People cause the majority of wildfires

New research finds illegal campfires, cigarette butts and other accidental ignitions have nearly tripled the wildfire season.

 

Over three months in 2016, the Soberanes fire burned 132,127 acres of central California’s coast, blazing through dry swaths of dense chaparral, mixed hardwood timber and redwoods. Costing $260 million to suppress, it became the most expensive fire in the country’s history. And it wasn’t caused by lightning, which is relatively scarce in that part of the country, but by an illegal campfire in Garrapata State Park.

Human-caused climate change has meant more, and bigger, wildfires throughout the country. But as astute pyrologist Bruce Springsteen once wrote, “You can’t start a fire without a spark.” According to new wildfire research, the source of that spark is, more often than not, a person. What’s more, due to these human-caused ignitions, the country’s conflagrations have grown significantly larger and more frequent, while the overall fire season has tripled in length.

Firefighters work to contain the Soberanes Fire in California, which was started by an illegal campfire.
USFS

Jennifer Balch, assistant professor of geography at the University of Colorado-Boulder, quantified just how significant humans’ role in providing that spark is. Balch and her colleagues investigated federal, state and local records provided by the Forest Service of wildfires on public and private lands from 1992 to 2012. They determined that 84 percent of the 1.5 million wildfires that burned nationally over those two decades were lit by humans, not including controlled burns intentionally lit for fire management. In total, humans started more than 1.2 million fires.

Even in parts of the country where lightning strikes cause the most fires — such as the Intermountain West — humans have increased the number, size and length of the season for wildfires overall.

By mapping the Forest Service data, Balch’s team found that fires primarily ignite in areas of human-wildland interface: roads, urban encroachment into wild spaces and the edges of agricultural fields. Areas of high human population density and fewer lightning-caused fires experience more wildfires overall. These include central and southern California, where lightning is dry but rare, and the East Coast, where lightning is common but often accompanied by fuel-soaking storms.

And in urbanizing areas of the Intermountain West, human-ignited wildfires are increasing. This pattern can be seen along Colorado’s Front Range, where human-caused wildfires cluster where people have moved into wildlands near cities such as Fort Collins, Boulder, Denver and Colorado Springs.

Wildfires are larger and more common in areas of greater human density. This pattern is clear in coastal regions. New research shows that it’s true in urbanizing regions of the West as well.
Bethany Bradley/University of Massachusetts Amherst

Fire, as Balch pointed out, is a normal part of life. “From making breakfast on a gas-powered stove in the morning, to turning over the car’s combustion engine ignition, people use fire every day,” Balch said. The causes of wildfires often are part of daily life, too: a cigarette flung from a car window; a power line arcing when everyone runs the air conditioner at once; a spark hitting dried vegetation when a motorist on the side of the road starts her engine.

And while lightning-caused fires typically occur during the summer, human-caused fires are spread out throughout the year. Nationally, the fire season has grown by three months on average.

Balch suggests her research points to the need to rethink current fire management practices. “Over a hundred years of fire suppression hasn’t worked. We haven’t put fire out,” Balch said. “We need to think through how we sustainably live with fire and promote more prescribed burns.”

In the past, people have been resistant to controlled burns near communities. People don’t like living near the “patchwork patterns” of a burned landscape, Balch said.

And yet humans invite fire into their lives, sometimes just for the fun of it: The most common day for wildfire ignitions in the United States was July 4, with 7,762 fires burning more than 350,000 acres in 21 years.

“Things might have been different if Independence Day was in winter,” Balch said.

Note: This story has been updated to correct the number of fires started by humans between 1992 and 2012.

Maya L. Kapoor is an associate editor at High Country News.

High Country News Classifieds
  • DESCHUTES LAND TRUST EXECUTIVE DIRECTOR
    Deschutes Land Trust, based in Bend, Oregon, seeks a collaborative and strategic Executive Director to lead us in pursuing our mission: to conserve and care...
  • DEVELOPMENT MANAGER
    Job Title: Development Manager Supervisor: Senior Director of Development Effective Date: May 17, 2021 Job Status: Full-time (40 hours/week), exempt Location: Within the Colorado Plateau...
  • EXECUTIVE DIRECTOR AT FRIENDS OF CEDAR MESA
    - The Land, History, and People of the Bears Ears Region - The Bears Ears and Cedar Mesa region is one of the most beautiful,...
  • EXECUTIVE DIRECTOR
    Job Title: Executive Director Reports To: Board of Directors Compensation: $75,000 to $80,000, plus generous benefits and paid leave. Funding for relocation expenses available. Classification:...
  • WATER DIRECTOR
    Applications will be accepted on a rolling basis. Application review will begin on April 2, 2021 and will continue until the position has been filled....
  • CLIMATE JUSTICE FELLOW
    High Country News, an award-winning magazine covering the communities and environment of the Western United States, seeks applicants for a climate justice fellowship. The fellowship...
  • VIRGINIA SPENCER DAVIS FELLOWSHIP
    High Country News, an award-winning magazine covering the communities and environment of the Western United States, is offering a fellowship for early-career journalists interested in...
  • COLORADO WILD PUBLIC LANDS VIDEO CONTEST
    Please submit your video of 30 seconds or less, taken on public lands, to [email protected] by May 15th for a chance to win in one...
  • WMAN NETWORK COORDINATOR
    WESTERN MINING ACTION NETWORK (WMAN) CONTRACT OPPORTUNITY CLOSING DATE: Feb. 19, 2021 WMAN is seeking a team member to coordinate the various network activities to...
  • FRIENDS OF THE INYO IS HIRING TRAIL AMBASSADORS FOR THE SUMMER OF 2021
    Friends of the Inyo's Trail Ambassadors (TAs) support the Inyo, Sierra, & Humboldt-Toiyabe National Forests and other partners by providing positive public service, outreach, interpretation,...
  • LAND & CABIN ON CO/ UT LINE
    18 ac w/small solar ready cabin. Off grid, no well. Great RV location. Surrounded by state wildlife area and nat'l parks.
  • MANAGER PERMACULTURE LANDSCAPE CONTRACTOR
    Permaculture / Landscape Company Manager / Site Lead Red Ant Works, Inc. - 20+ year landscape construction and horticultural care company seeks manager and site...
  • CANYONLANDS FIELD INSTITUTE
    Field seminars for adults in natural and human history of the Colorado Plateau with lodge, river trip and base camp options. Small groups, guest experts.
  • COMMUNICATIONS MANAGER
    San Juan Citizens Alliance is looking for a passionate, dynamic, organized, and technology-savvy communications professional to help grow our membership and presence in the Four...
  • ENERGY AND CLIMATE PROGRAM ASSOCIATE
    San Juan Citizens Alliance seeks an Energy and Climate Program Associate to focus on public outreach, education and organizing to advance campaigns to mitigate climate...
  • REAL ESTATE SPECIALIST
    This position provides professional real estate services and is responsible for managing and completing real estate projects utilizing a project management database that is designed...
  • WILDFIRE MITIGATION SPECIALIST
    The Wildfire Mitigation Specialist is responsible for delivering wildfire risk mitigation information, recommendations and programmatic resources to wildland urban interface homeowners, community members and partners....
  • DEVELOPMENT POSITIONS
    Thorne Nature Experience is hiring for a Development Director and Senior Individual Giving Manager. Individuals will work collaboratively with Thorne's Executive Director to develop and...
  • WESTERN NATIVE SEED
    Native plant seeds for the Western US. Trees, shrubs, grasses, wildflowers and regional mixes. Call or email for free price list. 719-942-3935. [email protected] or visit...
  • THE LAND DESK: A PUBLIC LANDS NEWSLETTER
    Western lands and communities--in context--delivered to your inbox 3x/week. From award-winning journalist and HCN contributor Jonathan P. Thompson. $6/month; $60/year.