‘Global Warming won’t escalate with reduction in air pollution’: Study

LONDON: A study conducted by researchers at the University of Reading in UK in association with University of Tartu in Estonia has discovered that, contrary to popular belief, global warming won’t escalate with the reduction in air pollution. 

Scientists have long worried that air pollution, while having a devastating impact on human health, may paradoxically have been acting as a ‘brake’ on the heating of the atmosphere, said researchers at the University of Reading in the UK.

According to scientists, the assumption is backed up by the fact that pollution particles help clouds to form with more water droplets, meaning they reflect more of the Sun’s energy back into space. This, however, hasn’t been backed up by research till now and the extent to which pollution inadvertently helps to cool the planet has not been clear.

However, new research published in the journal Nature indicates that pollution affects different clouds in different ways. While some clouds get thicker, others become thinner, meaning pollution is less likely to disperse more than half of greenhouse gas warming. The findings offer greater hope that current plans to curb global warming by moving to cleaner sources of energy may still work without leading to an unexpected extra source of heating.

“Until now, it was assumed that thicker clouds form when water droplets condense around the particles in polluted air, delaying rainfall, and allowing clouds to reflect more sunlight back into space,” said Velle Toll, lead author of the study, now at the University of Tartu in Estonia.

“To test this, we studied satellite data from clouds near sources of pollution. In fact, there was little change in average water content across all the polluted clouds we found, showing that pollution makes little difference overall to many types of clouds. Some clouds got thicker, but other areas thinned out,” Toll said.

“Our study provides more evidence that cutting emissions of greenhouse gases and air pollution is a win-win situation for the health of people’s lungs and for preventing the worst impacts of climate change,” said Toll.

The research is based upon observations made by the team of scientist who surveyed the world for clouds formed over well known for being areas of pollution using near-infrared satellite images. Clouds affected by pollution appear ‘brighter’ in these images, researchers said.

They were able to identify hundreds of such polluted clouds around the world, produced by tiny pollution particles from sources like volcanoes, cities, ships, factories and wildfires.

“The fear that reducing air pollution could lead to a spike in global warming has been a lingering concern for climate scientists,” said Nicolas Bellouin, study co-author from the University of Reading. The study assures that polluted air has a limited ability to prevent the atmosphere from heating up, in addition to being bad for people’s health.

“There is now one less excuse for us not to cut emissions of both air pollution and greenhouse gases, or we will continue to see temperature rises that put people and the natural world in danger,” Bellouin said.