The Himalayas need special policy attention, given their strategic importance and unique vulnerabilities.
The fifth assessment report of the Intergovernmental Panel on Climate Change (IPCC) predicted increased global warming, with a 1.5-2.0 degree rise in surface temperature by the end of the 21st century. This will not only make coastal regions vulnerable to sea-level rise but also make the sensitive Himalayan ecosystem more vulnerable. The increase in temperature will have a direct bearing on Himalayan glaciers, the source of several perennial rivers. It is also believed that the frequency and intensity of extreme weather and climate events will increase in a warm world.
The IPCC report also predicts the increased frequency of extreme weather events. Although extreme weather and/ or climate events have been reported in the geological record of our planet, the frequency and intensity of such events increase in a warm world. Such events have been reported on centennial to millennial time scales in the past geological record, called Dansgaard-Oeschger cycles and Heinrich events. The frequency of such extreme events has increased over the past century or so.
Last June’s Kedarnath disaster was one of the worst in the past century and led to the loss of many human lives and caused damage to property in the Mandakini (Kedarnath) valley. The loss of life and property was also reported in the Alaknanda, Gangotri and Yamunotri valleys, although on a relatively smaller scale. Several fauna and flora also suffered irreparable damage. The entire state of Uttarakhand witnessed the fury of nature, with heavy precipitation triggering widespread landslides, flash floods, destruction of roads and buildings and felling of trees. The damage was unprecedented. This meteorological event took the entire state and the country by surprise.
The Kedarnath event was a swift and shortlived meteorological event that occurred in a few minutes. Three factors contributed to the Kedarnath disaster — the bursting of Chorabari lake due to an avalanche of snow, unprecedented rains in the valley, and the melting of surface (about 1.5m) snow and glacial debris. These triggered flash floods that washed away everything along their path. A heavy boulder and the excellent construction of the Kedarnath temple saved it from the flash floods to a great extent. Approximately 330 mm rainfall in the Kedarnath valley in 24 hours during June 16-17, 2013 was reported by the observatory of the Wadia Institute of Himalayan Geology, Dehradun. The Mandakini and Saraswati rivers changed their courses and now confluence on the eastern side of the upper Kedarnath valley.
Earthquakes, glacial debris and glacial lake outburst …continued »