BEHIND THE SCENES: Fire engineers at the Insurance Institute for Business & Home Safety’s fire testing facility stand behind protective glass as they record a house burning in their lab in South Carolina.

RYAN KELLMAN/NPR

STANDARDS

NGSS: Core Idea: ESS3.B

TEKS: 6.5C, 7.8A, 8.3D, E.5A, E.8A, E.9E

# Studying Infernos!

Scientists re-create wildfires in labs to discover what makes them so dangerous and destructive

AS YOU READ, THINK ABOUT why scientists might choose to study wildfires in a laboratory setting rather than in real life.

A gust of wind picks up glowing hot embers, showering them on a lawn just a few feet from a home. The sparks ignite the dry grass. Within minutes, huge flames begin to lick up the sides of the house. It’s not long before fire engulfs the entire structure. Thankfully, no one is inside the building. That’s because this isn’t a real house—it’s a model home constructed inside a research lab and purposefully set on fire.

The Insurance Institute for Business & Home Safety (IBHS) operates the research facility in South Carolina. The nonprofit organization studies different threats to people and property, like wildfires. This type of research is more important now than ever, as wildfires become more severe, frequent, and widespread in many places across the western and southwestern U.S. (see Feeling the Burn).

A gust of wind picks up glowing hot embers. It drops them on a lawn just a few feet from a home. The sparks ignite the dry grass. Within minutes, huge flames lick up the sides of the house. Soon the fire consumes the whole building. Thankfully, no one is inside. This isn’t a real house. It’s a model home built inside a research lab, and it’s set on fire on purpose.

This research facility is in South Carolina. The Insurance Institute for Business & Home Safety (IBHS) runs it. The nonprofit organization studies different dangers to people and property, like wildfires. This type of research is more important now than ever. That’s because wildfires are becoming more severe, common, and widespread in many places across the western and southwestern U.S. (see Feeling the Burn).

LIDO VIZZUTTI/THE NEW YORK TIMES/REDUX (CHAMBER); RYAN KELLMAN/NPR (HOUSE)

• FLAME CHAMBER: Mark Finney and a colleague study how fire behaves in their lab in Montana (left).
• TWO-SIDED HOUSE: The right side of this model home was constructed from fire-resistant materials; the left side was made of flammable materials. Scientists compared how each side burned in a lab (right).

Last year’s wildfire season in California was devastating. The Camp Fire that destroyed much of the town of Paradise in Northern California killed 86 people and was the costliest wildfire in state history. More than 18,500 buildings were destroyed, and damages totaled $16.5 billion. By simulating wildfires in a controlled environment, researchers can safely investigate how the blazes ignite and spread in the real world. They can learn how human behavior might be contributing to the increasing intensity and number of wildfires and find ways to combat the blazes. Most important, what researchers learn in the lab could help those in the path of a fire survive real-life disasters. Last year’s wildfire season in California was crushing. The Camp Fire destroyed much of the town of Paradise in Northern California. It killed 86 people and was the costliest wildfire in state history. More than 18,500 buildings were destroyed, and damages reached$16.5 billion.

When researchers simulate wildfires in a controlled setting, they can study them safely. They learn how the fires ignite and spread in the real world. The number and strength of wildfires is growing. Researchers can learn how human actions might be helping to cause this. And they can find ways to fight the blazes. But their findings in the lab have an even more important effect. They could help people survive real-life wildfires.

## SAFER SHELTERS

Inside the IBHS testing facility, 105 powerful fans mimic wind, indoor sprinklers simulate rain, and a system creates and propels hot embers. Researchers use these devices to see how building materials hold up during natural disaster scenarios like wildfires, hurricanes, hailstorms, and high winds.

“One of the challenges of studying natural perils is that it’s not safe for people to be there when they’re happening,” says Daniel Gorham. He’s a former firefighter who now works as a fire engineer at IBHS, designing wildfire simulations.

Inside the IBHS testing facility, 105 powerful fans imitate wind. Indoor sprinklers simulate rain. Another system creates and shoots out hot embers. These devices simulate natural disasters like wildfires, hurricanes, hailstorms, and high winds. Then researchers can see how building materials hold up under these conditions.

“One of the challenges of studying natural perils is that it’s not safe for people to be there when they’re happening,” says Daniel Gorham. He’s a former firefighter. Now he designs wildfire simulations as a fire engineer at IBHS.

JUSTIN SULLIVAN/GETTY IMAGES

BATTLING AN INFERNO: A firefighter combats the Camp Fire in Northern California in November 2018.

During a recent test, IBHS built an entire model home, half constructed with fire-resistant materials. The other half was made with commonly used building materials, like wood siding, that can catch fire. Within minutes of researchers blowing fiery embers toward the house, the flammable half was an inferno, while the noncombustible half was unaffected. Flames from a wildfire aren’t usually what ignite homes, says Gorham. The most common culprits are tiny embers from burning debris carried by the wind over long distances.

Tests like this one have helped IBHS identify materials and practices to better protect homes from wildfires. For example, homeowners can install synthetic wood siding that won’t catch fire and also swap flammable wood mulch for gravel in flowerbeds (see Safe From Flames). For people living in regions where wildfires are common, Gorham explains, implementing these changes can be the key to saving their homes—and their lives.

For a recent test, IBHS built an entire model home. Half was made with fire-resistant materials. The other half was made with common building materials, like wood siding. These can easily catch fire. Then researchers blew burning embers toward the house. Within minutes, the flammable half was swallowed by flames. But the fire-resistant half wasn’t affected. Flames from a wildfire don’t usually ignite homes, says Gorham. Tiny embers from burning material usually do. These are carried by the wind over long distances.

IBHS wants to find materials and practices that better protect homes from catching fire. Tests like this one have helped. For example, homeowners can use imitation wood siding that won’t catch fire. And they can use gravel in flowerbeds, instead of flammable wood mulch (see Safe From Flames). These changes are important for people in places where wildfires are common, Gorham explains. They can be the key to saving their homes—and their lives.

## RECIPE FOR DISASTER

At the U.S. Forest Service’s Missoula Fire Sciences Laboratory in Montana, Mark Finney also creates indoor blazes. Finney, a research forester, aims to better understand the factors that influence wildfires and how they spread. “Nature has a recipe for wildfires,” says Finney. It requires just three ingredients: fuel, heat, and oxygen (see What Causes a Blaze?).

To understand how these components interact to create large, out-of-control fires, Finney’s team uses a burn chamber. The fireproof room allows them to safely study fires by adjusting conditions like temperature, humidity, and wind speed. Finney explains that researchers would not be able to learn as much just by observing fires in nature. “The problem is that you can’t control or know exactly what’s influencing the fire [in the field],” says Finney.

Mark Finney also creates indoor blazes. He works at the U.S. Forest Service’s Missoula Fire Sciences Laboratory in Montana. Finney is a research forester. He wants to better understand wildfires and how they spread. “Nature has a recipe for wildfires,” says Finney. It takes just three ingredients: fuel, heat, and oxygen (see What Causes a Blaze?).

These ingredients work together to create large, out-of-control fires. To understand how, Finney’s team uses a burn chamber. The fireproof room allows them to safely study fires. They can change conditions like temperature, humidity, and wind speed. Researchers couldn’t learn as much just by watching fires in nature, Finney explains. “The problem is that you can’t control or know exactly what’s influencing the fire [in the field],” he says.

## FOCUS ON FLAMES

One factor Finney’s team is interested in studying is how flames spread along a fuel bed—a layer of flammable material used in wildfire simulations. The scientists monitor the simulated blaze using video cameras and sensors that detect temperature changes and gases produced. In the past, researchers would create fuel beds with natural materials like pine needles, twigs, wood chips, and blocks of wood. But natural materials can vary a lot. For instance, pine needles can differ in how moist or dry they are. These differences make it difficult to replicate results and compare observations between experiments. That led Finney to search for materials that would allow him to create similar fires over and over.

“We considered a number of options: paper, matchsticks, Popsicle sticks,” says Finney. “But none of them worked well, and constructing a fuel bed from them was labor intensive.” So Finney turned to a machine called a laser cutter to cut cardboard into what looks like the equally spaced teeth on a comb. The uniformity ensures that a fire spreads consistently along the fuel bed. Being able to watch a fire spread from one identical cardboard prong to another made it easier for Finney’s team to draw conclusions about the nature of wildfires—and revealed clues about how to fight them.

Finney’s team is studying different factors. One is how flames spread along a fuel bed. This layer of flammable material is used in wildfire simulations. Video cameras allow scientists to watch the simulated blaze. Sensors detect temperature changes and gases produced. In the past, researchers would create fuel beds with natural materials. They used pine needles, twigs, wood chips, and blocks of wood. But natural materials aren’t always the same. For example, pine needles can be wetter or drier. These differences make it hard to get the same results and compare experiments. So Finney searched for materials that would result in similar fires over and over.

“We considered a number of options: paper, matchsticks, Popsicle sticks,” says Finney. “But none of them worked well, and constructing a fuel bed from them was labor intensive.” So Finney cut cardboard with a machine called a laser cutter. The cut cardboard looks like the evenly spaced teeth on a comb. Because of the even spaces, a fire spreads the same way along the fuel bed. Finney’s team could watch a fire spread from one cardboard tooth to another just like it. That made it easier for them to learn about the nature of wildfires. And it revealed clues about how to fight them.

Flames rise and fall in a wave-like pattern across the top of a fire. This phenomenon occurs as hot air rises and cooler air sinks to take its place. Researchers had assumed that taller flames produced during a wildfire helped it spread, suggesting that firefighters should try to extinguish such flames first. But by observing the burning cardboard in the lab, Finney concluded that firefighters were focusing on the wrong places. Sinking cold air forces superheated gases—created when materials combust—downward. These gases push outward from the fire, igniting new fuel, like pine needles and grass along the ground. The key to stopping a fire really lies in preventing the blaze from spreading in the low areas between large flames.

Flames rise and fall like waves across the top of a fire. This happens as hot air rises and cooler air sinks to take its place. Researchers had thought that taller flames helped a wildfire spread. This suggested that firefighters should try to put out such flames first. But then Finney watched the burning cardboard in the lab. He concluded that firefighters were focusing on the wrong places. Superheated gases form when materials catch fire. Sinking cold air pushes these gases downward and outward from the fire. This ignites new fuel, like pine needles and grass along the ground. Finney saw the real key to stopping a fire. It’s keeping the blaze from spreading in the low areas between large flames.

## CHANGING CONDITIONS

Understanding how a fire ignites new fuel sources could allow firefighters to better target areas to halt its movement. However, while Finney’s discovery might help suppress an active wildfire, it won’t prevent more of these disasters from starting in the first place.

If firefighters understand how a fire ignites new fuel sources, this could help them. They could target the best areas to stop its movement. Finney’s discovery might help stop an active wildfire. But it won’t keep more wildfires from starting in the first place.

RICHARD BARNES/THE NEW YORK TIMES; LIDO VIZZUTTI/THE NEW YORK TIMES/REDUX (INSET)

FIRE TEST: A fuel bed made of identical cardboard prongs helps researchers study the behavior of flames.

The reason wildfires will likely continue to worsen has a lot to do with the way people have altered the landscape and environment, says John Abatzoglou (uh-BAHTZ-uh-gloo). He’s a climatologist at the University of Idaho who studies how a changing climate is affecting the western U.S. “It’s difficult to contain fires when we have dry fuels and strong winds,” says Abatzoglou. “And we’re seeing more of those conditions in the U.S. over the past half century.”

Because people stop most fires, large amounts of dead and dried vegetation accumulates on forest floors. Droughts and warmer temperatures caused by climate change lead more vegetation to dry out. That creates even more fuel for future fires, particularly in the western parts of the U.S. Unusually strong winds, like those that whipped up during last year’s wildfire season in California, can then fan the flames.

Wildfires will likely keep getting worse.  The reason has a lot to do with the way people have changed the landscape and environment, says John Abatzoglou (uh-BAHTZ-uh-gloo). He’s a climatologist at the University of Idaho, and he studies how a changing climate is affecting the western U.S. “It’s difficult to contain fires when we have dry fuels and strong winds,” says Abatzoglou. “And we’re seeing more of those conditions in the U.S. over the past half century.”

People stop most fires, so large amounts of dead and dried vegetation pile up on forest floors. Climate change causes droughts and warmer temperatures. As a result, more vegetation dries out. That creates even more fuel for future fires, especially in the western U.S. And unusually strong winds can fan the flames. That’s what happened during last year’s wildfire season in California.

DAVIN G PHOTOGRAPHY/GETTY IMAGES

CONTROLLED FIRE: A firefighter starts a prescribed burn to remove dead, dried vegetation before it can ignite and start a wildfire.

A typical wildfire season in California begins in midsummer and ends in early fall with the arrival of rain across the region. The last couple of years, though, have seen a late arrival of rains. As a result, fire season has extended into late fall and winter, says