“We have California wildfires in North Carolina.”
— North Carolina’s Gov. Pat McCrory, quoted by ABC News.
Wildfire that has killed at least seven people as of Thursday morning on the doorstep of Great Smoky Mountains National Park, while emptying the gateway towns of Gatlinburg and Pigeon Forge, is more destructive than Tennessee has seen in over a century.
The event also part of a worsening, widening pattern of wildfire across North America in recent decades: The biggest blazes are not only larger and more intense but are occurring well outside their normal range of California, Arizona, Idaho and elsewhere in the arid West.
This year seems to be the Southeast’s turn, with more than 160,000 acres burned in fires of unusual size and intensity. (That’s not much territory in the West; in the Southeast it is historic.)
Last year, fires burned at unprecedented scale in the rainforests of Washington State’s Olympic Peninsula, as well as unaccustomed portions of Alaska. In Canada, parts of Saskatchewan and Alberta suddenly found themselves up against record-setting walls of flame.
Of course, the 2015 fire season was the worst in the U.S. for any year with record-keeping. Some 10.1 million acres burned; suppression costs ran to $1.72 billion and 13 firefighters’ lives. Five civilians died in California and 4,500 homes were lost.
Even then, the danger of big fires was elevated in a stretch of the Appalachians from Pennsylvania down through the Smokies.
But by this spring, when the National Interagency Fire Center issued its outlook for significant wildland fire in 2016, the maps showed risk returning to normal levels in the mountains.
Nationwide, the outlook was for normal conditions in the rest of the Southeast, and normal to below-normal risk elsewhere excepting Hawaii, a small portion of Alaska and the southern half of Arizona.
As of Wednesday evening, the 2016 fire season by national measures is about half the size of last year’s and also below the 10-year rolling average for this point in the calendar, according to NIFC: 60,146 fires versus 66,421; 5.27 million acres burned versus 6.78 million.
But nearly 100,000 acres were ablaze in 15 large fires, four of them new, all of them in the Southeast: eight in North Carolina, three in Georgia, one each in Alabama, South Carolina, Virginia … and Tennessee.
At the moment, all of the significant wildfire action in the country is in this region.
Light rain, little relief
“Chimney 2” is the name given to the fire that has now emptied Gatlinburg, Pigeon Forge and also the most-visited national park in America; it was closed to visitors after the park headquarters lost electric power and phone service.
As of Thursday morning, some 16,000 acres had already burned and the fire was only 10 percent contained. Seven people were dead and at least 53 had been sent to hospitals. Some 700 homes, business and other structures were estimated to have been damaged or destroyed. Spates of light rain Tuesday and Wednesday brought little relief, but contributed to mudslides in burned-over areas.
By comparison, the Fort MacMurray fire, at the edge of the Alberta tar sands, that seized world attention six months ago caused no direct fatalities (two people died in a car crash during the evacuation). The final count of destroyed structures well exceeded 2,000 and the burned acreage reached 1.5 million acres. It was the costliest disaster, and largest evacuation (88,000 people), in Canadian history.
The evacuation of roughly 15,000 residents and visitors in Gatlinburg and Pigeon Forge came on even shorter notice and was complicated — as were rescue efforts — by a pattern of residential development scattered over mountain terrain. It seems possible that the death toll will rise, and certain that it will be some days before officials can be confident they have found all the bodies.
The park’s superintendent, Cassius Cash, says the fire was likely to have been “human-caused,” which is pretty much a given. According to a U.S. Geological Survey email I received last week, “As many as 90 percent of wildland fires in the United States are caused by humans, primarily through campfires left unattended, burning of debris, negligently discarded cigarettes and intentional acts of arson.” (In second place, distantly, is lightning.)
But if people strike the match, it is climate and weather that lay the fuel.
A serious drought has plagued the Southeast this year, but it is not of historic proportions regionally; conditions in 2007 were about as bad.
What seems to be a little different this year is how late in the year the dry conditions have persisted. October is usually the most fire-prone month in the Southeast, but this year November was worse, and there are scattered examples of extraordinarily dry conditions. Some places cited by Climate Central for having “set records for consecutive days without measurable rain”:
On Nov. 21, Tuscaloosa, Ala., ended a stretch of 65 dry days, beating its previous record of 37…. Cedartown, Ga., has gone an astounding 94 days, crushing its previous record of 36. Asheville, N.C., is still maintaining its streak of dry days, counting 32 so far. Its record is 39.
Drought likely to persist
Experts told The Insurance Journal that there’s little chance of rain arriving in amounts that can correct the situation in the near term:
“After weeks of punishing drought, any rain that falls should be soaked up quickly, forecasters said. It will provide some relief but won’t end the drought — or the fire threat, they say.
Drought conditions will likely persist, authorities said. The problem is that rainfall amounts have been 10 to 15 inches below normal during the past three months in many parts of the South. …
“I think we racked up deficits that are going to be too much to overcome with just one storm system,” said Mark Svoboda, director of the National Drought Mitigation Center in Lincoln, Nebraska.
Indeed, the outlook maps produced by Svoboda’s staff and collaborators at NASA, the University of Nebraska and the U.S. Department of Agriculture show current drought conditions persisting through the fire region — and much of the rest of the Southeast — through February, and also worsening toward the Atlantic Coast.
As usual, coverage of the fires in the Southeast is peppered with observations of scientists that no single fire or fire season can firmly be attributed to climate change, though the principal conditions that drive big fires — warmer temperatures, drier air, higher winds, deeper and longer droughts — are clearly associated with observed climate shifts.
Climate change’s contribution
So it remains a difficult question to apportion blame, if we want to call it that, to climate disruption versus normal weather variation. But an interesting study published at the end of last month in the Proceedings of the National Academy of Sciences parsed the contributions of various factors and reached this provocative conclusion (my emphasis added):
Anthropogenic increases in temperature and vapor pressure deficit significantly enhanced fuel aridity across western U.S. forests over the past several decades and, during 2000—2015, contributed to 75% more forested area experiencing high fire-season fuel aridity and an average of nine additional days per year of high fire potential.
Anthropogenic climate change accounted for ∼55% of observed increases in fuel aridity from 1979 to 2015 across western US forests, highlighting both anthropogenic climate change and natural climate variability as important contributors to increased wildfire potential in recent decades.
We estimate that human-caused climate change contributed to an additional 4.2 million ha [10.4 million acres] of forest fire area during 1984-2015, nearly doubling the forest fire area expected in its absence.
These calculations can’t be applied directly to the forests of the Southeast for many reasons, perhaps the largest being that while such sources as the National Climate Assessment expect the regional climate to keep getting warmer, there is less consensus about whether the changes in precipitation patterns will result in wetter or drier conditions overall.
But as the Chimney 2 fire demonstrates so well, wetter conditions in general don’t necessarily make a forest fireproof.
It’s not just how much rain falls, or where — it’s also when.
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