The culprit is what the study referred to as “aerosol”, or common black soot from industry, transportation and agriculture in India and China. The dust settles onto the snow and reduces its albedo (reflectivity), causing it to absorb more solar energy than white snow. As snow melt increases, a cascade of changes happen to the precipitation cycle.

Because there is less snow on the plateau in the summer to reflect the sun, temperatures increase. The dry hot air is the driving force behind the region’s famous monsoons, so the result is intensified rain in southern and northern China and a drier central China. The intensified cycle also takes more soot and distributes it higher and further than before, starting the process all over again.

The study’s authors from Pacific Northwest National Laboratory (PNNL), the University of Michigan, and the National Oceanic and Atmospheric Administration (NOAA) conclude that the dirty snow will have more impact on ecology that CO2’s effect on global warming. It’s a double whammy caused by fossil fuel use that has a specific and immediate effect on those who depend on the extraordinary Tibetan Plateau.

+ Atmospheric Chemistry and Physics

Via Physorg.com

Photographs from Wiki Commons

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