The United States is facing an increasing wildfire threat, driven by a seemingly innocuous but ubiquitous culprit: grass. While often considered harmless, grass is proving to be a powerful accelerant for fast-moving and destructive wildfires. Experts warn that this risk is escalating due to climate change and shifting environmental conditions.
The Hidden Danger of Grass
Grass is as common as sunlight, thriving in nearly every environment across the US. Under dry and windy conditions, it acts like a natural accelerant for wildfires. According to Adam Mahood, a research ecologist with the US Department of Agriculture, grass can survive almost anywhere. “Any 10-foot area that’s not paved is going to have some kind of grass on it,” he said.
Unlike forest fires, grass fires tend to burn less intensely but spread much faster, often outpacing firefighting resources. This rapid spread is putting millions of homes in fire-prone areas at risk. A recent study found that most of the homes destroyed by wildfires in the past three decades were consumed not by forest fires but by fast-moving grass and shrub fires.
Wildland-Urban Interface at Risk
The growing number of homes being built near fire-prone wildlands is exacerbating the situation. More than 44 million homes are now located in the wildland-urban interface (WUI), where the risks of both igniting and being consumed by fire are high. Bill King, a US Forest Service officer, emphasized that living in these areas requires vigilance. “Property owners need to do their part too,” King said, “because these fires get so big and intense, they can spot miles ahead even with large fuel breaks.”
Climate Change’s Role in Worsening Fire Risk
Climate change is amplifying the wildfire threat across the western US. The combination of rising temperatures, shifting precipitation patterns, and windy conditions is creating the perfect environment for wildfires. As John Abatzoglou, a climate professor at the University of California, Merced, explained, “Globally, the places that burn the most are those with intermediate precipitation. It’s a little bit like Goldilocks—conditions have to be just right, with plenty of ignition sources.”
In the US Plains, where grasslands are more extensive, warmer winters and less snow cover are leaving grasses exposed to drying spells earlier in the year. This results in grass acting as an abundant, easily ignited fuel, ready to spark when conditions align.
Record-Breaking Fires
As climate change continues to fuel extreme weather, wildfires in the US are becoming larger and more intense. Fires like Texas’ Smokehouse Creek Fire and Colorado’s Marshall Fire, which destroyed over 1,000 homes in 2021, highlight the growing risk. Rainy springs lead to increased grass growth, which then dries out in the summer and winter months, creating a tinderbox environment ripe for disaster.
Grass is uniquely flammable due to its sensitivity to weather. It can dry out in a matter of hours and become fuel for a wildfire just a day after rainfall. The presence of invasive shrubs, which burn hotter and longer than native plants, only adds to the fire risk.
Grass Taking Over Fire-Scarred Landscapes
Grass is not only fueling fires but also rapidly reclaiming fire-scarred landscapes. When forests burn, grass moves in, creating a cycle that increases the likelihood of more intense fires in the future. “You could have green grasses coming up in a burned-grass landscape within a day or two,” King said. “Forest recovery could take years or generations, or never recover in our lifetime.”
The problem is not confined to the forests. In deserts, annual grasses are spreading after periods of drought, creating new fire risks where they didn’t previously exist. Two recent fires in California’s Mojave Desert, fueled by invasive red brome grass, burned hundreds of thousands of acres and destroyed iconic Joshua trees.
A Growing Crisis
The West’s native ecosystems are under siege by these invasive grasses. Sagebrush, which dominates much of the western US, has been severely degraded, with nearly half lost to grass and fire in the past 20 years. A study by the US Geological Survey found that an area the size of Delaware succumbs to these threats every year.
The wildfire situation in the US is dire, and it’s likely to worsen in the coming years. As Mahood warns, “It may seem bad now, but this will probably not seem nearly as bad in the next decade. Think about how bad the fire season was two decades ago—now, that seems like nothing.”
Conclusion
As climate change continues to wreak havoc on ecosystems and exacerbate fire risks, the spread of grass is creating a new and growing wildfire threat across the United States. With more homes being built in fire-prone areas and grasslands becoming more prevalent, the risk of devastating wildfires will only increase, leaving both people and the environment in a precarious situation.
