Environment: Assessing the impact of climate change on pollen season length in the US

Plant pollen emissions in the United States could start up to 40 days earlier by the end of the century as a result of climate change, suggests a modelling study published in Nature Communications. These findings show how climate change and pollution can have additional negative effects for human health by extending the season for pollen-related allergies.

Wind-driven pollen production is linked to temperature and precipitation and plays an important role in plant fertilization. Pollen-induced respiratory allergies, such as hay fever, affect 30% of the world population and contributes to economic loss due to missed work days and medical expenditure. Owing to health and economic concerns it is important to understand how climate change will alter plant pollen production and, consequently, seasonal allergies.

Yingxiao Zhang and Allison Steiner combined climate data with socioeconomic scenarios and developed a modelling approach to project changes in pollen emissions in the US at the end of the century (2081–2100), which they then compared to a historical period (1995–2014). The authors found that at the end of the century pollen emissions could start up to 40 days earlier and may also last 19 days longer, increasing the annual pollen emissions over the US by 16–40%. Additionally, the authors added CO2 concentrations to the model and found annual pollen emissions could rise by up to 250% due to anthropogenic pollution.

The authors note that data on how pollen production is affected by CO2 is based on laboratory findings and additional research is needed to quantify its effects in natural settings. They conclude that their findings are a starting point for further investigations into the consequences of climate change on pollen emission patterns and subsequent health implications.