Summer wildfire seasons in California routinely break records. The average summer burn area in forests in northern and central portions of the state have increased fivefold between 1996 and 2021 compared to between 1971 and 1995.
Although the drivers of increased temperature and dryness are known, the contribution of human-caused climate change to wildfire activity, relative to natural climate variation, is unclear.
However, a new study by a Lawrence Livermore National Laboratory (LLNL) scientist and collaborators shows that nearly all the recent increase in summer wildfire burned area is attributable to human-caused (anthropogenic) climate change. Anthropogenic simulations yielded burn areas an average of 172% higher than natural variation simulations. The research appears in the Proceedings of the National Academy of Sciences.
The team, led by Marco Turco from the University of Murcia, Spain, modeled the climate drivers of summer wildfire activity in California, both with natural climate variation alone and with anthropogenic climate change effects.