Soot Pollution Accelerating Glacial Melting on Tibetan Plateau

Increased levels of black soot from air pollution sources across Asia have accelerated the rate of glacial melting on the Tibetan Plateau, exacerbating the effects of global warming in what is home to the planet’s largest non-polar ice masses, researchers say. Temperatures in the region have increased 0.3 Celsius (.5 F) in the last 30 years — twice the global average rate. After studying five glacial ice cores collected across the Tibetan Plateau, NASA and Chinese scientists said a significant contributing factor is increased soot deposits, which darken the snow and ice, increasing the absorption of sunlight. Black soot may be responsible for about half of the glacial melt, said James Hansen, director of NASA’s Goddard Institute for Space Studies and co-author of the study published in the Proceedings of the National Academy of Sciences. “[C]ontinued, ‘business-as-usual’ emissions of greenhouse gases and black soot will result in the loss of most Himalayan glaciers this century,” Hansen said. The glaciers provide water storage for more than a billion people across south and east Asia, sending fresh melt water down the Indus, Ganges, Brahmaputra, and other river systems. From 1950 to 1980, about 50 percent of the glaciers were in retreat, the authors say. In recent years, nearly 95 percent have been retreating.