Q. 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?

• Creating the artificial rains in some regions
• Reducing the frequency and intensity of tropical cyclones
• Reducing the adverse effects of solar wind on the Earth
• Reducing the global warming

Answer: (d) Reducing the global warming

Notes:

• Cirrus clouds, which are at a height of 10 km above the Earth’s surface.
• Cirrus clouds also trap the heat, thinning them could cool down the Earth system. 
• Thinning of cirrus clouds could be achieved by injecting ice nuclei (such as dust) into regions where cirrus clouds form, making the ice crystals bigger and reducing the cirrus optical depth.
• Thinning of the clouds could allow more heat to escape into space, thereby cooling the planet.
• The stratospheric aerosol injection could limit rising temperatures that are causing climate change.