Study Shows Fossil Fuel Producers Responsible for Over a Third of Wildfires in Western North America

The world’s largest producers of fossil fuels are responsible for more than a third of the area burned by wildfires in western North America over the past 40 years, according to a study to be published in the scientific journal Environmental Research. Letters.

The fires ravaging the western United States and southwestern Canada have worsened for several decades, explains to AFP, the main author of the study, Kristina Dahl, of the Union of Concerned Scientists. They spread with more intensity, destroy larger areas, reach higher altitudes and last for several seasons.

So far, the public has borne the cost of rebuilding and protecting against the new normal that has become the risk of fire, “this is why we wanted to better understand the role played by the emissions of large fossil fuel companies” in this development, she continued. “We wanted to highlight their role so that they assume their share of responsibility for the cost” of the fires and their aftermath,” added Kristina Dahl.

Researchers combined observed data and climate models to determine how much carbon dioxide and methane emissions from the 88 largest fossil fuel producers, including ExxonMobil, BP, Chevron and Shell, had contributed to atmospheric drought .

They concluded that these emissions were responsible for an average rise in global temperatures since the start of the 20th century of 0.5 degrees Celsius, half of the observed warming.

This rise in temperature has worsened by 11% the deficit of water vapor pressure in the atmosphere of the western United States.

A high water vapor pressure deficit means that the ambient air absorbs more of the water droplets emitted by plants and soils during photosynthesis, which dries them out and makes vegetation more vulnerable to fires. Recent research shows that as the water vapor deficit increases, the areas ravaged by fires expand.

According to the study by the Union of Concerned Scientists, the destruction of 8 million hectares by forest fires in the western United States and southwestern Canada – the same area as the Czech Republic – – is thus due to the largest producers of fossil fuels and cement.

This represents 37% of the area totally destroyed by wildfires in western North America between 1986 and 2021. The year 1986 was chosen as the benchmark because it is from that year- where data on the area burned by wildfires became reliable.

Among other factors responsible for the multiplication and worsening of the fires, the study notes the abandonment of the ancestral practice of regulating forests by deliberate but limited fires, which has resulted in thicker and more dense undergrowth. likely to catch fire.

Urbanization in wooded areas is also a factor cited by the researchers, as it increases the risk of accidental fire starting.