Geoengineering, a term that refers to various theoretical ideas for altering the Earth’s energy balance to combat climate change. An international team of atmospheric scientists investigates for the first time the possibility of using a “cocktail” of geoengineering tools to reduce changes in both temperature and precipitation caused by atmospheric greenhouse gases.
Solar geoengineering aims to cool the planet by deflecting some of the Sun’s incoming rays. Includes dispersion of light-scattering particles in the upper atmosphere, which would mimic the cooling effect of major volcanic eruptions. However, climate-modeling studies have shown that the scattering of sunlight reduces the warming caused by greenhouse gases in the atmosphere. It would tend to reduce rainfall and other types of precipitation less than would be optimal.
Another approach involves thinning of high cirrus clouds, which involved in regulating the amount of heat that escapes from the planet to outer space. It reduces warming, but would not correct the increase in precipitation caused by global warming.
Scientist Ken Caldeira from Carnegie Science Center, said, one method reduces rain too much. Another method reduces rain too little. For that theoretical cocktail shaker gets deployed.
Researchers used models to simulate what happens if sunlight scattered particles at the same time as the cirrus clouds thinned. Their simulations showed that both methods deployed in concert. It would decrease warming to pre-industrial levels, as desired, and on a global level rainfall would also stay at pre-industrial levels. But, the global average climate largely restored, substantial differences remained locally, with some areas getting much wetter and other areas getting much drier.
Caldeira said, the same amount of rain fell around the globe in our models, but it fell in different places. Which creates a big mismatch between what our economic infrastructure expects and what it will get.
More information: [Geophysical research letters]