Research conducted by fire scientist Anthony Westerling shows that between 1973 and 1982, fires burned for an average of six days. Between 2003 and 2012, this number skyrocketed to nearly seven and half weeks (52 days). This builds upon previous research published a decade earlier, which found an increase in average fire duration to more than five weeks.
"So long as there is fuel and it doesn’t rain or snow, a fire can burn, and burn, and burn," Pyne said. (He cited the exceptionally long-burning Chinchaga Fire, which raged from May through October in 1950.)
These numbers show when a fire has been "controlled," a somewhat blurry definition generally meaning that firefighters have contained the fire's perimeter, and the likelihood of flames or embers escaping is quite small, said Pyne. It doesn't mean the fires are completely out.
This is a critically important indicator for the millions living in the urban-rural fire interface, for example, Redding, California.
But deep inside the woods, the flames can continue.
"It's not like a house fire — it can burn and smolder for a long time," said Pyne. "When you're talking about something that's 300,000 acres, are you going to be able to go in with shovels on your back and put out every ember?"
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