I was quoted by CNN journalist Rachel Ramirez about the Union of Concerned Scientist's (Dahl et al (2023))'s study about the impact of fossil fuels on wildfire area burned in the western North America, published on May 16, 2023. Below is an excerpt from the article with my quote, also including a quote from my colleague Jatan Buch who is a postdoctoral scholar in Park Williams' lab.
More than a third of the area charred by wildfires in Western North America can be traced back to fossil fuels, scientists find
By Rachel Ramirez, Writer, CNN Digital
Millions of acres scorched by wildfires in the Western US and Canada — an area roughly the size of South Carolina — can be traced back to carbon pollution from the world’s largest fossil fuel and cement companies, scientists reported Tuesday.
The study by the Union of Concerned Scientists, published in the journal Environmental Research Letters, found that 37% of the area burned by wildfires in the West since 1986 — nearly 19.8 million acres out of 53 million — can be blamed on the planet-cooking pollution from 88 of the world’s major fossil fuel producers and cement manufacturers, the latter of which have been shown to produce around 7% of all carbon dioxide emissions.
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One metric they focused on was the region’s so-called vapor pressure deficit — or how thirsty the atmosphere is for moisture. It is a key indicator of fire danger and drought, Phillips said, and measures how much the air is sucking moisture out of soil and plants, which then ultimately become fuel for wildfires.
The methodology is “simple,” said Caroline Juang, researcher with the Lamont-Doherty Earth Observatory at Columbia University.
“The study takes what we know about the strong relationship between climate and burned area, and extends this understanding to the role of big fossil fuel emitters,” Juang, who is not involved with the study, told CNN. “The authors use how global mean temperatures scales with [vapor pressure deficit] and then looks at how changes in [vapor pressure deficit] will change burned areas.”
The researchers also accounted for aerosol pollution, which unlike planet-warming gases like carbon dioxide or methane, reflects sunlight back to space and has a cooling effect. Major oil and gas companies contribute roughly two-thirds of total industrial aerosol emissions, according to the study, which used fossil fuel emissions data through 2015, the latest available, and held figures constant from 2015 to 2021.
Jatan Buch, a postdoctoral research scientist in the Lamont-Doherty Earth Observatory at Columbia University, who was also not involved with the study, said that while vapor pressure deficit is the leading driver of year-to-year variability in burned area across the region, other factors play a role and should be examined in future studies. According to the study, those include precipitation and snowpack conditions and prescribed burns and fire suppression efforts that have led to a buildup of vegetation that help fuel fires.
The report also noted that development and growth contributed to a higher risk of human behavior-caused fires, with more people and property in harm’s way.
Read the full article on CNN