Trees grow thicker bark and animals burrow for protection. We can use similar techniques to save human lives
California wildfires rarely killed civilians in the 20th century. The Griffith Park fire killed 29 in 1933, while 25 died in Oakland in 1991. Now, for the fourth time in just over a year, California wildfires have become deadly. Within the span of 13 months, nearly 100 civilians have died in wildfires in California, and that devastating number is likely to grow based on the missing persons tally from the town of Paradise.
The increasing number of fatalities is occurring globally in so-called Mediterranean climates – regions with mild, wet winters and warm, dry summers. Portugal, Spain, Greece, Chile, Australia and South Africa have all seen civilian wildfire fatalities in recent years, and communities globally are asking themselves the same question: what can we do? How do we stem the soaring number of wildfire fatalities?
As fire scientists, we argue that communities should look to the natural world to help identify ways to make our homes more resilient to wildfire.
The natural world has developed ways of surviving and using wildfires that we humans can adopt
Fire science is very good at understanding the mechanics of the problem: some combination of climate change, population expansion and problematic land management creates a scenario where explosive wildfires become more frequent and deadly. But what we haven’t gotten very good at is identifying solutions that specifically stop people from dying and houses from burning. It’s hard to do, because we can’t create controlled scientific experiments that replicate what wildfires do. What we can do, however, is look at success stories: places where wildfires were expected to be disastrous but weren’t.
Montecito, California, was in the path of last December’s Thomas fire. The community sits just east of the city of Santa Barbara and is home to celebrities and many large estates. For the past 20 years, the Montecito fire protection district has been working with residents to reduce their fire risk by creating defensible space around homes, hardening structures with less flammable building materials, removing vegetation next to major roads, creating “fuel breaks” of reduced vegetation in critical areas, widening lanes and driveways, and developing detailed plans for what they would do if a wildfire did occur.
When the Thomas fire roared into Montecito, it was during the worst conditions imaginable. Strong, offshore winds, similar to those wreaking havoc on the current wildfires, created extreme fire behavior and huge ember showers. Flaming palm fronds blew everywhere. Heavy smoke blanketed the community, and no aircraft could be used to support firefighters due to the winds.
Firefighters were worried they would lose hundreds of homes, and potentially even lives. But when the smoke cleared, only seven homes had been lost, each for a seemingly random reason. More importantly, no one was killed or injured.
It was a major success for firefighters. But the preparations also paid off and point to strategies other communities can adopt to reduce the risks posed by wildfire.
What the residents of Montecito may not have realized is that they were effectively copying nature on how to live with fire, a strategy known as biomimicry. Some trees have evolved to grow thick bark that serves as armor against the heat of fires. Like these trees, residents used stucco and fiber cement siding, Spanish tiles for roofing, and other less flammable building materials. They placed ember screens over vents and made their houses less susceptible to embers, essentially filling the “chinks” in the armor.
In fire-adapted forests, trees are also relatively well-spaced, such that if one plant catches fire, the flames can’t easily spread to neighbors. The residents of Montecito, particularly those along the edge of the wildlands, adopted this principle by creating defensible space around their homes, removing and converting the highly flammable native shrubs to grass or well-irrigated orchards. Communities everywhere can reduce the risk of fire spreading by removing or replacing what connects our houses – flammable yard furniture, landscaping vegetation and bark, and even wooden fences. Selecting yard plants that have evolved to smolder (eg succulents) and not produce many embers would be a smart strategy. Across much of the west, some of the plants most frequently chosen for xeriscaping (eg juniper, palm, and cypress trees) are among the most flammable and potentially deadly for homeowners.
The natural world has developed many more ways of surviving and using wildfires that we humans can adopt. Some plants hide all of their most valuable resources underground in their roots, allowing them to regrow quickly after fire. Many animals burrow underground to hide from the flames and birds can fly high and away from danger. Humans could bury power lines (which start many of the wind-driven wildfires) and build underground structures to shelter in place. We already install such shelters in tornado-prone areas of the midwest, where root cellars once saved homesteaders from both fire and funnels.
Calls for restricting new construction in fire-prone areas are unrealistic – in the US, we build on earthquake faults, in tsunami zones, in tornado alleys and on coastlines pummeled by hurricanes. Besides, California harbors some of the most expensive real estate in the country, and restricting growth will only serve to further marginalize the poorest and most vulnerable among us, who already suffer the worst impacts of natural disasters.
What we can do is build smarter and with wildfire in mind. The Dutch have learned to live with floods rather than fight them. In the US, we need to expect and prepare for fire, rather than relying on firefighters to stop it. Otherwise, we will continue to see our lives go up in smoke.
Alistair Smith is a professor of wildland fire science and Crystal Kolden is an associate professor of pyrogeography in the College of Natural Resources at the University of Idaho