Crews carrying out a prescribed burn in California's San Bernardino National Forest.
Enlarge / Crews carrying out a prescribed burn in California’s San Bernardino National Forest.

Whenever wildfires rip through an area, splashing nightmarish scenes across the evening news, people who live elsewhere seem to have a lot of suggestions. Why don’t they log the forest so there’s less to burn? Why don’t they get millions of goats to graze the brush? Why live in such a dangerous spot? But as with most things, there are usually complications when you look closer.

A new study led by Stanford’s Rebecca Miller analyzes one option for limiting fires in California: prescribed burns. The researchers interviewed experts in state government, federal agencies, non profits, and academia to find out what barriers are preventing greater use of prescribed burns.

Burning to avoid burns

Prescribed burns utilize low-intensity fires during favorable weather to safely remove some of the fuel that has accumulated on the ground—fuel present partly as a result of our past practice of putting out wildfires as aggressively as possible. It’s often combined with mechanical thinning of brush and trees that serve as “ladders” for fires to climb into treetops, with the resulting brush piles burned later. The researchers say that about 20 percent of the state—20 million acres—could benefit from prescribed burns to reduce the wildfire hazard. But California is not currently on pace to complete that monumental task any time soon.

Prescribed burns can be done by individuals, the state, or federal staff, depending on who owns the land. Individuals can either get permits from CAL FIRE and their local air board—and assume legal liability for any mistakes—or contract with CAL FIRE to do the work. All of these groups have to get air board approval to minimize air quality hazards in the surrounding area, primarily by working on days with ideal weather.

The researchers noted that permit requests have been on the rise, with the area planned to be burned each year doubling since 2013. But only about one-half to one-third of that area actually gets burned—almost entirely due to the US Forest Service falling short of its annual plan.

So what holds the Forest Service back, and why aren’t the planned areas larger? At around 18,000 acres burned in 2018, it would take quite a while to work through the backlog, which now totals 20 million acres.

The three Rs

The researchers found three types of barriers: risks, resources, and regulations. In terms of risk, the fear of liability seems to be preventing many private landowners from considering burns. In 2018, the state created a training certification, and a protection from liability for those who complete it and follow safety procedures. The researchers say that more programs like this could help.

The resource-related barriers can largely explain the gap between plans and actual area burned. Responding to uncontrolled wildfires obviously takes precedence over prescribed burns, both in terms of staffing and funding. CAL FIRE, for example, hires seasonal staff focused on the fire season—which isn’t the best time of year to be attempting prescribed burns. And the US Forest Service has had to use much of its fire budget on active wildfires, diverting funding from prevention. Add in a demographic wave of retirements among fire managers, and staff availability has been limiting.

As is true elsewhere, mechanical thinning efforts in California have suffered from the tension between financial incentives for those doing the work and optimal thinning techniques. Private logging operations would like to target the largest trees, ignoring the small stuff that won’t yield lumber. But thinning operations focus on the small stuff, greatly reducing the profit potential.

Finally, there are the regulation-related barriers. Air board approval is one bottleneck. The experts interviewed felt that the working definition of “acceptable weather conditions” has been strict, which can cut short multi-day burn plans. There are also many local air boards around the state, and a lack of consistency can create problems for burn projects that have to involve more than one of them.

There’s some friction in that the particulate pollution and carbon dioxide emissions of prescribed burns are counted as human-caused, while emissions from wildfires go in a separate category. There’s no offset for prescribed burns reducing potential wildfire emissions.

It’s also true that burns supported by state or federal grants have to undergo additional environmental reviews, which can sometimes hold up projects past windows of opportunity. The researchers say that the experts they talked to felt these reviews are designed for larger projects and don’t work well with prescribed burns. They were also leery of weakening environmental protections, though, so there was no clear recommendation.

The researchers noticed, unsurprisingly, that the California state legislature tends to introduce more wildfire bills following major disasters—of which there have been plenty in the last few years. Many recent bills have focused on addressing roadblocks like liability concerns. But in order to treat something like a million acres of land each year, the researchers say more strategies (and money) will have to come out.

Hiring dedicated staff during the prescribed burn season would be a good start. And real financial incentives for landowners to carry out burns, or for logging contractors to cut brush, could get some wheels rolling. The researchers also suggest that CAL FIRE’s legal requirement to suppress active fires on state or private land could be eliminated, giving them the ability to allow non-dangerous fires to burn when that makes sense, as the Forest Service does on federal land.

They write, “Generating the political willpower to make these important policy changes will probably require a combination of administration support, successful burns, collaboration among multiple stakeholders and, unfortunately, more deadly and destructive wildfires.”

Nature Sustainability, 2019. DOI: 10.1038/s41893-019-0451-7 (About DOIs).