Fears that switching to cleaner sources of energy could speed up global warming by reducing pollution are unfounded, new research suggests.
Last year scientists said aerosols pollution the atmosphere might paradoxically be slowing down global warming by reflecting the sun's light and heat back into space. A study found cleaning them up might add 1C to temperatures, making it far less likely the world can stay beneath the targets agreed to in Paris in 2015.
But the team behind new research published this week in Nature say they've resolved the paradox.
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"The fear that reducing air pollution could lead to a spike in global warming has been a lingering concern for climate scientists," said Dr Nicolas Bellouin of the United Nations' Intergovernmental Panel on Climate Change, who contributed to the new research.
"What if our efforts to clean up the air actually meant we make global warming worse?"
Thankfully that doesn't appear to be the case.
"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 lead author Velle Toll of 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.
"This reduces a big area of uncertainty for future forecasts of the climate. 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."
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Dr Bellouin said even if clearing pollution does result in a small increase in temperatures, the benefits outweigh the costs.
"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.
"In any case, a small temperature rise resulting from cutting pollution is a price very much worth paying to prevent greater, long-term harm caused by greenhouse gases."
July was the world's hottest month on record. On Saturday Climate Change Minister James Shaw revealed the Government's strategy for doing its bit to curb emissions and restrict the damage.