High-severity wildfires that kill large numbers of trees are now burning far more acreage in California than they did four decades ago, according to a UCLA study published Monday. The study, appearing in the journal Proceedings of the National Academy of Sciences, found that the area burned by high-severity fires in California increased thirtyfold between 1985 and 2024, while overall forest acreage burned annually increased tenfold. Researchers said severe fires, which often kill entire stands of trees rather than allowing forests to recover naturally, have overtaken lower- severity fires as the dominant type of forest fire in California. … Researchers linked the trend to increasingly warm and dry conditions associated with climate change, as well as decades of fire suppression that have allowed dense vegetation and underbrush to accumulate in many forests.