Correct Answer: (d) Reducing the global warming
Solution:For reducing the global warming Geo-engineering solutions have often been suggested by the scientists. Injection of sulphate aerosols, very fine solid particles, into the stratosphere is one of the most widely discussed ideas. Sulphate aerosol particles are very good reflectors of sunlight, and it has been shown, through various climate models, that even if 1% of current incident solar radiation is reflected back in space, a very significant amount of temperature rise on earth can be offset. Another way of instantly cooling the planet is the use of cirrus cloud thinning technique. These clouds are composed mainly of ice crystals and they have greenhouse property. They let the solar radiation pass through and reach the surface, but trap the higher wavelength infrared radiation emitted from the earth, thereby contributing to the heating. If these clouds are reduced by some engineering interventions, it would allow the IR radiation from the earth, too, to pass through to space, thus allowing some of the heat to dissipate and hence cool the planet.
