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Achoo! Climate Change Lengthening Pollen Season in U.S., Study Shows

New research suggests that climate change is responsible for longer pollen seasons in the United States and more pollen in the air, as well.

This article, featuring a quote from Kristi Ebi (Center for Health and the Global Environment) was originally published in The New York Times.

close up image of a bee on a flower
Climate change could account for about half of the trend of a longer pollen season, a new study suggests. Credit…iStock/Getty


Among the many disasters climate change is wreaking around the world, scientists have now identified a more personal one: It’s making allergy season worse.

That is the message of a new study in the journal Proceedings of the National Academy of Sciences published on Monday. The researchers found a strong link between planetary warming and pollen seasons that will make many of us dread spring just a little bit more.

According to the new paper, the combination of warming air and higher levels of carbon dioxide in the atmosphere has caused North American pollen seasons since 1990 to start some 20 days earlier, on average, and to have 21 percent more pollen.

Scientists have suggested for some time that the season is getting longer and more awful, and the new research provides greater detail and estimates of just how much a warming planet is responsible for the greater misery. They concluded that climate change caused about half of the trend in the pollen season, and 8 percent of the higher pollen count. What’s more, the trend of higher pollen counts, the researchers said, is accelerating.

The most pronounced effects were seen in Texas, the Midwest and the Southeast, said William Anderegg, an assistant professor of biology at the University of Utah and the lead author of the new study. The effects were less obvious in the northern United States, including New England and the Great Lakes states. The greatest pollen increases came from trees, as opposed to grasses and weeds, he said.

The researchers employed the techniques of attribution science, which is commonly used to state the degree to which extreme weather events like heat waveswildfires or the amount of rain a hurricane brings are worse than they would have been in a world without climate change.

Applying this branch of science to pollen was a novel and welcome idea, said Kristie Ebi, a professor in the Center for Health and the Global Environment at the University of Washington who was not involved in the study. “It’s a great piece of work,” she said. “There has been very little research on the application of detection and attribution analysis to the health risks of a changing climate.”

Read more at The New York Times.