Summer might be over, but California is currently facing a wildfire outbreak so severe that California Governor Gavin Newsom declared a state of emergency, citing “historic” winds and “unprecedented” fire weather conditions.
The Kincade fire, which is wreaking havoc north of San Francisco, has burned over 73,000 acres in the state’s iconic wine country. As fires rage 300 miles north, Southern California’s Getty fire has burned over 600 acres in West Los Angeles and is poised for greater destruction. The area is scrambling to grapple with its own potentially catastrophic weather, as a potentially record-setting Santa Ana wind event sweeps in Tuesday night.
Cal Fire officials are saying the Kincade fire could burn for “weeks if not months”—unusual considering that the normal summer wildfire season was considered “calm.” The National Weather Service, in an unprecedented move, has issued an “extreme red flag warning” for residents of much of Los Angeles and Ventura counties near the Getty fire as winds pick up and threaten to spread the fire farther and faster.
On top of all of this, nearly one million California residents are without power after the Pacific Gas and Electric Company shut off power in hopes of preventing additional fires from starting. The company has been accused of being responsible for multiple major fires, including two over the weekend in the Bay Area, when compromised power lines and high winds combined to create dangerous results in spite of intentional blackouts in nearby areas.
If you feel like California’s problem with wildfires keeps getting worse, you’re right. Fifteen of California’s 20 largest fires on record have occurred in the past two decades, and scientists find climate change to be the unambiguous cause fueling these bigger, more destructive fires.
A study published in July found the amount of land wildfires burn in California annually has increased by 500 percent since 1972. The researchers analyzed nearly 40,000 wildfires over that time period and found an increase in daytime temperatures was a major factor in why more land was burning.
The researchers believe that California’s warm season days have seen temperatures increase by nearly 3 degrees Fahrenheit since the '70s. While other environmental factors are also at work, at the most basic level the increase in temperature contributes to an arid environment—meaning the plants and soil become dried out—which makes it more likely that fires will consume larger areas.
Alex Hall, a professor of atmospheric and oceanic sciences and director of the Center for Climate Science at UCLA, told The Daily Beast that temperature increases driven by climate change are certainly a major factor.
“Especially in the last five years, there’s been a dramatic increase in the intensity of wildfires. That is, in part, driven by an increase in temperature,” Hall said. “The winds tend to be drier, and they are more likely to spread fire. Warmer temperatures also dry out vegetation more quickly.”
The state has also experienced longer dry seasons recently. California’s fire season used to start part-way through the summer and end sometime in the early fall when the wet season began. As we’re seeing now, the dry season has at times extended into November or December in recent years, expanding the opportunities for catastrophic fires to engulf large parts of the state.
“The moment when the rainy season begins is the moment when the fire season largely comes to an end, so there is definitely a timing factor there,” Hall said, noting that there is some variability in the start of the rainy season from year to year.
But more precipitation can complicate things even further. During wetter years, there’s more opportunity for vegetation to grow, creating fuel that could burn during the next dry year. In a study published in Nature Climate Change last year, Hall examined this phenomenon, finding that California experienced “extreme wetness during the 2016–2017 winter” after a number of dry years. The state went on to experience disastrous fires in the years that followed.
“There’s a huge swing between the summer and the winter, in terms of precipitation in California, and then there are huge swings from winter to winter in how much precipitation is received,” Hall said. “That variability is projected to increase in the future due to a changing climate.”
Scientists expect that dry years in California will soon be drier and the wet years will soon be more wet. Hall explained that there could be multiple wet winters in a row, producing dangerous growth.
While some effects of California’s destructive fire cycle appear to be inevitable, what we can try to do now is mitigate the severity events like the fires raging in both halves of California.
“A certain amount of climate change is inevitable,” Hall said. “But that certainly doesn’t mean we shouldn’t do anything about reducing greenhouse gas emissions. Because if we don’t, the outcomes are just far worse.”