Climate change has — already — increased the risk of explosive wildfire growth in California by 25%, a study published in Nature finds. That climate change, mainly caused by the extraction and combustion of fossil fuels, is supercharging wildfires is well-established. The study examined 18,000 individual wildfires between 2003 and 2020 and assessed the relationship between daily temperatures and extreme daily fire growth (more than 10,000 acres per day).

Similar to how just one extra inch of flooding can dramatically increase flood damage if it reaches a home’s lowest electrical outlet, the researchers found climate-fueled heat (and thus drying of vegetation) can tip fire risk into extreme territory. “If conditions were pretty dry but not super dry,” Patrick Brown, the study’s author, told the LA Times, “the background warming kind of pushed you over a critical threshold of drying or aridity and caused a large increase in the probability of extreme daily fire growth.” (LA Times $, NPR, KSBW; Climate Signals background: Wildfires)