WASHINGTON - US climate scientists have quantified for the first time the extent to which greenhouse gases from the world's leading fossil fuel companies have contributed to the fires. Their analysis, published Tuesday in Environmental Research Letters, found that carbon dioxide and methane emissions from the so-called "big 88" firms were responsible for more than a third of the area burned by wildfires in western North America over the past 40 years. years. First author Kristina Dahl of the Union of Concerned Scientists (UCS) said wildfires in the western United States and southwestern Canada have been getting worse for decades: burning more intensely, for longer periods, covering larger areas and reaching higher elevations. To date, the costs of rebuilding and increasing resilience are largely borne by the general public, "so we wanted to better understand the role that fossil fuel emissions have in changing the wildfire landscape," she said. "We really wanted to highlight their role in being able to be held accountable for their fair share of the cost."