Over the past 50 years, air quality has significantly improved in many parts of the world, largely due to legislation like the U.S. Clean Air Act. These efforts targeted pollutants such as aerosols, which include sulfur dioxide and nitrogen dioxide, and have been detrimental to human health.
Unlike greenhouse gases, which contribute to global warming, aerosols actually have a cooling effect on the earth as they reflect the sun’s rays. However, if aerosols are removed from the atmosphere, the health impacts of pollution would decrease, but it might also exacerbate global warming.
Recent research has also revealed that the interaction between aerosols and greenhouse gases has implications for flooding. The presence of toxic aerosols in the atmosphere over the United States helped suppress the impacts of climate change on rainfall for decades.
Aerosols and greenhouse gases have had opposing effects on rainfall, with aerosols making things drier in most of the U.S. The decline in aerosol pollution due to the Clean Air Act led to an increase in rainfall, and could potentially worsen flooding in the future.
The findings of this research have important implications for environmental regulation, especially in regions like the Southeast of the United States. Strict regulations on industrial pollution could protect residents from diseases caused by aerosols, but it could also exacerbate extreme weather events such as hurricanes and severe flooding.
