Story at a glance
- New research proposes climate change is intensifying pollen season in North America.
- This can exacerbate allergies and asthma.
The adverse effects of climate change are often touted as warmer temperatures, rising sea levels and severe weather patterns and phenomenons.
One new study posits that the gradual increase in global temperatures may bring pollen season earlier than usual, as published in the journal Proceedings of the National Academies of Sciences (PNAS).
Pollen season, which typically occurs in the spring months in North America, causes respiratory and sinus issues, as well as an exacerbation of asthma, depending on the amount of pollen in the atmosphere. The report writes that pollen concentrations are often temperature-sensitive and looks at historical data spanning 1990 to 2018 to observe any connections in climate change and pollen volume in the atmosphere.
Scientists reported finding common pollen metrics, such as daily pollen extremes, that indicate a “substantial intensification of pollen seasons in North America over the 1990-2018 period.”
These increases in pollen loads are occurring about 20 days prior to the formal pollen season start date and lengthen the pollen season by about a week.
In modeling the potential relationship between pollen loads and climate change, researchers cross-referenced data from annual pollen integral, spring pollen integral, pollen season start date, and pollen season length, against climate change metrics like temperature, precipitation and carbon emissions in the atmosphere.
Results indicate that temperatures are a strong driver of the amount and timing of pollen released into the air.
“Our results demonstrate that human forcing of the climate system has substantially exacerbated North American pollen seasons, particularly for pollen season duration and spring pollen integrals,” the report reads. “These findings can also inform ongoing efforts to include prognostic pollen models within Earth system models to make spatial and temporal projections of pollen seasons under future climate scenarios and when combined with seasonal and near-term climate forecasts may enable seasonal pollen forecasts, similar to crop yield forecasts.”
In terms of public health consequences, the report underscores that pollen exposure can provoke a sensitivity in children that can lead to allergic asthma in adulthood. This can lead to larger public health problems as pollen season is potentially intensified and lengthened alongside climate change.
“We hypothesize that climate-driven changes in spring and/or annual pollen integrals would have important implications for spatial and temporal patterns of allergy and asthma prevalence and associated medical costs,” the authors write.