Modeling Pollen Emission Variations over the Continental U.S. with Climate Change

Abstract:

Atmospheric conditions (e.g. temperature, humidity, precipitation and carbon dioxide concentration) is known to affect the release of pollen from vegetation, and the timing and magnitude of pollen released is expected to be altered by climate change. Here we use a pollen emission model to simulate pollen emissions and their responses to climate change of 13 most prevalent wind-pollinating taxa in the United States. The pollen model is driven by meteorological parameters from Climate Model Intercomparison Project 6 (CMIP6) for two climate change scenarios (Shared Socioeconomic Pathways (SSPs) 245 and 585) to simulate pollen emissions over the continental U.S. for historical (1995-2014) and future conditions (the mid-century (2040-2059) and the end of the century (2081-2100)). Compared to the historical period, almost all of the pollen seasons shift earlier in the year, with a longer duration in the future (mean of 1-12 days, depending on vegetation type). In some regions such as the northeastern US, the seasonal shift leads to the overlap of spring flowering seasons in multiple taxon, which increases the pollen daily maximum emission. Airborne pollen is a major cause of allergic diseases and regional climate, and the extended pollen seasons and the elevated maximum daily pollen emission due to climate change may worsen allergenic conditions in the future.