Whiter Clouds could cause the land to become wetter

6 July 2010 | Green Technology | No Comments

We talked in an older post about “cloud whitening”, and we concluded that it is actually a real solution to stop global warming. But after some studies, researchers announced that this scheme could also change global rainfall patterns, raising concerns of water shortages on land. The clouds placed over the oceans will reduce the solar radiation absorbed by the Earth, but on the other hand, the clouds could cause the land to become wetter.

“Rain clouds, which have big droplets, tend to be grey and absorb sunlight, whereas clouds with smaller droplets tend to be white and fluffy and reflect more sunlight to space…In practice this could be done by shooting a fine spray of seawater high into the air, where the tiny salt particles would create condensation nucleii to form small cloud droplets.”, said Ken Caldeira of the Carnegie Institution’s Department of Global Ecology.

Afther some studies made using computer simulations Caldeira and his coauthors concluded that the increased precipitation over land was driven by changes in the atmosphere, similar to the monsoonal pattern that determines rainfall in Asia. “Monsoons occur when air masses over land are warmer than air masses over the ocean, and this draws in cool, moist air from over the ocean which then drops rain over the land,” says Caldeira.

“In real life, there are only certain parts of the ocean in which you could make the cloud droplets smaller…An actual deployment would be much patchier than in our study, and the result would therefore be somewhat different. But our basic result calls into question previous assumptions about the impact of this geoengineering scheme. It merits further investigation.”

Tags: changes in the atmosphere, cloud whitening, cloud whitening wetter lands, global rainfall patterns, Monsoons, Rain clouds, solar radiation absorbed, whiter clouds

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