RM: This is 99% Invisible. I’m Roman Mars.
RM: Over the past few days, Californians have watched as the Carr wildfire has raged through the northern part of the state. The fire started a little more than a week ago. Fueled by dry brush, high temperatures, and strong, shifting winds, the fire has moved from a national recreation area into the nearby city of Redding. As of this recording, 6 people have died, 19 people are reported missing, and thousands have evacuated. The fire is only 20% contained.
Wildland fires aren’t new in California, but with climate change, our fire seasons are becoming longer, and fires are becoming bigger and harder to fight. So for the next two weeks, we’re going to look at the issue of wildfire, some design solutions, and just how complicated they can be to implement.
RM: The Santa Ana winds of Southern California are sometimes called the “Devil Winds.” They pick up in the late summer and early fall, sweeping down from the mountains and across the coast. They’re hot and dry and known for creating dangerous fire conditions.
SJ: In late November of 1980, as the Santa Anas blew in at up to 90 miles an hour, an unknown arsonist lit a fire near Panorama Point in the San Bernardino Mountains.
RM: That’s reporter Stephanie Joyce.
SJ: Pushed by the wind, the fire grew and quickly spread down the mountain toward the city of San Bernardino. This is the city’s then-fire chief, talking to a reporter…
(Gerald Newcomb, Chief, San Bernardino FD): Again, we had extremely strong winds, humidity was somewhere about 10.
RM: Another local fire chief said they called in all available resources and still, it wasn’t enough. There was no stopping the fire.
(Duane Mellinger, Chief, Central Valley FD): “All the conditions were just right for what we commonly refer to as a firestorm.”
SJ: In just a few hours, the Panorama fire destroyed hundreds of homes and killed four people. It was one of the worst wildfire disasters in California history at the time.
RM: It was also the fire that would make a young researcher question our entire approach to wildfires, and conclude that we might be able to design our way out of the devastation they cause.
SJ: Jack Cohen was a few years out of graduate school, and a recent transplant to California at the time of the fire. He was working as a research scientist for the Forest Service, studying fire behavior, and he was interested in how the Panorama fire had destroyed so many homes. Especially when there was such an overwhelming firefighting response.
JACK COHEN: a strike team of engines is five engines and they had 20 strike teams coming in right away. There would be a whole block of houses on fire and they could not deliver enough water, so they were calling in more hoses and moving a block down, or two blocks down and losing that, and then moving further and losing that.
RM: So, Jack started listening to the emergency dispatch tapes from the day of the fire.
SJ: Jack is a matter-of-fact kind of guy, a scientist; rational, not emotional. But almost forty years later, he still chokes up when he talks about the desperation he heard in the firefighters’ voices. The tapes are pretty hard to understand but you can hear the emotion.
JC: It was pretty emotional particularly listening to the radio traffic. **pauses//deep inhale**
SJ: Because of how just couldn’t they couldn’t fight it.
JC: Just desperation. Yeah.
RM: For those of us who mostly see wildfires on TV, or in pictures in the paper, it’s easy to imagine that a wildfire is like a tsunami of flames, spreading across the landscape and destroying everything in its path. But Jack knew it wasn’t that simple when he set out to piece together how the disaster had unfolded.
JC: And so one of the things that I did was to look at when the first call came in to dispatch for a fire in this community, where was that call from and where was the wildfire at that time.
WOMAN 1: Okay, there’s a fire approaching our house at 5211 North Sierra.
Dispatcher 1: Okay, ma’am, I want you to just get out of there.
SJ: And as Jack was listening to the tapes, he started to notice a pattern.
FIREFIGHTER 3: 3637 We have at least two roof fires… it looks like three roof fires…
SJ: People were calling in about houses on fire long before the fire front ever reached their neighborhoods.
JACK: The wildfire was still actually on the other side of the ridge, about a half a mile away, burning up the hill.
SJ: These houses weren’t burning because a wall of fire was racing through the community.
RM: They were burning because of something else: the embers. As wildfires burn, they generate embers that are lofted downwind ahead of the main body of the fire. And Jack realized most of the houses that burned had one, extremely problematic feature in common.
JC: As it turns out every house had a flammable wood roof.
SJ: The embers were accumulating in the crevices around the dry wood shingles, and setting fire to the houses from above. Across the street, in a development without wood roofs, most of the houses had survived.
RM: And while that might not seem like a huge epiphany, that houses with wood roofs burned and houses without wood roofs didn’t, for Jack, it was that detail that made him rethink the entire wildfire problem.
SJ: Because when he listened to other people talk about the fire, they weren’t focusing on the wood roofs, they were talking about firefighting. And they were saying nothing could’ve been done. Like this captain at the San Bernardino fire department:
(Fire Captain Jim Knight, San Bernardino Fire Department): “if we woulda had as many as 500 units spread along the whole hillside there to protect those homes, I don’t believe we could have stopped that fire any better than we did under the conditions that we had. The only thing that I feel is that what could have saved those homes would have only been an act of God.
RM: Jack didn’t think that was right. The problem wasn’t the firefighting response. The problem was that the houses were built to burn.
RM: And when Jack shifted his focus, from the fire to the design of the homes, suddenly he found himself wondering if we were framing the whole problem of wildfire in the wrong way.
SJ: He wasn’t the first to have that thought, but he was the first to do extensive research into exactly how homes burn in wildfires.
RM: Some of that work would put him at odds with some of the main firefighting agencies in the U.S. and nearly a hundred years of fire policy and tradition. And even though his ideas are simple and compelling, they still haven’t caught on in the way he hoped they would. Maybe because fighting fires is as much a social and political problem as it is a technical one.
SJ: Do you feel frustrated most of the time?
JC: Yeah, most of the time.
RM: For most of this country’s history, our approach to wildfire has been driven by the sentiment “fire is bad.”
SJ: Before colonization, many Native American tribes set fires intentionally, to regenerate wild plants, and to create grasslands, and habitat for game. But when Europeans arrived, they brought fear of fire with them.
RM: And over time, in much of the country, not only did we do away with the practice of setting fires, we actually started to extinguish naturally-occurring fires too. In 1911, that became an official responsibility of the newly-created Forest Service.
SJ: And in 1935, that policy even got a name: The 10 a.m. Rule. It said the Forest Service should put out every new fire on public land by 10 a.m. the following day. President Roosevelt’s Civilian Conservation Corps was on the frontlines of implementing that policy.
(Recording) We fought those fires, night and day, sometimes. Lots of days, especially in the spring, you could see smoke clear to the end of the world.
RM: The belief was that with enough water and manpower, firefighters could put out any wildfire. And a huge industry rose up around that idea. It grew to employ tens of thousands of people, with hundreds of millions of dollars a year being spent on planes and helicopters and fire crews.
SJ: And for a while, that brute-force approach seemed to work; but those early firefighters had an advantage. For millennia, before the rise of modern fire suppression, wildfires had burned regularly through America’s forests. They would eat up all the fuel. So when there were fires, they were often low-intensity and stayed on the forest floor.
RM: As firefighters began aggressively fighting fires, that balance started to change. With fewer fires burning, forests started to get more and more dense.
SJ: That meant when the forest did catch on fire, there was more material to burn; and the fires burned hotter and bigger.
RM: Effectively, by suppressing natural fires we created something that turned out to be much, much worse. Here’s Mark Finney, he’s a fire scientist with the Forest Service.
MARK FINNEY: Fighting fire really has some unintended consequences that may be even worse than the fire itself, and often are.
RM: Since the very beginnings of our fire suppression policies, there have been people arguing that it wasn’t a good idea to put out every fire. But it took until the 1980s for that idea to really take hold. By then, it was also becoming increasingly clear that we couldn’t put out every fire. Especially as they got bigger and bigger.
MF: We’re not actually stopping them. We’re just delaying them. You know there’s a saying a fire put out is a fire put off.
SJ: But even as the public in the 80s started to accept the idea that fire was natural and necessary, and fighting it had unintended consequences, not fighting it didn’t seem like a viable option outside of remote wilderness areas. Because how could you stop fighting fires when they threatened people’s homes?
RM: Which brings us back to Jack Cohen and the Panorama fire. Once he started to focus on the home as the problem, not the wildfire, he wanted to know what made some houses more susceptible than others.
JC: This was a question that I had in my mind, a curiosity question. What I’m trying to do is to establish a relationship between wildfire and home destruction. I want to know what that linkage is. How does this happen?
RM: In the Panorama fire, it had clearly been the wood roofs. But in other fires, there were plenty of homes without wood roofs that burned too.
SJ: So Jack set about learning all of a houses’ potential weaknesses; all the ways it might plausibly catch on fire. The first thing he wanted to know was how close the flames of a wildfire had to be to a house for it to ignite simply from the radiant heat.
RM: To answer that question, he did a series of experiments, including one in the late 1990s in northern Canada where he set an actual forest on fire.
SJ: So, you actually, like, cut plots into a forest…
JC: The boreal forest
SJ: and then set them on fire?
SJ: And watched them burn?
SJ: What Jack found in the experiment was that an entire forest could be on fire, 30 feet away from the house, and nothing. It was fine.
RM: But of course Jack knew that the flames and the radiant heat weren’t the only threats to the house. There were also the embers. He frequently found himself standing next to houses reduced to ash, and next to them: green trees. It was a telltale sign that the fire front never even reached the home, but the embers did.
SJ: Jack has a slideshow he likes to share with photos of burned houses. And it’s like the optical illusion with the vase and the faces. At first, you look at the aftermath of a wildfire, and all you see is the destruction. But after a few slides, suddenly the green trees shift into focus, and it’s easy to see that the home is often the only thing that’s burned.
JC: So I mean one of the things that I always try to point out because everybody that looks at news footage and pictures can readily observe no trees on fire and the structure burning.
SJ: So, he did experiments to see exactly how the embers were setting houses on fire. He discovered embers like to collect in lots of places, like in the corners of wood decks, and in gutters full of pine needles, and in attics with open vents.
RM: Since a lot of people evacuate during a wildfire, there’s no one around to douse the embers. They smolder and set fire to the entire house.
SJ: the more Jack thought about it, the more he came to believe that most ember fires could be stopped with some simple design solutions.
JC: I mean, you don’t have to live in a bunker; you don’t have to cut all your trees down.
RM: Jack began to develop guidelines for designing and landscaping homes to withstand a wildfire. He started by drawing a buffer, based on a conservative interpretation of those Canadian fire experiments. He called it the “Home Ignition Zone.”
JC: The home ignition zone is limited to the house and its immediate surroundings out to about a hundred feet.
SJ: Between 100 feet and 30 feet from the house, the goal is to space trees so that the fire can’t jump between them and is forced to the ground. Between 30 and 5 feet, the goal is to landscape and design so the groundfire loses steam, by removing fuels like tall grasses and woodpiles. And within 5 feet of the house, the goal is to stop the fire dead in its tracks, with things like rock beds and well-irrigated grass.
JC: What I’ve found is that you don’t have to be very exotic about your design and materials in order to make the houses very resistant to ignition.
RM: Jack also came up with a long list of suggestions for preventing ember fires on the house itself. From the big and obvious ones like replacing your flammable wood roof, to the smaller and less obvious, like making sure your garage door has a tight seal with the concrete and removing decorative juniper trees, which are extremely flammable.
SJ: Some of these ideas were pretty intuitive and had been floating around for a long time. In many fire-prone communities, homeowners had long been encouraged to clear flammable vegetation from their properties and to maintain their homes in ways that would reduce their chances of catching fire. But Jack’s experiments allowed him to put hard numbers to people’s intuitions and to develop specific, evidence-backed recommendations for the changes homeowners should make.
RM: And Jack’s experiments also showed that when those changes were made, a house was much less likely to burn. In fact, he showed that was the main factor in whether a house was going to burn. It wasn’t about the intensity of the wildfire or its size. It was really about what was happening within 100 feet of your home.
SJ: And that led him to a further, far more radical conclusion:
JC: You can have extreme wildfire behavior, not control that, and yet still have houses survive.
RM: In other words, we may not even need to fight fires, as long as buildings near fire-prone areas are designed to withstand them.
SJ: It wasn’t that there weren’t other reasons to fight fires, but Jack said there was no need to fight a fire if the only goal was to save houses. And that ruled out fighting a lot of forest fires.
JC: So we have the opportunity to separate the wildfire issues from the home destruction issues. We can separate those.
RM: Which meant we could let more forest fires burn naturally and finally break out of the vicious cycle of fire suppression that leads to the largest infernos.
RM: Jack thought he had come up with a way to save houses and let fires burn naturally, he thought it was a win-win. And so in 1999, he presented a paper about his findings at a fire conference in San Diego.
JC: So I give this paper in front of a group of mostly agency people.
RM: People with the Forest Service, and state fire agencies; people in a position to change policy.
SJ: And Jack says they are totally uninterested. Like, no questions. Jack is up there, saying that it’s really only what happens within a hundred feet of a home that determines whether it burns, and no one seems to care. Except this one guy, from an environmental group.
JC: And as I’m walking out he says, “Do you have a copy of that paper?
SJ: And Jack’s like, sure… here’s a copy. A few days later, a newspaper reporter calls, asking about Jack’s talk. Jack gives him an interview and the article comes out in the local paper.
JC: I don’t exactly remember the headline, but it was something like “Forest Service has its head up its ass.”
RM: That wasn’t the actual title of the article. But the story did imply that basically everything about how the Forest Service dealt with wildfires was wrong.
SJ: Because remember, the 10AM rule had left us with this huge fire fighting infrastructure. The Forest Service was spending hundreds of millions of dollars on planes and fire crews… and was approving massive logging projects on the grounds that thinning out the forest would help reduce the intensity of wildfires and save homes. And Jack was saying, actually, it would be way more effective if you just encouraged homeowners to maintain and retrofit their properties.
JC: Nine o’clock in the morning I get a phone call from Region 6 Forest Service. The Fire Director of regions 6 “What do you think you’re doing?”
SJ: Jack knew immediately that he was in trouble. The way he remembers the conversation, the director told Jack he was putting those big logging projects in jeopardy; and that put the director in a sticky political situation.
RM: But in the middle of getting chewed out by the director, Jack just doubled down. He says he knew what the data said, he knew the science wasn’t wrong. And he told the director the logging projects weren’t going to do much to save homes.
JC: And I said well you might have a problem. Because the research I’ve done doesn’t indicate that that’s going to be very effective. That was the end of the phone call and pretty much the beginning of adversity for the next three or four years at least.
SHAWNA LEGARZA: I don’t know, I wasn’t at a level to know why there was resistance.
SJ: This is Shawna Legarza. She’s currently the National Director of Fire and Aviation Management for the Forest Service. Back when Jack was first promoting his ideas, she wasn’t in management; and so she wouldn’t comment on the pushback that Jack says he faced.
RM: She does say that, over her thirty-year career in the Forest Service, she’s seen more and more emphasis placed on strategies like “defensible space” which means clearing your property of flammable materials. And she’s happy about that.
SL: I believe that, you know, people taking more ownership in their home and having defensible space is number one.
RM: But there’s only so much the Forest Service can do to encourage people to make changes. A lot of that work falls to local governments and individual homeowners. And even today, not everyone is convinced that it’s important to invest in the kinds of preparations that Jack recommends.
SHAWNA: Yeah. You know so it’s kind of scattered across the country. Some communities don’t believe a fire will ever happen where they’re at. It will never happen to me and I’ll never have to evacuate and so I want to keep my trees and shrubs right by my house. And unfortunately, time is telling us or showing us that it does happen. Fire has no boundaries and no preference for where it burns.
SJ: And in the meantime, the Forest Service has a congressionally-mandated duty to fight fires.
Last year, the federal government spent more than 2 billion dollars fighting fires and just a small fraction of that on prevention and mitigation efforts.
MF: We, our culture views fire as primarily an emergency response activity; but if you treat fire only as an emergency response under emergency circumstances, you’re missing out on all the preventative care you could do.
SJ: This is Mark Finney again. You’ll remember he also works for the Forest Service. And while he was on board with Jack’s ideas, he also understood that there were huge challenges to implementing them. There were reasons why they didn’t catch on at first.
MF: You can’t just throw a bunch of scientific papers on the table and have everybody read them and go, “Oh jeez thanks! That’s what I needed.” Now we have a different view of how things work. Whew.
RM: There’s too much history behind the idea that we’ve got to do something about fire… whether it’s effective or not. We, the public, expect to see the dramatic shots of airplanes flying over raging fires, dropping water on them. But when communities put the principles Jack articulated into practice, they work. There are several communities in Southern California built with wildfires in mind that have survived when nearby homes didn’t.
SJ: But those homes are mostly custom designs in gated communities. They have homeowners associations that enforce strict rules about vegetation clearing, and home design. Making changes elsewhere is more complicated. For starters, many homeowners may not even have 100 feet of space to clear and fireproof. It’s expensive to replace your roof. For renters, they may not have the authority to make changes to their homes. And in many cases, there aren’t incentives for people to invest.
RM: Plus, many homeowners just kind of instinctively get that the odds of being in a wildfire are extremely low. There are more than 40 million homes in wildfire-prone areas, and only a few thousand burn every year. Without someone compelling them to do it, homeowners might decide it’s just not worth spending time and money to change their properties.
SJ: So even though Jack’s ideas are pretty simple, they’re not simple to actually implement in the real world. Jack tells this story about a friend of his who said that modifying homes to make them fire-resistant isn’t “rocket science.”
JC: And I said to him, “No this is much harder. This is social science. And his comment is, “Oh geez we’re screwed!”
RM: Jack’s ideas have become more mainstream over time. Fire agencies like the Forest Service now talk a lot about defensible space. There’s more emphasis placed on homeowner responsibility. Jack also helped start the prominent organization FireWise, which promotes fire preparedness.
SJ: Shawna Legarza, the Forest Service fire director, says that the enormously destructive fires of the last few years have also forced people to think about how to make their homes and properties more fire-resistant.
SL: And I think every year there’s going to be more awareness about wildland firefighting and evacuations and do you have defensible space or not, just because of the trends every year. You know we thought last year was the largest and most devastating fire year. And now we have this year which is larger and more devastating than last year, human fatalities, firefighter fatalities.
SJ: And with climate change, the fire season is only getting longer. So when I asked Legarza if she could imagine a future like the one Jack proposes, where the Forest Service would get out of the fire fighting business?
SL: Boy, I think we’re a long ways from that. You know, I mean, we’re all aboard for fire-adapted communities and resilient landscapes and for you know, folks to have a defensible space around their structures, and more healthy resilient national forest systems land. We’re a long ways from that, we are a long ways from that.
RM: The Forest Service is currently fighting several dozen fires across the western United States. When you’re that busy running around putting out fires, literally; it’s hard to focus on how to prevent them from being so destructive in the first place.
SJ: Jack retired from the Forest Service a few years ago, feeling like all his research hasn’t made much of a difference in the end. When he’s watching the news, especially coverage of the past few destructive fire seasons in California, he’s noticed there isn’t a lot of talk about making homes more fire-resistant or clearing defensible space. Instead, there’s a lot about firefighting.
The fire swept down the valley with apocalyptic fury…
Overwhelmed firefighters did what they could.
Overnight, the battle against the giant infernos intensifying
When that wind was blowing, there’s not much you can do
FIREFIGHTER: There’s no way you can stop a fire front like that.
JC: One of the very frustrating things that I had experienced this past summer particularly from the California fires, is the continued sense of fatalism. “Oh well, there’s nothing that could be done.” Well no, the bottom line is that we can do something, it just doesn’t have anything to do with controlling the wildfire.
SJ: Watching news footage from those California fires, something stands out, especially if you’ve spent a lot of time with Jack. Once you get over the shock of seeing neighborhoods reduced to ashes, and the drama of firefighters talking about how there was nothing they could do to stop the flames, your eyes shift to something else: the green trees, untouched by fire, surrounding the burned out homes.