Record Spike in Aerosol in Hindu Kush Region: Study by ISRO
Atmospheric aerosols consist of solid/aqueous particles suspended in the lower atmosphere and are typically of sizes in a range of 0.001–10 micrometers.
Recently, a study by ISRO highlights elevated levels of aerosols in The Hindu Kush-Himalaya-Tibetan Plateau region causing concerns of increased detrimental impact on Global climate.
Aerosols source:
♦ Natural: volcanic eruptions, dimethyl sulfide emissions from phytoplankton, etc.
♦ Anthropogenic: fossil-fuel burning, deforestation fires, etc.
The study used data sources and simulations to evaluate aerosol properties and Aerosol Radiative Forcing and Efficiency (ARFE), over Hindu Kush Region.
- ARFE shows the effect of anthropogenic aerosols on the total amount of radiation that the earth and its atmosphere absorb, convert into heat, and re-emit.
Findings
- ARFE is 2-4 times higher than over other sites in South and East Asia.
- Aerosols alone could account for >50 % of the total warming over this region.
Aerosol-induced warming leads to:
- increasing air temperature, observed accelerated retreat of glaciers.
- changes in the hydrological cycle and precipitation patterns over the region.
Hindu Kush-Himalayan region spans an area of approximately. 4.3 million square km in Afghanistan, Bangladesh, Bhutan, China, India, Myanmar, Nepal, and Pakistan.
A 2019 report by the International Centre for Integrated Mountain Development (ICIMOD) found that the Hindu Kush Himalayas are warming faster than the global average, and that the consequences of it in the region were severe.
That ICIMOD report highlighted that 1.5 degrees Celsius is “too hot” for the Hindu Kush Himalayas.
David Molden, former director-general of ICIMOD, said that global warming of 1.5 degrees Celsius will actually mean in a 2 degrees Celsius temperature increase in the mountains.
“This would affect half the glaciers in the HKH region, destabilising Asia’s rivers and endangering the lives and livelihoods of billions of people.”
The PRL study also warned of similar consequences. Researchers have also observed ice loss along the entire 2000-km transect of the Himalayas, which, they said, could be the result of direct heating of the atmosphere by aerosols.