Black carbon mixes with other anthropogenic aerosols and dust to create thick winter haze that hugs the southern foothills of the Himalayas. This haze warms the atmosphere and may contribute to rising regional temperatures, melting glaciers, and shifts in the timing, duration, and intensity of the South Asian summer monsoon. Photo provided by NASA.
The Hindu Kush-Himalayan-Tibetan region—the “Third Pole”—has seen a temperature increase of 1.2°C over the last 120 years, twice the global average.
As a result of this enhanced warming, glacial retreat is accelerating across much of the region, with Himalayan glaciers retreating faster than the world average. In addition, many parts of the region are experiencing a significant decrease in monsoon precipitation and strength since the early 1900s. This weakening monsoon means less water, which matters a lot in a region where the summer monsoon is the biggest source of freshwater for drinking and food production.
While CO2 is the primary culprit, recent studies suggest that black carbon (BC) may play as large a role in warming the HKHT region. Increasing amounts of soot in atmospheric brown clouds have been shown to cause atmospheric solar heating, surface dimming, and BC deposition to the HKHT glaciers and snow pack.
Because of the potential threat of BC to this region, CATF, along with partner groups:
- Is examining the current state of understanding of the role of BC in the Himalayas and Tibetan Plateau, advocating for a snow measurement campaign in high elevation regions of China.
- With support from CATF, Delhi-based Greentech Solutions and the University of Illinois conducted a study of the BC emissions from different types of brick kilns in India and Vietnam. Brick kilns had previously been identified as producing large amounts of BC but data was very limited. The results of this study will be available in early 2012.
