During the 2018 Camp Fire, which lasted 17 days and killed 85 people, residents of nearby Northern California communities breathed in enough smoke to equal half a pack of cigarettes. Many of the questions being asked then sound eerily familiar today. Should schools close? Who should wear a mask? Then as now, answers from officials often made the situation more confusing, not less. “Even county to county or community to community, you got very different information on what you should be doing,” says Marshall Burke, a Stanford University professor of earth system science.
The Stanford team set out to simplify both processes. Their approach—published Monday as a working paper by the National Bureau of Economic Research—starts with analyzing satellite records to see how past fires and their smoke have spread, then combines that data with regular on-the-ground air-monitor readings of fine particle pollution (called PM 2.5, for particulate matter smaller than 2.5 millionths of a meter) to generate hyper-specific air quality estimates.
Applying their method generated some surprising results. As wildfires become more frequent due to climate change, the researchers found, the increasing amounts of smoke may harm Americans nearly as much as rising temperatures. “That’s crazy, right?” Burke says. “We hadn’t even though of that as a key part of the climate impact in this country.”