The Southeast is likely to be more impacted than other parts of the country, scientists said. Much of the region’s pollen comes from oak, pine, cypress and other tree species. Zhang said many of those varieties likely will become even more prolific as climate change accelerates.
Experts say the findings are in line with recent documented trends.
A study published last year in the Annals of Allergy, Asthma and Immunology found that rising seasonal temperatures are already prompting plants in Atlanta to release their pollen earlier. Examining the last three decades, the study found that pollen from oaks and eastern red cedars increased each year by roughly 5.2% and 9.9%, respectively, in the city.
“Our study found that, for almost every type of allergenic tree included in our study, pollen count increased from 1992 to 2018,” said Arie Manangan, lead author of that study and a health scientist at the Centers for Disease Control and Prevention’s National Center for Environmental Health.
The Nature study found that while rising temperatures are likely to unleash more intense pollen seasons, rising carbon dioxide (CO2) concentrations may contribute even more to the problem. Plants absorb CO2 for photosynthesis and, with more of the gas available in the atmosphere, it could spur plant fertility and lead to even more explosive pollen production. However, the authors cautioned that more research is needed to determine how large of an effect this will have.
Besides being an irritant, pollen exposure can have serious health impacts, particularly in children, said Allison Steiner, a professor of climate, space sciences and engineering at the University of Michigan and a contributing author of the Nature Communications study. Pollen can trigger asthma attacks, and high counts have been associated with decreased work productivity and lower test scores, she said.
Even those who aren’t currently suffering from a runny nose or scratchy eyes in today’s environment should pay attention, Steiner said.
“People who don’t have allergies now might think they won’t be affected,” she said. “But as (pollen) loads increase, there is the potential that more people could be sensitized over their lifetimes and it could impact an even greater fraction of the population.”