Smallest spark can ignite biggest blaze
All it takes is a spark.
Deadly wildfires such as the ones raging in California this week can begin with something as simple as a downed power line, a flat tire or a tossed cigarette butt.
That spark, combined with tinderdry forests and howling winds, can be all that’s needed for a catastrophic wildfire to start. Once a fire ignites, the combination of heat, oxygen and fuel (trees, brush) can cause it to explode in size.
At its height, the Camp Fire burned the equivalent of 60 football fields a minute. That fire is the deadliest and most destructive in California.
About 84 percent of wildfires in the USA are started by people, according to a comprehensive study in 2017 published in the Proceedings of the National Academy of Sciences.
Hot, dry weather this summer and fall has been a factor: “Over the past two months, the areas now burning have had far less precipitation than normal for this time of year while experiencing above-average temperatures,” said Jacob Bendix, a geographer at Syracuse University.
UCLA climate scientist Daniel Swain said that “if Northern California had received anywhere near the typical amount of autumn precipitation this year (4 to 5 inches of rain near the Camp Fire point of origin), the explosive fire behavior and the stunning tragedy in Paradise would almost certainly not have occurred.”
It was also very hot: “The entire state was above average with the Sierra Nevada region (the Camp Fire location) having the warmest summer on record,” Swain said.
“Thus, conditions were primed for fire,” Bendix said.
Development makes wildfires more costly and dangerous by putting more homes in areas that carry a high risk of fires. Plain and simple, “we are building more homes in the line of fire,” University of Colorado geographer Jennifer Balch said.
As of 2010, about 43 million homes in the United States were in what scientists call the “wildland-urban interface,” the area where residential homes are built on or near wildland vegetation, such as trees and shrubs. Twenty years earlier, 31 million homes were in those areas.