Glaciers of the Himalayas Climate Change, Black Carbon, and Regional Resilience

Melting glaciers and the loss of seasonal snow pose significant risks to the stability of water resources in South Asia. The 55,000 glaciers in the Himalaya, Karakoram, and Hindu Kush (HKHK) mountain ranges store more freshwater than any region outside of the North and South Poles. Their ice reserves feed into three major river basins in South Asia—the Indus, Ganges, and Brahmaputra—that are home to 750 million people. One major regional driver of the accelerating glacier melt is climate change, which is altering the patterns of temperature and precipitation. A second driver may be deposits of anthropogenic black carbon (BC), which increase the glaciers’ absorption of solar radiation and raise air temperatures. BC is generated by human activity both inside and outside of South Asia, and policy actions taken by the South Asian countries themselves may meaningfully reduce it. Glaciers of the Himalayas: Climate Change, Black Carbon, and Regional Resilience investigates the extent to which the BC reduction policies of South Asian countries may affect glacier formation and melt within the context of a changing global climate. It assesses the relative impact of each source of black carbon on snow and glacier dynamics. The authors simulate how BC emissions interact with projected climate scenarios. They also estimate the extent to which these glacial processes affect water resources in downstream areas of these river basins and present scenarios until 2040. Their policy recommendations include the following: Full implementation of current BC emissions policies can significantly reduce BC deposition in the region; additional reductions can be realized by enacting and implementing new policies that are economically and technically feasible. Improving the efficiency of brick kilns could be key to managing BC, and modest up-front investments could pay off quickly. Cleaner cookstoves and cleaner fuels can help to reduce BC and improve local air quality. Improving institutions for basin-based water management and using price signals are essential elements of more efficient water management. Careful management of hydropower and storage resources will require developers to factor in changing water flows and consider planning for large storage projects to stabilize water availability. Regional cooperation and the exchange of information can be an effective transboundary solution, helping countries to manage glaciers and related natural assets collaboratively. New policies are needed to reverse trends like the melting of glaciers. Success will require an active, agile cooperation between researchers and policy makers. To support an open dialogue, the model developed and used in this book is an open-source, state-of-the-art model that is available for others to use and improve on.