Gov. Jerry Brown was quick to attribute the numerous wildfires statewide to climate change.
However, while not necessarily disputing Brown’s claims, a KQED report from Jacob Margolis provides quite a bit more nuance to the causes behind the fires.
According to the report, a confluence of factors, including high winds, less precipitation than usual, and an increased amount of fuel to burn, contributed to the optimal fire conditions we are now witnessing.
In the particular instance of the Thomas Fire, still burning with little containment near Ventura and Santa Barbara, Santa Ana winds drove the fire as it grew rapidly in its early days. These winds, which reached gusts of up to 60-70 miles per hour, typically last two or three days. This time around, they lasted more than five.
According to Margolis: “The stronger and longer-lasting winds are a result of a particularly strong, particularly cold high-pressure ridge sitting east of the Rockies. As the wind travels from that area of high pressure across the Great Basin towards areas of low pressure along California’s coast, the wind speeds up, compresses and slams into Southern California.”
He then cites a comment from UCLA professor Alex Hall, who claims that there is evidence that climate change will cause both increases and decreases in severity of these winds. This makes their attribution to climate change less certain.
Climate Change Produces Weather Extremes
One factor that holds closer ties to climate change is the increasingly extreme wet-dry cycles for precipitation.
Margolis says, “It’s widely accepted that along with climate change we’ll experience extreme dry periods, punctuated by short, extreme periods of precipitation.”
In addition, he points out that, despite improved rainfall this past winter, Ventura County, where the Thomas Fire began, is still classified as experiencing moderate drought.
If we had not received that slightly above-average rainfall last year, Margolis notes, there would also now be less fuel for the fires to burn.
The rainfall from last year, which led to abundant new vegetation, coupled with the subsequent dry months, created a prime environment for uncontrollable fires to break out with plenty of material to burn.
To read the full report from Margolis, click here: Southern California Is Burning — Is Climate Change to Blame?