The season for large fires in Southern California is projected to lengthen in a changing climate

Chunyu Dong, A. Park Williams, John T. Abatzoglou, Kairong Lin, Gregory S. Okin, Thomas W. Gillespie, Di Long, Yen-Heng Lin, Alex Hall & Glen M. MacDonald

Southern California is a biodiversity hotspot and home to over 23 million people. Over recent
decades the annual wildfire area in the coastal southern California region has not significantly
changed. Yet how fire regime will respond to future anthropogenic climate change remains an
important question. Here, we estimate wildfire probability in southern California at station
scale and daily resolution using random forest algorithms and downscaled earth system
model simulations. We project that large fire days will increase from 36 days/year during
1970–1999 to 58 days/year under moderate greenhouse gas emission scenario (RCP4.5) and
71 days/year by 2070–2099 under a high emission scenario (RCP8.5). The large fire season
will be more intense and have an earlier onset and delayed end. Our findings suggest that
despite the lack of a contemporary trend in fire regime, projected greenhouse gas emissions
will substantially increase the fire danger in southern California by 2099.

Citation: Dong, C., Williams, A.P., Abatzoglou, J.T. et al. The season for large fires in Southern California is projected to lengthen in a changing climate. Commun Earth Environ 3, 22 (2022). https://doi.org/10.1038/s43247-022-00344-6