The suburbs evoke images of white picket fences and organized sports, a peaceful escape from big-city living. But new research finds verdant residential communities are increasingly likely to go up in smoke.
In an analysis of more than 23 million fires, a study published this week in the journal Nature Ecology & Evolution finds a cluster of “economically and socially disastrous” fires, or megafires as they're sometimes called, have scorched suburban neighborhoods, especially across the western U.S. and southeastern Australia.
More communities could be at risk. Warmer and longer winters, prolonged drought, and other impacts from a changing climate could boost the number of days conducive to extreme fire events by 35 percent, the study found.
“The finding that climate change increases the seasonal windows of opportunities of high fire danger in the geographic areas where these fires become disasters suggests that climate change is a threat multiplier to the wicked fire problem that these communities face today,” said John Abatzoglou, a co-author of the study and associate professor at the University of Idaho.
Using MODIS satellite images, the authors created a global database of fire events that occurred between 2002 and 2013. Of the top 478 extreme wildfires — those that exhibited extreme behaviors, such as growing to massive sizes or burning hotter than expected — 30 percent were classified as “disasters,” in that they caused substantial economic or social harms.
The authors then set out to determine why some extreme fires became disasters. Abatzoglou said they found abnormal weather and climate conditions were a driving factor in 96 percent of the extreme fires identified.
Two-thirds of the fire events occurred on days with high fire danger, and nearly half of the events occurred during moderate-to-severe long-term drought, suggesting that low fuel moisture enables the occurrence of megafires, he said. Strong winds, which are known to promote rapid rates of fire spread, were found in about a third of the fire events.
David Bowman, a professor of environmental change biology at the University of Tasmania in Australia and lead author of the study, said he was motivated to map and analyze wildfires because his city, Hobart, Australia, was devastated by a megafire 50 years ago this month. Since then, the region has experienced many similarly deadly conflagrations, but it was hard to find a global fire database that could shed light on the relationship between extreme fires, climate and the impact of human development.
“Our study's publication on the 50th anniversary of the [sic] 1967 Tasmanian fire disaster is a fortuitous coincidence that helps highlight the global vulnerability of cities surrounding by flammable forests, regardless of climate change,” Bowman wrote in a “behind the paper” web post for Nature. “Disturbingly, the current global trajectory of low density housing in flammable forests, combined with rapidly increasing dangerous fire weather due to climate change, will lead to more fire disasters.”
Although the authors found destructive wildfires were concentrated in regions where humans have built into flammable landscapes, such as suburbs near forests and grasslands, not all regions of the world experienced similar levels of fire activity.
For example, the European Mediterranean, despite having a similar climate to the western U.S., did not have as many fires, the data showed.
With the impacts of climate change, that may not be the case moving forward. The study found more extreme fires are predicted along the Australian east coast and all Mediterranean countries, including Portugal, Spain, France, Greece and Turkey.
“As such, our results suggest that extreme wildfires impacting these southern European communities may simply be a matter of time,” Bowman said.
Reprinted from Climatewire with permission from E&E News. E&E provides daily coverage of essential energy and environmental news at www.eenews.net.