Recent severe wildfires in California fit into a broader trend of increasing burn area and damage over the past 40 years, according to a new report.
It’s clear that wildfires have become more intense over the last few years. But how much more? That’s a difficult question, researchers say, because when it comes to science, you can’t study what you can’t measure.
To explore the issue, researchers compiled a new dataset of damage that California wildfires have caused as part of a broader project on future land use in the state.
“It occurred to us to these data would be of interest to a lot of people, so we decided to write them up in a brief,” says coauthor Andrew Plantinga, an economics professor at the Bren School of Environmental Science & Management at the University of California, Santa Barbara.
The team analyzed two sources of data from Cal Fire, the state agency in charge of firefighting. The first was a dataset on fire perimeters and the second included estimates of wildfire damages for each fire.
The researchers used the information to calculate trends involving the number and timing of fires throughout the state by time of year.
They also calculated the total area burned and specifically identified the amount of wild land urban-interface burned. These refer to areas where houses intermingle with wild land vegetation, and are of particular concern to those studying wildfire.
“The main finding is that the recent severe fires in California—including the Thomas fire in 2017 and the Camp fire in 2018—are part of a trend in California over the past four decades,” Plantinga says. “The trend is toward more wildfires that burn larger areas and cause more damage.”
The number of acres California wildfires burn per year has not only increased, but also accelerated, the report shows.
And the increase doesn’t only occur during the season’s peak, from June through October. California is also seeing a longer fire season, with more acres burned in late fall than in the past.
While greater burn areas don’t automatically translate to greater damages, the researchers found that these, too, have risen.
“I expected the recent severe fires to be outliers, and they are,” says Plantinga, “but it’s also clear that they represent part of a trend toward larger and more damaging fires.”
The report is part of a larger effort to estimate the costs associated with a business-as-usual approach to development in California, when considering the potential impacts of climate change.
The team had previously found that interventions on natural and working lands—like forests, farms, and rangelands—can contribute 2.5 times the emissions reductions by 2050 as residential and commercial sectors combined.
What’s more, for every dollar spent on implementing land-use strategies, close to fifty cents would be recouped in economic benefits. And that’s without accounting for other positive impacts, the previous report states.
Rather than another deep analysis, the group’s recent publication mostly served to aggregate and summarize important information on fire trends.
“Our goal was to put the numbers out there and let people draw their own conclusions,” Plantinga says, adding that the group does not plan to recommend particular actions or propose factors that may be causing the trend.
“Nevertheless, we think the data are an important input to policy discussions and to future research.”
The report is available on the Environmental Market Solutions Lab website. Additional coauthors are from the Nature Conservancy and UC Santa Barbara.
Source: UC Santa Barbara