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
  • SECLUDED COLORADO HIDEAWAY
    This passive solar home sits on 2 lots and offers an abundance of privacy and views while being only 15 minutes to downtown Buena Vista....
  • COMMUNICATIONS COORDINATOR
    Introduction: Grand Staircase Escalante Partners (GSEP) is a non-profit 501(c)(3) organization with offices located in Kanab and Escalante, Utah. We are committed to the conservation...
  • CARETAKER
    2.0 acre homestead needing year-round caretaker in NE Oregon. Contact [email protected] for details.
  • MEMBERSHIP MANAGER
    For more information visit www. wyofile.com/careers/
  • THRIVING LOCAL HEALTH FOOD STORE FOR SALE
    Turn-key business opportunity. Successful well established business with room to grow. Excellent highway visibility.
  • DEVELOPMENT DIRECTOR
    For more information, visit www.wyofile.com/careers/
  • STAFF ATTORNEY
    STAFF ATTORNEY POSITION OPENING www.westernlaw.org/about-us/clinic-interns-careers The Western Environmental Law Center (WELC) is a high-impact, nonprofit public interest environmental law firm with a 27-year legacy using...
  • PROJECT MANAGER
    Position Summary Join our Team at the New Mexico Land Conservancy! We're seeking a Project Manager who will work to protect land and water across...
  • SEEKING PROPERTY FOR BISON HERD
    Seeking additional properties for a herd of 1,000 AUM minimum. Interested in partnering with landowners looking to engage in commercial and/or conservation bison ranching. Location...
  • DIRECTOR OF PRODUCT AND MARKETING
    High Country News seeks a Director of Product and Marketing to join our senior team during an exciting chapter of innovation and growth. This individual...
  • WILDLIFE HAVEN
    Beautiful acreage with Teton Creek flowing through it. Springs and ponds, lots of trees, moose and deer. Property has barn. Easy access. approx. 33 acres.
  • ARIZONA CONSERVATION CORPS PROGRAM DIRECTOR
    Arizona Conservation Corps is seeking a Program Director in Flagstaff or Tucson
  • COPPER STAIN: ASARCO'S LEGACY IN EL PASO
    Tales from scores of ex-employees unearth the human costs of an economy that runs on copper.
  • EXPERT LAND STEWART
    Available for site conservator, property manager. View resume at http://skills.ojadigital.net.
  • CONSERVATIONIST? IRRIGABLE LAND?
    Stellar seed-saving NGO is available to serious partner. Package must include financial support. Details: http://seeds.ojaidigital.net.
  • CANYONLANDS FIELD INSTITUTE
    Colorado Plateau Natural & Human History Field Seminars. Lodge, river, hiking options. Small groups, guest experts.
  • WESTERN NATIVE SEED
    Specializing in native seeds and seed mixes for western states.
  • CHUCK BURR'S CULTUREQUAKE.COM BLOG
    Change will happen when we see a new way of living. Thinking to save the world.
  • COMING TO TUCSON?
    Popular vacation house, furnished, 2 bed/1 bath, yard, dog-friendly. Lee at [email protected] or 520-791-9246.
  • OJO CALIENTE COMMERCIAL VENTURE
    Outstanding location near the world famous Ojo Caliente Mineral Spring Resort. Classic adobe Mercantile complete w/living quarters, separate 6 unit B&B, metal building and spacious...