Climate change, which makes heatwaves more intense and more frequent, is threatening the California electrical grid as extreme heat drives up energy demand while wildfires threatening transmission lines make supply unstable. More than 24 million people were under a heat alert Monday as California’s grid operator urged customers to limit their electricity consumption.

“[C]limate change and these extreme heat waves happening in the earlier parts of the summer now have forced all of us to do things that we really never imagined just a few years ago,” ISO President and CEO Elliot Mainzer told reporters. In Oregon, the Bootleg Fire is threatening transmission lines moving power from California to the Pacific Northwest, cutting off 5,500 MW from the Golden State. Nearly 60 wildfires are burning from Alaska to Wyoming. In California, the Beckwourth Complex has now burned upwards of 90,000 acres and whipped up a firenado on Saturday — more than twice as many acres have burned in California in the first half of 2021 as burned there in the first half of last year.

“Climate change is real, it’s bad and it’s really affecting our fire weather and our fire danger,” Craig Clements, a professor of meteorology and director of the Wildfire Interdisciplinary Research Center at San Jose State, told the LA Times. “Its fingerprints are all over this stuff.” (Grid pressure: E&E $, LA Times $, TIME, Washington Post $, Bloomberg $; Heatwave: CNN, New York Times $; Firenado: Earther; North American fires: AP, Axios; Record pace: LA Times $, CNN, Democracy Now; Climate Signals background: Extreme heat and heatwaves, Wildfires, 2020 Western wildfire season)