Over the past several decades, wildfire activity across western North America has increased. We’re seeing larger fires, they’re burning more severely, and they’re happening over a lengthening fire season. As these damages from wildfires and other impacts of climate change mount, people are asking the question of who bears responsibility for these changes? 

Previous research had connected increasing fire activity in the western US and western Canada to human-caused warming, human-caused climate change. So with this study, we wanted to take that a step further and say, “How did the fossil fuel industry contribute to these changes?”

What we did in this study was attribute a portion of the increase in fire-danger conditions and cumulative burned area across the western US and southwestern Canada to emissions that you can trace back to 88 of the world’s largest fossil fuel producers and cement manufacturers. What we found is that those fossil fuel producers and cement manufacturers are responsible for almost 40% of the area of western US and southwestern Canadian forests that has burned since mid-80s, and they’re responsible for about half of the increase in fire-danger conditions that’s happened over the last century.