The study reveals that wildfires, exacerbated by rising temperatures and drought, pose a significant threat to even the most fire-adapted forests. A fifth of the giant sequoias in Sequoia and Kings Canyon National Parks were destroyed during the 2020-2021 wildfires, an unprecedented loss for these ancient trees. Without prescribed burns, the risk of catastrophic damage to these ecosystems increases, endangering biodiversity and the survival of some of the planet's oldest living organisms.