Human-caused climate change is making allergy season longer and more severe. In a study led by the University of Utah School of Biological Sciences, the pollen season in North America is starting earlier and lasting longer than it did four decades ago.
The findings, which were published in the Proceedings of the National Academy of Sciences (PNAS), show that pollen season starts earlier, stays longer and has more pollen than 1990s. Climate change is responsible for nearly half of these changes, the study adds. The researchers gathered measurements between 1990 and 2018 from 60 pollen count stations across the US and Canada, recorded by the National Allergy Bureau.
“A number of smaller-scale studies—usually in greenhouse settings on small plants—had indicated strong links between temperature and pollen,” said Bill Anderegg, a biologist and climate scientist at the University of Utah and the lead author of the study, in a statement. This study reveals that connection at continental scales and explicitly links pollen trends to human-caused climate change, he elaborates.
“People who have allergies, sinusitis, asthma or any other airway inflammatory disease frequently complain that their symptoms get worse with changes in the weather, and it seems like it’s when various fronts come through and there is a big temperature change,” said Dr David Corry, professor of medicine-immunology, allergy and rheumatology at Baylor.
Global warming is causing extra weeks of itching, sneezing, and runny noses; another reason to cut emissions of greenhouse gases, biologists say. “The strong link between warmer weather and pollen seasons provides a crystal clear example of how climate change is already affecting people’s health,” said Dr William Anderegg of the University of Utah, in a statement.