The Himalayas, with their steep topography and copious water resources, provide South Asia with long-term, low-carbon hydropower. The mountain range, however, is located in one of the globe’s most seismically active areas. Earlier this month, a group of 60 leading Indian scientists and environmentalists addressed an open letter to Prime Minister Narendra Modi, requesting that he intervene to prevent “any further hydropower projects that are located in the Himalayas as well as on the Ganga, whether under construction, new, or proposed.”
The letter cites the sixth assessment report of the Intergovernmental Panel on Climate Change, which claims that warming has impacted the Himalayas. In high mountain Asia, the research cautions that “increasing precipitation and temperature can enhance the occurrence of the glacial lake outburst floods as well as landslides over the moraine-dammed lakes.” Moraine is made up of rocks and dirt that have been left behind by the moving glaciers.
As per the International Energy Agency (IEA), which is an intergovernmental organization, hydropower, the globe’s largest supply of renewable electric power with 1,308 gigawatts of existing capacity in 2019, will play a critical role in decarbonizing power networks.
The Himalayas, which stretch 2,400 kilometers and contain the world’s highest peaks, Mount Everest in Nepal as well as K2 in Pakistan, are high on the list of worldwide hotspots for creating hydropower, even though only 20% of the projected 500-gigawatt capacity has been exploited so far.
However, despite known threats from quakes, landslides, and the glacial lake outburst floods, the situation is fast changing as hydropower projects proliferate along the Himalayan arc, which spans Bhutan, China, India, Nepal, and Pakistan.
The move by the Ministry of Environment, Forest and Climate Change in India to authorize the restart of seven controversial hydroelectric projects in the Himalayan state of Uttarakhand was the immediate impetus for the petition to Modi.
Floods and landslides badly destroyed three of these projects: Phata Byung (76 megawatts), Tapovan-Vishnugad (520 megawatts), and Singoli Bhatwari (99 megawatts) in 2013 and February 2021, respectively. Several other hydropower programs in the Himalayas were also harmed. A glacial avalanche in Chamoli district’s Rishi Ganga and Dhauli Ganga basins triggered flash floods in February, killing 250 people and severely damaging land as well as infrastructure, such as the Tapovan-Vishnugad project.
C. P. Rajendran, a paleo-seismic expert and adjunct professor at the Bangalore-based National Institute of Advanced Studies, says: “The Himalayas are naturally unstable because of their vast height. These calamities serve as early warning signs that hydropower projects, infrastructure construction, and tourism activities are causing the mountains to become increasingly unstable.” Furthermore, as a result of climate change, Rajendran believes that rockfalls in the Himalayas may become more common. “Permafrost in the mountains keeps rocks together and helps maintain steep slopes, but warming in recent decades may have harmed its function as a slope stabilizer.”