Longer Pollen Season
Human-caused climate change has both worsened and lengthened pollen seasons across the U.S. and Canada, a new study reports.
Climate change has two broad effects, according to the study. First, it shifts pollen seasons earlier and lengthens their duration. Second, it increases the pollen concentrations in the air so pollen seasons are, on average, worse. The new research shows that pollen seasons start 20 days earlier, are 10 days longer and feature 21% more pollen than they did in 1990.