New study links air pollution to hurricanes

(CNN) – As the United States and Europe worked for decades to reduce air pollution for the benefit of public health and the planet, scientists discovered an unexpected – and worrying – effect: an increase in tropical storms in some regions.

A New studio Published Wednesday in the academic journal Science Advances, the last four decades saw a 50% decrease in aerosols in North America and Europe, a small particle of air pollution, and a 33% increase in the number of hurricanes. North Atlantic.

On the other hand, the study found that a 40% increase in aerosol pollution in China and India over the same period led to a 14% drop in the number of hurricanes recorded in the western North Pacific. Air pollution has increased significantly during this period due to economic and industrial development in China and India.

“Reducing aerosol emissions is a good thing for human health, but on the other hand, we have found that reducing aerosol emissions has some negative effects, which is what hurricane activity is all about,” senior author Hiro Murakami told CNN. Research and Scientist at the Geophysical Fluid Dynamics Laboratory of the National Oceanic and Atmospheric Administration (NOAA, its abbreviation in English).

Aerosols are not like greenhouse gases. Unlike carbon dioxide or methane, which are small particles of pollutants floating in the air and absorbing sunlight and causing warming, aerosols Reflecting sunlight In space having a cooling effect. Natural aerosols exist, but until the early mid-20th century most of the pollution came from sources such as industrial fumes and automobile emissions.

After decades of clean air legislation in the United States and similar measures in Europe as aerosol pollution decreased, the oceans absorbed more sunlight and raised sea surface temperatures. Murakami found that this caused more storms.

Murakami warns that his results do not mean stopping air pollution control. Reducing aerosol emissions is like stopping smoking, he said. If a person stops smoking, his health will improve and he will prevent cancer. But in some cases, side effects such as weight gain and feeling stressed can also be omitted.

“The aerosol collapse is really similar,” he said. “Lowering the aerosol will lead to better health, but on the other hand, it increases the risk of hurricanes. This is where the good things meet the bad. It’s a kind of exchange.”

Jim Kozin, a hurricane scientist with the Climate Service who reviewed the research, said the study was important to differentiate how storms respond to air pollution and greenhouse gases.

“Tropical cyclones are beautiful random beasts that respond to the randomness of the atmosphere at any moment,” Kozin told CNN. “But of course this constant sea warming is increasing in the Atlantic because of the increased greenhouse gases and less particle pollution, which has a profound effect, and the changes in particle pollution particles have a more dramatic effect on hurricanes.

Other scientists who have not been involved in the study agree with what they know about the complexity of air pollution and add to the development of research on how. Climate crisis May affect the hurricane.

“This study shows very well that the impact of aerosols is not isolated in the Atlantic Ocean, but indicates a global shift in the distribution of tropical cyclones,” Gabriel Wecci, a professor of climate and geology at Princeton University, told CNN. “Aerosols are one of the most uncertain components of the climate system, so I think there should be follow-up studies that explore the sensitivity of the results to many aerosol-related uncertainties.”

Tom Nutson, a senior scientist at NOAA’s Geophysical Fluid Dynamics Laboratory, who has not been involved in the study, said aerosol pollution is another important way humans have modified hurricane activity over the past 40 years.

“It’s like aerosols are creating a kind of hurricane holiday in the Atlantic, but when we reduce the production of aerosols, it’s coming back,” Natson told CNN. “We have a lot of things that we think are going on in the Atlantic, and this study is one of a number trying to tease the relative influence of these different things.”

Murakami predicts that aerosol pollution will remain stable, so greenhouse gas emissions will begin to have a greater impact on hurricanes over time, especially in their intensity.

“Climate science is very complex and it’s a job, especially for hurricane action,” Murakami said. “What we’ve recorded in the last 40 years does not apply to the future, so we can record something very different.”