A new U.S. government study has found that cleaner air in the United States and Europe gives birth to more hurricanes in the Atlantic.
A study by the National Oceanic and Atmospheric Administration links changes in regionalized air pollution around the globe to storm activity going both up and down. According to the study, a 50 percent reduction in particulate matter and droplets in Europe and the United States is due to a 33 percent increase in Atlantic storms over the past few decades, while in the Pacific the opposite is true with more pollution and fewer typhoons. published Wednesday in Science Advances.
NOAA Hurricane scientist Hiroyuki Murakami conducted a variety of climate computer simulations to explain changes in storm activity in different parts of the globe that cannot be explained by natural climate cycles, and found a link to aerosol pollution from industry and automotive industry. into air from which it is difficult to breathe and see.
Scientists have long known that aerosol pollution cools the air, sometimes reducing the greater impact of greenhouse gases from burning fossil fuels, and in previous studies it was mentioned as an opportunity to increase Atlantic storms, but Murakami found it a worldwide factor and more direct reference.
Hurricanes need warm water – heated by air – to fuel and harm the wind shear that changes with the wind at the top level, which can behead the tops of storms. Cleaner air in the Atlantic and dirtier in the Pacific from pollution in China and Indiamess with both, Murakami said.
In the Atlantic, the peak of aerosol pollution reached around 1980 and has been steadily declining since then. This means that the cooling that masked the warming of greenhouse gases is disappearing, so the sea surface temperature is rising even more, Murakami said. In addition, the lack of cooling aerosols helped push the jet stream – a river of air that moves weather from west to east on a roller coaster-like path – further north, reducing the shear that dampened hurricanes.
“That’s why the Atlantic has gone crazy since the mid-90s and why it was so quiet in the 70s and 80s,” said climate and hurricane scientist Jim Cosin of The Climate Service. He was not involved in the study, but said it made sense. Aerosol pollution “gave rest to many people in the 70s and 80s, but now we are all paying for it”.
There are other factors of activity of tropical cyclones from La Nina and El Niño – natural fluctuations in equatorial temperatures of the Pacific Ocean, which are changing climate around the world – are huge. Human-induced greenhouse gas-induced climate change, which will grow as aerosol pollution decreases, is another, and there are other natural long-term climate fluctuations, Murakami said.
Climate change due to greenhouse gases is expected to slightly reduce the total number of storms, but increase the number and strength the most intense hurricanesmake them wetter and increase storm floods, said Murakami, Kosin and other scientists.
While aerosol cooling is perhaps half to one-third less than greenhouse gas warming, it is about twice as effective at reducing the intensity of tropical cyclones compared to warming that increases it, said Columbia University climatologist Adam Sobel. participated in the study. study. As aerosol pollution in the Atlantic remains low and greenhouse gas emissions are rising, the impact of climate change on storms will intensify in the future and become more visible, Murakami said.
In the Pacific, aerosol pollution by Asian countries increased by 50 percent from 1980 to 2010 and is beginning to decline. The formation of tropical cyclones from 2001 to 2020 is 14 percent lower than in 1980-2000, Murakami said.
Murakami also found a correlation that was slightly different to the south. Reducing aerosol pollution in Europe and America has changed global air structures in a way that has meant a reduction in storms in the southern hemisphere around Australia.
But no matter how many hurricanes in the Atlantic were not a problem, the number of deaths from additional storms is unmatched by the seven million people a year worldwide who die from air pollutionsaid Christie Abby, a professor of public health at the University of Washington who studies health, climate and extreme weather.
“Air pollution is the main killer, so reducing emissions is crucial, no matter what happens to the number of cyclones,” said Abby, who was not involved in the study.
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