California Gov. Jerry Brown and former Vice President Al Gore lead the list of those blaming climate change for Southern California’s devastating wildfires, calling them “the new normal,” but others insist the science just isn’t there.
That includes climate scientists such as University of Washington meteorologist Cliff Mass, who moved to extinguish the “now normal” narrative by arguing that the data “strongly suggests there is no credible evidence” that global warming is fueling this fall’s California coastal wildfires, and that claims to the contrary are “baseless, if not outright wrong.”
“The bottom line of all this is that observations and the best scientific reasoning do NOT suggest that global warming is enhancing CA coastal wildfires through effects on temperature and precipitation,” Mr. Mass said Monday in a post on his weather and climate blog.
He and others have pointed to the heavy precipitation earlier this year in California after five years of drought, which resulted in high vegetation growth that feeds the flames.
“The destructive fires in California are not unexpected given the wet winter last year and resultant plant growth, followed by hot and dry weather since then in which the vegetation dried out,” University of Colorado Boulder meteorologist Roger A. Pielke Sr. said in an email.
Then there is the human variable. Just as people are responsible for emitting carbon dioxide into the atmosphere, they also are known for setting fires.
“An important issue is the extent humans have deliberately or inadvertently started the fires,” Mr. Pielke said. “If these were not started by people (including sparks from power lines), how many fires would there have been naturally? Probably none.”
Scientists are rejecting arguments by a rash of politicians and media outlets linking climate change to blazes that have charred more than 256,000 acres so far in Los Angeles, Santa Barbara, San Diego and Ventura counties, according to reports from the National Interagency Fire Center.
The largest of the five active wildfires, the Thomas Fire north of Santa Paula, has burned 230,500 acres and destroyed nearly 800 structures as gusty Santa Ana winds push the flames farther west into Santa Barbara County and threaten the towns of Montecito and Summerland, according to state firefighting agency Cal Fire.
Mr. Brown declared Saturday that Californians should expect winter wildfires because of the effects of drought and climate change.
“This is the new normal,” Mr. Brown said at a news conference after surveying damage in Ventura County. “We’re about ready to have firefighting at Christmas. This is very odd and unusual.”
Mr. Gore conveyed the same message last week during his Climate Reality Project’s “24 Hours of Reality,” listing “more destructive and widespread wildfires” as one of the consequences of climate change and specifically the damage caused by the Southern California blazes.
“You know, events like this are now reported daily on the news with a terrifying drumbeat of regularity, the so-called ‘new normal,’ but it’s not normal at all, and we have to speak up and act,” said Mr. Gore.
Fueling the narrative are stories such as those in The New York Times, headlined “In a Warming California, a Future of More Fire,” while InsideClimate News reported “As ‘Epic Winds’ Drive California Fires, Climate Change Fuels the Risk.”
“Southern California fires are destructive and unprecedented — and a sign of things to come,” said an article in the Palm Springs Desert Sun.
“We’ve seen really wet falls and winters lately too, and then we’ve seen really dry ones. And that’s the hallmark pattern you expect to see with climate change,” University of California-Merced fire ecologist LeRoy Westerling told the Desert Sun. “We had a much longer season of high fire risk [this year] because we haven’t gotten the rain.”
The articles cite California’s record summer heat, but Mr. Mass argued that hot weather driven by greenhouses gases would not have made a difference because “grasses, shrubs and other fuels will be dry by the end of summer and during fall, no matter what.”
“So even if the summer/fall temperatures rose and the conditions dried further under global warming, IT WOULD NOT MATTER,” he said. “Without any additional warming, the fuels in late summer and fall are dry enough to burn over coastal California and always have been.”
John Abatzoglou, associate professor of geography and climate at the University of Idaho, said the prolonged Santa Ana winds whipping up the wildfires would not have made news if the rain came first.
Did global warming play a role? “We don’t have any mature science [that I’m aware of] that would implicate climate change as being behind the delay in the autumn rains,” Mr. Abatzoglou said in an email.
“However, the warmer temperatures (including a bump tied to climate change) would play some role in drying fuels out,” he said. “There is some research that suggests that Santa Ana winds events under climate change may bring more extreme drops in humidity, which aid in fire growth.”
Mr. Abatzoglou cited “documented increases in fire activity and the length of the fire season across the western U.S. (and globally) over the past 3-4 decades, with some of this tied to climate change,” which is consistent with the National Climate Assessment’s finding of more large forest fires since the 1980s.
Is that because of climate change? Not according to House and Senate Republicans who blame the uptick on the increasingly hands-off approach to tree-cutting on federal lands and have sponsored legislation to push more aggressive forest management.
One such bill, the Resilient Federal Forests Act, passed the House on Nov. 1 by a vote of 232-188.
At the same time, evidence suggests that wildfires were worse before World War II.
Bjorn Lomborg, president of the Copenhagen Consensus Center, compiled data from 1926-2017 showing that the acreage burned by U.S. wildfires has dropped fourfold since peaking in the 1930s, which was posted on the skeptics’ website Climate Depot.
David B. South, emeritus forestry professor at Auburn University, told the Senate Environment and Public Works Committee in 2014 that eight of 10 “extreme megafires” in the lower 48 states since 1850 occurred during cooler-than-average decades.
“These data suggest that extremely large megafires were 4-times more common before 1940 (back when carbon dioxide concentrations were lower than 310 ppmv),” Mr. South said in his written testimony. “What these graphs suggest is that we cannot reasonably say that anthropogenic global warming causes extremely large wildfires.”
Mr. Mass pointed to a 2014 research paper in the American Geophysical Union journal showing that major coastal California wildfires have declined since 1984.
“Totally consistent with everything I have described above,” Mr. Mass said. “Totally inconsistent with the claims of Governor Brown, some climate activists, and too many media outlets.”
If there is any point on which there may be a scientific consensus, it’s that the relationship between Western wildfires and rising greenhouse gas emissions in the atmosphere is nothing if not complicated.
“As to whether this is a ‘new normal,’ it is easy (and inaccurate) to blame climate change just from added CO₂,” said Mr. Pielke, “when in reality the reasons for the fires and the damage they are causing are more complex.”