Air pollution from western wildfires could triple by end of century
(CN) — Researchers at Princeton University determined the air pollution from wildfires across the western U.S. could as much as triple by 2100 without climate change mitigation efforts.
According to a study published Monday in the journal Proceedings of the National Academy of Sciences, the researchers combined results from multiple climate models to predict the different amounts of particulate pollution after three climate change mitigation scenarios. Though a high degree of climate change mitigation would avoid the severest effects, the findings indicate the region is headed for an increase in air pollution stemming from wildfires.
“In the next 20 to 30 years, fine particle pollution over the U.S. Pacific Northwest will increase under all scenarios, even under strong mitigations,” said Meiyun Lin, a co-author of the study.
Even in the strongest climate change mitigation scenario, where the world reaches net-zero carbon emissions around 2050, Lin said wildfire particle pollution will increase by as much as 50% by the middle of the century and then level off through 2100.
Lin said the most “extreme scenario is the pathway we want to do everything to avoid.” Under that climate change mitigation scenario, a fossil fuel-driven economy will double carbon emissions by 2050 and drive them up further throughout the century. This would result in the particle pollution from wildfires doubling or tripling by 2100.
The intermediate climate change mitigation scenario the researchers used would see carbon emissions remain at their current levels in 2050 with global emissions reaching net-zero around the end of the century. In that case, the particle pollution from wildfires will still “almost double compared to the present levels,” according to Lin.
The projected increases in air pollution could have significant adverse effects for people, particularly in the Pacific Northwest where the research shows the effects will be most pronounced. Fine particle pollution from wildfires can be inhaled and impact public health.
“Severe particle pollution can really threaten public health and pose challenges for regional air quality management,” said Lin.
The research comes after a series of devastating fire seasons in Northern California and across the western United States, which left behind considerable human toll, financial costs, environmental destruction and added pollution. Lin said their research indicates that without adopting the strongest climate change mitigation scenario, the severe pollution seen after the 2017 to 2021 wildfire seasons could continuously recur every three to five years.
“One of the key focuses of our study is to try and understand how these recent extremes will recur,” Lin said. “We find that severe particle pollution like what occurred during these recent extremes in the western U.S. will recur every five years, even under the intermediate climate change scenario.”
Going forward, Lin said she and her fellow researchers are interested in investigating how other pollution from wildfires mixes with urban pollution to trigger “severe ground-level ozone pollution.”
“It’s a complex relationship between fire emissions and ozone formation,” Lin said, adding they hope to build a model that “will allow us to investigate how the mixings of organic emissions from wildfires with other pollution contributes to severe ozone pollution in cities. That will be the next step.”