title: Climate-induced variations in global wildfire danger from 1979 to 2013.
abstract: Climate strongly influences global wildfire activity, and recent wildfire surges may signal fire weather-induced pyrogeographic shifts. Here we use three daily global climate data sets and three fire danger indices to develop a simple annual metric of fire weather season length, and map spatio-temporal trends from 1979 to 2013. We show that fire weather seasons have lengthened across 29.6 million km(2) (25.3%) of the Earth's vegetated surface, resulting in an 18.7% increase in global mean fire weather season length. We also show a doubling (108.1% increase) of global burnable area affected by long fire weather seasons (>1.0 σ above the historical mean) and an increased global frequency of long fire weather seasons across 62.4 million km(2) (53.4%) during the second half of the study period. If these fire weather changes are coupled with ignition sources and available fuel, they could markedly impact global ecosystems, societies, economies and climate.
authors.affiliation: US Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, 5775 Highway 10 West, Missoula, Montana 59803, USA.
authors.forename: W Matt
authors.initials: WM
authors.lastname: Jolly
authors.affiliation: Geospatial Sciences Center of Excellence (GSCE), South Dakota State University, 1021 Medary Avenue, Wecota Hall, Box 506B, Brookings, South Dakota 57007, USA.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Cochrane
authors.affiliation: 1] US Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, 5775 Highway 10 West, Missoula, Montana 59803, USA [2] Geospatial Sciences Center of Excellence (GSCE), South Dakota State University, 1021 Medary Avenue, Wecota Hall, Box 506B, Brookings, South Dakota 57007, USA.
authors.forename: Patrick H
authors.initials: PH
authors.lastname: Freeborn
authors.affiliation: US Forest Service Region 1, 200 East Broadway Street, Missoula, Montana 59802, USA.
authors.forename: Zachary A
authors.initials: ZA
authors.lastname: Holden
authors.affiliation: Desert Research Institute (DRI), Western Regional Climate Center, 2215 Raggio Parkway, Reno, Nevada 89512-1095, USA.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Brown
authors.affiliation: School of Biological Sciences, The University of Tasmania, Private Bag 55, Hobart, Tasmania 7001, Australia.
authors.forename: Grant J
authors.initials: GJ
authors.lastname: Williamson
authors.affiliation: School of Biological Sciences, The University of Tasmania, Private Bag 55, Hobart, Tasmania 7001, Australia.
authors.forename: David M J S
authors.initials: DM
authors.lastname: Bowman