Publication Name

Black carbon – An additional factor in accelerated melting of Himalayan glaciers?

CASE STUDY

Black carbon is a product of incomplete combustion (burning that gives off smoke) and is the main constituent of soot. The current level of understanding, which is still evolving, suggests that more than half the black carbon emitted in South Asia comes from the burning of biomass – mainly wood and mostly from cooking fires. Most of the black carbon that is deposited on the Himalayan mountains and southern parts of the Tibetan plateau comes from the South Asian plains, but black carbon can also be transported through the atmosphere over long distances and can come from as far away as Africa, the Middle East, central China and Europe. Black carbon can affect the climate in the Himalayan mountains in two ways. When deposited onto snow or ice, it darkens the surface allowing more sunlight to be absorbed and, therefore, warming the surface and increasing melting. Black carbon also absorbs sunlight when it is suspended in the atmosphere. The air heated by the atmospheric black carbon is in contact with the mountains, warming them. This is the likely explanation for the more rapid increase in temperatures at higher altitudes over the last few decades. Black carbon is likely to be responsible for a considerable part (around 30%, by some calculations) of the glacial retreat that has been observed across the HKH region. 68 Significant research needs to be done to better establish the relationship between black carbon, glacial melt and water in general.

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