Study Shows Climate Crisis Driving Increase in California Summer Wildfire Damage

Nearly all the recent increase in land area engulfed by California summer wildfires is attributable to human-caused climate change, a study published Monday revealed.

The study—published in the peer-reviewed journal Proceedings of the National Academy of Sciences by researchers at Lawrence Livermore National Laboratory (LLNL), multiple University of California campuses, and three Spanish universities—quantified the influence of anthropogenic climate change on recent summer forest burned area in the nation's most populous state.

"The 10 largest fires in California history have all occurred in the past two decades, and five of those have happened since 2020," noted University of California, Irvine professor of civil and environmental engineering and study co-author Amir AghaKouchak.

"The results show the role of human-caused climate change in driving fire activity and highlight the need for protective adaptations against summer wildfire seasons."

LLNL scientist and study co-author Don Lucas said that "we show that nearly all of the observed increase in burned area in California over the past half-century is attributable to human-caused climate change."

"The results show the role of human-caused climate change in driving fire activity and highlight the need for protective adaptations against summer wildfire seasons," Lucas added.

According to the study's abstract:

Record-breaking summer forest fires have become a regular occurrence in California. Observations indicate a fivefold increase in summer burned area (BA) in forests in northern and central California during 1996 to 2021 relative to 1971 to 1995. While the higher temperature and increased dryness have been suggested to be the leading causes of increased BA, the extent to which BA changes are due to natural variability or anthropogenic climate change remains unresolved... Our results indicate that nearly all the observed increase in BA is due to anthropogenic climate change... We detect the signal of combined historical forcing on the observed BA emerging in 2001 with no detectable influence of the natural forcing alone.

"These findings strongly indicate that the observed increase in BA was primarily due to increased fuel aridity and not due to simultaneous variations in nonclimate factors such as human effects on ignitions, fire suppression, or by altering land cover," the study states.

In 2020, the CEO of PG&E, California's largest utility, pleaded guilty to 84 counts of involuntary manslaughter in connection with the 2018 Camp fire, which was caused by the company's faulty equipment and incinerated the town of Paradise. The utility has also been implicated in numerous other California wildfires.

The study's researchers used climate models to forecast BA spread in California's future.

"Our paper makes it clear that the problem is ours to fix and that we can take steps to help solve it."

"We found that we can expect as much as a 50% increase in burned area from 2031 to 2050 relative to the past few decades," AghaKouchak said.

"Our paper makes it clear that the problem is ours to fix and that we can take steps to help solve it," he added. "By acting now to reduce our carbon dioxide emissions and pursue more sustainable transportation, energy production, and agricultural practices, we can reduce the adverse effects of global climate change."