The world is getting surprisingly cooler despite the increased use of emissions and pollutants, according to top Manchester scientists.
A study released by researchers at the University of Manchester revealed that the nature of organic material inside particles which carry water droplets – the make-up of clouds – changes at in different parts of the atmosphere.
These ‘seed’ particles control the effectiveness with which sunlight is reflected back into space, depending on the amount of particles that have accumulated and become cloud droplets.
These particles can contain a large amount of organic material, with these compounds being quite volatile while existing as a vapour in warm conditions.
According to the research, published in the journal Nature Geoscience, the organic compounds – either from pollution or naturally occurring – evaporate and give off characteristic aromas.
They found that under cooler conditions where clouds form, the molecules liquefy and make larger particles – aiding the formation of cloud droplets.
Professor Gordon McFiggans from the University of Manchester’s School of Earth, Atmospheric and Environmental Science, who wrote the study, said:
“We discovered that organic compounds such as those formed from forest emissions or from vehicle exhaust, affect the number of droplets in a cloud and hence its brightness, so affecting climate.”
“We developed a model and made predictions of a substantially enhanced number of cloud droplets from an atmospherically reasonable amount of organic gases.
“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.”
Picture courtesy of Wisconsin Department of Natural Resources, with thanks.
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