Backburning: fighting fire with fire

This fire suppression tactic helped to keep the Sequoia National Park headquarters safe during the KNP Complex fire

Two firegfighters stand on a ridge with fire and smoke
Backburning on Ash Mountain during the KNP Complex fire. Photo credit: Saul Tejeda, Rilee Nilson

Sometimes fire crews use fire to “fight” fire. This is called backburning. Instead of allowing fire with unpredictable behavior to reach areas of high concern (such as residences and giant sequoia groves) at high severity, crews add fire to the ground to influence the fire to burn under preferable conditions. 

A firefighter stands next to fire burning on a ridge
Backburning on the KNP Complex fire. Photo credit: Saul Tejeda, Rilee Nilson

Fire burns where there is available fuel. If the conditions are right to put fire on the ground, crews can burn the fuel ahead of the fire and slow it down significantly. Oftentimes backburning happens at night when temperatures drop, winds calm down, and humidity rises. This helps prevent fire from reaching an area during the peak burn period during the day when it’s hotter and drier and winds are gustier. 

Firefighters working on a fire on a mountain at night
Fire crews have been working around the clock to contain the KNP Complex fire. Photo credit: Saul Tejeda, Rilee Nilson

Here’s an example of back burning: In the KNP Complex, fire was quickly approaching a ridge close to Ash Mountain, adjacent to the headquarters of Sequoia National Park. Fire gains intensity as it moves up steep slopes. So, to prevent the fire from running up the slope and gaining intensity, crews cut a handline on the ridge and put fire on the ground to the east of that handline. This helped to protect important park infrastructure for the time being. 

Firefighters on a ridge with a handline along a ridge with fire and smoke
Fire crews set handlines on the ridge to backburn the area. Photo credit: Saul Tejeda, Rilee Nilson

 Backburning is more common than some people might think; it is often how crews protect structures, homes, communities, or other values at risk. In addition to prescribed burning and cultural burning by Indigenous peoples, this is yet another case in which fire can help protect our lands and people. Fire crews are not only brave, but also extremely skilled. We at the League are so grateful for their work and expertise. 

A helicopter drops pink fire retardant on a mountain as two firefighters stand below
Firefighters working on the KNP Complex fire. Photo credit: Saul Tejeda, Rilee Nilson

About the author

Linnea Hardlund is a former field botanist, a wildland firefighter, and a fire ecologist. She is now the League's Forest Ecologist. She is named after her great grandmother and Swedish botanist Carl Linnaeus.

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