Heavy, dark clouds roll over the forest hillside. Lack of rainfall and high temperatures have created near-perfect conditions for a wildfire to ignite. In a flash, a bolt of lightning splits a tree into splinters, erupting into flames.
That is how most people think wildfires start. The truth is only around 20% are ignited by lightning. The more common causes of ignition are far more preventable because they are human.
Statistics show that people cause anywhere between 85% to 97% of all reported wildfires. In 2020, lightning ignited 5,300 fires while people were responsible for 53,000 fires. Together those fires burned 10 million acres, damaged or destroyed 17,000 structures (including 9,000 homes), according to the National Interagency Fire Center.
“When we refer to human-caused fires, we are talking about everything but lightning,” said Jeff Prestemon, a senior research forester with the Forest Service’s Southern Research Station. Although some of those human causes are from industry such as sparks from powerlines or railcars, individuals also have a role to play in preventing many of the wildfires we see in our national forests.
National forests and grasslands receive around 150 million visitors a year. Friends and families come to enjoy the great outdoors in variety of ways.
“Some of those activities carry more fire risk than others, such as cooking and campfires, shooting sports, and riding off-highway vehicles,” said Prestemon, who has studied economic and fire related topics for more than 20 years.
“If a person is conscientious, these risks can be easily mitigated. If you are going to start a campfire ensure that there is bare space around the fire and that it is properly contained. Have a shovel or an extinguishing source ready just in case,” Prestemon said. “And before leaving the fire, be sure to put it out thoroughly. If riding a dirt bike or ATV, have a spark arrestor that will stop sparks from exiting the muffler and potentially starting a fire in finer grasses.”
Another often cited cause of wildfires is juveniles or children playing with fire, said Prestemon. “Parents should watch their kids closely, they don’t have the reasoning skills of an adult and are less likely to realize when using fire might be risky.”
Awareness is an important part of preventing wildfires. People heading out to their public lands should be aware of that day’s Fire Danger Rating which indicates the potential for a fire to ignite, spread, and require action from wildland firefighters.
The Fire Danger Rating is calculated by measuring the dryness of wood, grass and other combustible material, weather conditions, and the terrain. The combination of these factors results in one of five fire danger levels: low, moderate, high, very high, and extreme. Low means that it will take a more intense heat source to ignite a fire and also that any resulting fire would spread slowly and would be easier to contain, this could be due to wet weather, or a high level of moisture in woods and grasses.
On the other end of the spectrum, when the Fire Danger Rating is set to extreme, weather is hot, dry and/or windy. While these conditions persist fires are easily ignited, burn intensely, spread quickly, and are difficult to control.
“The good news is that wildfire education works, and making the public aware of the many causes of wildfires and how to prevent them reduces the number of fires,” said Prestemon. “Be aware of fire risk related to the activity you're engaging in and of the day’s Fire Danger Rating. Help us prevent wildfires. Don’t let your fun turn to flames.”