate variation until many centuries of observations become available. While glacier movements are primarily due to climate and snowfall, snout movements appear to be peculiar to each particular glacier."