Wildfires exacerbated by climate change account for thousands of deaths annually and incur massive economic costs in the U.S., as highlighted by a recent study. Published in Nature Communications Earth & Environment, this research reveals that from 2006 to 2020, climate change was a component in approximately 15,000 deaths due to wildfire-related fine particulate matter and resulted in about $160 billion in economic costs. Annual mortality fluctuated between 130 to 5,100, with Oregon and California experiencing significant impacts.
Nicholas Nassikas, a co-author of the study and Harvard Medical School professor, emphasized the increasing frequency of wildfire smoke events. The research team sought to clarify the implications of these occurrences, particularly concerning mortality, the most severe health outcome. Lisa Thompson from Emory University praised the study for its unique approach in isolating climate change’s effects on mortality.
The study mainly focused on deaths connected to fine particulate matter, or PM2.5, a significant byproduct of wildfire smoke. These microscopic particles can infiltrate the lungs, leading to short-term discomfort and severe long-term health issues, especially affecting vulnerable groups such as children, pregnant women, the elderly, and outdoor workers. Reports indicate PM2.5 contributes to 4 million global deaths annually.
Emerging evidence suggests PM2.5 from wildfires is particularly harmful compared to other pollution sources. When fires penetrate urban areas, burning hazardous materials like vehicles, the situation worsens. Numerous studies link human-induced climate change, primarily from fossil fuel combustion, to increased wildfires in North America. The trend of global warming intensifies droughts, especially in western regions, extracting moisture essential for plant life and subsequently fueling fires. This, coupled with rising temperatures, heightens wildfire occurrence, scale, and associated smoke output.
Jacob Bendix from Syracuse University expressed dismay but was not surprised by the study’s findings, acknowledging their significant implications and emphasizing the broader impacts of wildfires beyond directly affected areas. The researchers used modeling and existing data to assess the area burned due to climate change by comparing actual climate data during wildfire events from 2006 to 2020 with hypothetical conditions void of climate change.
They further calculated PM2.5 levels from climate-driven wildfires and estimated mortality numbers, assigning 10% of the total 164,000 wildfire-PM2.5-related deaths from 2006 to 2020 to climate change. Mortality rates were noticeably higher in the western regions.
Stanford University’s Marshall Burke commended the correlation between climate change and burnt areas but remarked on the complexities of linking this to smoke production due to unpredictable wind patterns. He questioned how these estimates matched up with broader air pollution-related mortality but found the study’s methodology sound overall. Meanwhile, Patrick Brown from Johns Hopkins University raised concerns that the study’s focus might misguidedly suggest reducing carbon emissions as the sole remedy, overlooking crucial immediate interventions like prescribed burns or better ignition-source regulations.
Nassikas acknowledged land management techniques like prescribed burns but stressed the necessity of reducing greenhouse gas emissions to curb deaths from wildfire smoke, stressing awareness and subsequent actionable solutions at personal, community, and global levels are critical.