New research out of UC San Diego and the University of Texas shows certain types of air pollution can have significant climate-related impacts depending on where that pollution is emitted.
The study, published in the journal Science Advances, is the first to examine the link between aerosol pollution and climate effects.
Aerosols are tiny particles of material like soot from wildfires, or droplets of water from smokestacks or tailpipes. Aerosol emissions can also affect economic and agricultural productivity depending on where they are released.
Researchers have long known that the particle pollution impacts health. But, the new findings show aerosols also increase the climate effects of greenhouse gas emissions.
“It is not surprising to see that they have a big impact on societal damages compared to carbon dioxide,” said co-author Geeta Persad, a researcher at the University of Texas in Austin. “What was surprising to me was to see how different those societal damages are, depending on who emits the aerosol.”
And where those emissions happen. The impact is also tied to geography.
“The total number of infant deaths that we get from a given amount of aerosol emissions, say coming from India, is about 100 times more than emitting the same amount of aerosol from the U.S.,” Persad said.
The pollution is often released at the same time as carbon dioxide, which carries a cumulative impact on the climate. The more carbon released into the atmosphere, the warmer the planet’s climate becomes.
Aerosols act differently. Their effect tends to happen close to where they were emitted making it harder to measure widespread climate impacts.
“Aerosols that are co-emitted, with carbon dioxide and greenhouse gasses have all sorts of additional negative effects globally and so we should probably be keeping track of that as well,” said co-author Jennifer Burney, a researcher at UC San Diego.
But scientists did measure regional impacts in eight key regions: Brazil, China, East Africa, Western Europe, India, Indonesia, South Africa, and the United States.
They found that aerosol pollution could boost the regional climate impact of greenhouse gas emissions by more than 60%.
Some aerosols have reflective properties prompting researchers to ask if there were any climate benefits. The study found the emissions were always bad for the region where the pollution was created and the overall health of the planet.
Burney suggested shifting the public policy focus from just managing the pollution to managing the pollution and climate.
“The big fight in the U.S. is can the EPA think of air pollution, climate change and greenhouse gasses holistically,” Burney said. "Are we going to let the EPA do that, this has been the policy fight.”
