Earth is being cooled by pollutants, say researchers

May 7, 2013
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Earth is being cooled by pollutants, say researchers

We've heard quite a bit on the climate-change effects of pollution, but much of it has centered on increased global temperatures, resulting in reduced ice caps and particularly volatile storms that have ravaged many places around the world in the last decade. Now a new study has shown that pollutants can also have a cooling effect on our planet via their effects on clouds.

Clouds can have both a warming and a cooling effect on our planet, depending on their formation. Condensed water droplets are the substance of clouds, with the size of the particles upon which they are suspended being directly related to the brightness of clouds as determined from above. Obviously, the brighter a cloud, the more sunlight it reflects away from our blue marble, something that has been widely known.

In this study, the effects of pollution on clouds was looked at, in particular the effects of organic compounds released by pollutants, which make their way upwards and serve as particles. Because of their nature, the pollutant particles cause larger droplets to form, and the result is brighter clouds, which in turn reflect more sunlight. Says the researchers, though, the effects aren't likely powerful enough to combat increasing global temperatures.

Said the project's author Gordon McFiggans: "More cloud droplets lead to brighter cloud when viewed from above, reflecting more incoming sunlight. We did some calculations of the effects on climate and found that the cooling effect on global climate of the increase in cloud seed effectiveness is at least as great as the previously found entire uncertainty in the effect of pollution on clouds."

[via Science World Report]


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