It has been evident that there has been a constant elevation in the global temperatures due to the swiftly rising carbon dioxide concentrations. Several attempts have been made to tackle global warming and they are mainly focused on stabilizing & then decreasing the concentration of carbon dioxide. However, these attempts will show its effect only in the long term. In the meantime, temperatures are projected to continue to increase.
Since long, researchers have been making efforts to seek alternative approaches to control the rising temperatures in the present moment. Planetary scale geoengineering solutions have frequently been recommended. One of the notions that has been investigated for quite some time entails locating artificial reflectors—very tiny reflecting particles or giant mirrors—in outer space so as to reflect some portion of incident solar radiation on the surface of the Earth.
By stopping a portion of sun rays, it is possible to bring down the temperature on the Earth. Injection of sulfate aerosols, extremely small solid fragments, into the stratosphere is the most broadly considered notion to attain this objective. Sulfate aerosol particles are good sunlight reflectors and have been demonstrated, through diverse climate prototypes, that even if 1% of existing incident solar radiation is returned in space, an extremely considerable amount of temperature rise can be offset on Earth.
Another approach for cooling the Earth instantly is by decreasing the bulk of high-altitude clouds, created at heights of about 10 km from the surface of the Earth. These clouds, entitled cirrus, are made mostly of ice crystals. Similar to carbon dioxide in the environment, these clouds also possess greenhouse property. They allow the solar radiation to pass across and reach the surface, but entrap the higher wavelength IR released from the Earth, thus adding up to the heating. If by some engineering interventions, these clouds are condensed, it would enable the IR radiation from the planet to pass through to space, thereby letting some of the heat to disperse and consequently, cool the Earth.
Over the years, numerous studies have evaluated the feasibility and the probable effects of geoengineering solutions. Computer simulations with the use of these models have demonstrated that preferred decrease in temperatures can be attained by both these techniques.
Recently, for the first time, the team has succeeded in attaining concurrent balance by integrating the two approaches. In computer simulations, they examined the effects of sulfate aerosol inoculation in the upper stratosphere coupled with the effect of cirrus cloud thinning. By cautious calibration, the team was able to reinstate pre-industrial temperature levels as well as precipitation via these geoengineering models.