Context:
Hindu Kush-Himalaya-Tibetan Plateau region has been witnessing an alarming increase in aerosol levels, a new analysis by the ISRO’s Physical Research Laboratory.
Highlights of the Study:
- Objective – 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.
- 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.
- Impacts of Aerosol-induced warming –
- Increasing air temperature
- Formation of large amounts of reactive chlorine
- Observed accelerated retreat of glaciers
- Changes in the hydrological cycle and precipitation patterns over the region
Atmospheric aerosols:
- Atmospheric aerosols consist of solid/aqueous particles suspended in the lower atmosphere
- It can be either emitted directly into the atmosphere as a particle, like ash, or form when emitted gases undergo complex chemical reactions and condense as particles.
- Size range – 0.001–10 micrometers
- Aerosols source –
- Natural – volcanic eruptions, dimethyl sulfide emissions from phytoplankton, etc.
- Anthropogenic – fossil-fuel burning, deforestation fires, etc.
Hindu Kush-Himalayan region:
- Often referred to as the ‘Third Pole’
- Spans an area of approximately 4.3 million square km.
- 8 Countries – Afghanistan, Bangladesh, Bhutan, China, India, Myanmar, Nepal, and Pakistan.
- Source of 10 large Asian river systems – Amu Darya, Indus, Ganges, Brahmaputra, Irrawaddy, Salween (Nu), Mekong, Yangtse, Yellow River, and Tarim (Dayan).
Source: Hindustan Times
Previous Year Question
In the context of which of the following do some scientists suggest the use of cirrus cloud thinning technique and the injection of sulphate aerosol into stratosphere?
[UPSC Civil Services Exam – 2019 Prelims]
(a) Creating the artificial rains in some regions
(b) Reducing the frequency and intensity of tropical cyclones
(c) Reducing the adverse effects of solar wind on the Earth
(d) Reducing the global warming
Answer: (d)
