Question

UPSC Prelims 2019 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?

1. Creating the artificial rains in some regions
2. Reducing the frequency and intensity of tropical cyclones
3. Reducing the adverse effects of solar wind on the Earth
4. Reducing the global warming

Answer (Detailed Solution Below)

Option 4: Reducing the global warming

Detailed Solution

Explanation:

Stratospheric Aerosol Injection (SAI) is a geoengineering technique to inject sulphate aerosol into the stratosphere to control global warming. Global warming can be controlled by either controlling carbon emissions or by controlling solar radiation from reaching the earth’s surface.
SAI technique proposed spraying large quantities of aerosols (Sulphate particles) into the Stratosphere (upper layer of the Atmosphere) to act as a reflective barrier against sunlight. These reflective particles block and reflect the sun’s rays back to space, which reduces heat absorbed by the earth. Thus, it limits rising temperatures that are causing global warming and climate change.

Therefore, option (4) is the correct answer.

Knowledge Box

In 2021, the ‘Intergovernmental Panel on Climate Change’ (IPCC) proposed Cirrus Cloud Thinning (CCT) technique to reduce global warming. CCT works by reducing the amounts of cirrus clouds by injecting ice nucleating substances into the upper troposphere.
- Cirrus clouds are high-cold ice that, like other clouds, both reflect sunlight and absorb warming infrared radiation that led to global warming. Therefore, thinning or removing these clouds would reduce their heat trapping capacity, resulting in a cooling effect on Earth's climate. This could be a potential tool to reduce anthropogenic global warming.
SAI technique replicates the natural process which happens during volcanic eruptions. Volcano while erupting releases a large amount of SO2 into the Stratosphere, which inhibits the incoming solar radiation from reaching the earth's surface and results in cooling down the planet.

Subject: Environment | Climate Change

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