Projected climate-driven changes in pollen emission season length and magnitude over the continental United States

This study uses a pollen emission model and future climate data to simulate changes in anemophilous pollen emission. Warmer end-of-century temperatures (4–6 K) are projected to shift spring emissions 10–40 days earlier and summer/fall emissions 5–15 days later, lengthening the season. Temperature and precipitation changes alter daily pollen emission maxima by –35 to 40% and increase annual total pollen emission by 16–40%. Doubling CO2 production, along with climate change, could increase end-of-century emissions up to 200%. Land cover change has a relatively small effect (<10%). These findings suggest that increased pollen and longer seasons will worsen seasonal allergies.

Yingxiao Zhang, Allison L. Steiner