Impacts of climate change on land management and wildland fire smoke in the Southeastern United States

Abstract Although prescribed fire is frequently used in the Southeastern United States, land managers in the region and across the country plan to expand burning to mitigate wildfire and achieve other ecological goals. However, smoke management is often considered a barrier to prescribed fire. Additionally, climate change will likely affect the frequency of acceptable meteorological conditions for prescribed burning, potentially restricting the use of the practice. Here, we examine the air quality impacts from prescribed fire and wildfire in the Southeastern U.S., the populations affected by smoke in the region, and how these impacts may change under climate change. We rely on projections of wildfire burn area and climate-driven shifts in the frequency of meteorological conditions adequate for prescribed burning, as well as a survey of Southeastern land managers investigating their anticipated response to these changes. Based on this information, we use chemical transport modeling to assess the contributions of wildfire and prescribed fire to air pollution, and project how smoke impacts may vary due to climate change and different land manager responses. We find that prescribed fire is responsible for a significant fraction of regional particulate matter pollution. Populations exposed to the most smoke tend to have higher fractions of people of color and low income. Depending on how land managers respond to changes in atmospheric conditions under climate change, prescribed fire smoke may decrease slightly in the areas with the heaviest burning or increase across much of the Southeast. Projections also show that climate-driven changes in wildfire and prescribed burning may impact compliance with recently updated air quality standards. The analysis assesses the potential consequences of climate change on air pollution over a region in which wildland fire is extensively managed, providing insight into land management strategies that call for increased application of prescribed fire.