There are more big, fast-moving, damaging wildfires in the United States because of a plant that is easy to find, tough, and doesn’t seem to be harmful. The grass is as common as the sun, and when the weather is right, it’s like gasoline for wildfires—all it takes is a spark to set it off.
Temperature and rainfall are getting worse because of pollution that warms the planet, which is making fires bigger and more common. The fires are making the damage to the environment worse, which is helping grass become king. Adam Mahood, a study ecologist with the US Department of Agriculture’s research service, said, “Name a place and there’s a grass that can live there.” “There will be some kind of grass on any 10-foot area that isn’t gravel.”
Fire experts told CNN that grass fires usually start less quickly and don’t last as long as forest fires. However, they can spread much more quickly, get away from firefighters, and burn into the homes that are being built closer to wildlands that are more likely to catch on fire.
A new study shows that as fires get bigger and worse, the number of homes lost by wildfires in the US has more than doubled in the last 30 years. People didn’t start most of those fires in forests; they started in grass and bushes. This is because more than two-thirds of the homes that have burned down in the last 30 years have been in the West. Sod and grass fires destroyed almost 80% of those.
People are building in the so-called “wildland-urban interface,” which is close to wildlands that are prone to fire. From the 1990s to now, the amount of land burning in this sensitive area has grown by a huge amount. The number of homes has also gone up. The same study found that there were about 44 million homes in the interface by 2020, which is 46% more than there were 30 years before.
It’s clear that building in places that are more likely to catch fire is dangerous, but people also start most fires, so it also raises the chance that a fire will start in the first place.
In the parts of Kansas and Colorado that Bill King controls that don’t have many people, more than 80,000 homes are in the area where wildlands and cities meet. The US Forest Service worker said that people who live close to nature need to take action to keep damage from happening.
King said that property owners “need to do their part too” because these fires can spread miles away even if there is a big fuel break. This is because the fires get so big, intense, and sometimes driven by the wind.
A Great Chance For Wildfires
The western half of the US is under attack from all sides by fires caused by climate change. John Abatzoglou, a climate professor at the University of California, Merced, said, “The places that burn the most are the ones that get average amounts of rain.” “It’s kind of like Goldilocks.” “Just right, not too wet or too dry, with lots of sparks.”
In the Plains, which are in the middle of America and are usually dry and windy, a series of extremes that happen at different times of the year are making perennial plants perfect for setting on fire. There is more grass here than in other parts of the US, which means that fires can keep feeding on it. There are more megafires in the area, like the Smokehouse Creek Fire in Texas, and more deadly ones, like the Marshall Fire in Colorado in 2021, which destroyed more than 1,000 homes.
When it rains in the spring, more grass grows. After that, it sleeps, or “plays dead,” all winter. It gets warmer and drier in late winter and early spring when there is less snow cover in the Northern Plains and warmer winters elsewhere. This is what King and Todd Lindley, a fire weather expert for the National Weather Service in Norman, Oklahoma, say.
Lindley said that grass is especially dangerous because it changes with the weather. If it’s warm and dry for a short time, grass can catch fire faster than in woods. It only takes an hour or even a day after it rains for plants to lose water. A grass fire can be very dangerous if there is a spark, strong winds, and invasive plants that burn hotter and longer.
“If you get the right sequence of these multiple extremes that happen one after the other, it can be game on for this kind of wildfire,” Abatzoglou said. „Basically, you’re making it easy for the fire to spread there.”
Grass Growth
King said that extreme drought and years of not taking care of woods are making fires in western forests bigger and hotter. “When I first started, a big fire was 30,000 acres, and now that’s just small stuff,” King said. “I’d have one that big maybe once a year or twice a year, but now we hear about 100,000-acre forest fires.”
Grass grows in forests too, and it acts like a fuse to connect finer fuels that are easier to light to bigger tree systems that are suffering from drought, starting and spreading stronger fires. Grass grows where the trees used to be. Grass grows back much faster than other plants after a fire, and it can sometimes burn again in just a few months. King has seen this for himself.
“It grows back so quickly that you could see green grass growing in burned-grass areas in just one or two days,” King said.”Recovering forests could take years or generations, or they might not recover at all in our lifetimes or the lifetimes of our children and grandchildren.”
Native and non-native grasses are taking the place of more burned plants in the West. In the desert, Mahood of the USDA said, it’s making fires where there weren’t any before. Because annual grasses don’t grow all year like perennial grasses do in the Plains, the same drought-driven fires are getting bigger in deserts.
When it rains, these plants grow quickly and then die, leaving a carpet of fuel for fire on the desert floor. Mahood said that two recent fires in California’s Mojave National Preserve are great examples. Those fires burned hundreds of thousands of acres of Mojave Desert and more than a million famous Joshua Trees because of red brome grass that spread quickly.
Then, as it gets hotter and drier, native plants can’t rebound. There is more grass now. The famous, short sagebrush of the West is the largest ecosystem in the Lower 48 states. However, in the last 20 years, half of it has been lost or damaged. A USGS study found that every year grass, fire, and other factors destroy an area of sagebrush about the size of Delaware.
Because there is more grass and a lot of different climate factors, there is a higher chance of fires now and in the future. Mahood said, “Right now it may seem bad, but in ten years it won’t seem nearly as bad.” “Twenty years ago, fire season was terrible. Now, that seems like nothing.”
