Articles | Volume 23, issue 2
Research article
 | Highlight paper
01 Feb 2023
Research article | Highlight paper |  | 01 Feb 2023

Projected increases in wildfires may challenge regulatory curtailment of PM2.5 over the eastern US by 2050

Chandan Sarangi, Yun Qian, L. Ruby Leung, Yang Zhang, Yufei Zou, and Yuhang Wang

Data sets

Wildfire simulation data and codes C. Sarangi and Y. Qian

Hazard Mapping System Fire and Smoke Product NOAA

Model code and software

Wildfire simulation data and codes C. Sarangi and Y. Qian

Executive editor
Wildfires enhance surface PM2.5 concentration and thus adversely affect air quality and human health. Based on online-coupled fire-climate-ecosystem model simulations, this paper projects a nearly 2-fold increase in wildfire-induced summer-mean surface PM2.5 by the mid-21st century over North America. The projected enhancement is substantial even in the less-densely forested eastern US - as already manifested in the poor air quality as observed in June 2023 due to Canadian wildfires -, which is attributed to the transport of smoke from North America as well as positive climatic feedback of smoke on PM2.5. Thus, future regulatory controls on PM2.5 in North America, particularly in the eastern US where anthropogenic emissions are falling, should consider the effect of future increases in wildfires.
Short summary
We show that for air quality, the densely populated eastern US may see even larger impacts of wildfires due to long-distance smoke transport and associated positive climatic impacts, partially compensating the improvements from regulations on anthropogenic emissions. This study highlights the tension between natural and anthropogenic contributions and the non-local nature of air pollution that complicate regulatory strategies for improving future regional air quality for human health.
Final-revised paper