Wednesday, November 23, 2016

What a Warmer Future Means for Southeastern Wildfires

A heavy air tanker drops fire retardant over the Boteler wildfire near Hayesville, N.C., on Nov. 10. Credit: Reuters / Michael David Chiodini) Click to Enlarge.
‘A Carpet of Fuel’
Nearly three dozen large wildfires are burning across seven states in the Southeast, charring a total of more than 100,000 acres.  The fires in the worst-hit states, Georgia and North Carolina, have burned about 45,000 acres in each state.

Thousands of firefighters have descended on the region to quash and contain the flames at the cost of millions of dollars.  In the meantime, residents even hundreds of miles away have had to deal with air quality alerts and curb their outdoor activities as shifting winds spread the fires’ smoke.

While the Southeast is no stranger to wildfires, the number so far this fall is “many, many more than what we normally have,” Chip Konrad, director of the Southeast Regional Climate Center, said.  And the sheer scale of some of them is far larger than is typical for the Appalachians.

The Southeast often experiences a secondary fire season in the fall, as October is typically the driest month of the year for many parts of the region.  But the bone-dry conditions this year have added considerable fuel to the flames.
Future Fire
What climate change might mean for drought and wildfires in Southeast in the future is a tricky question.  Unlike some areas of the country, like the Southwest, climate models differ on how overall precipitation in the region might change as temperatures rise.

Those rising temperatures are the clearest tie-in with climate change for future drought.  “Most definitely we’re seeing an increase in the frequency of above-normal temperatures,” Konrad said.

More days of high heat means that when the region does see a drop-off in precipitation, “you can go into drought more quickly,” Konrad said.  Some of that effect was seen in late summer and early fall this year, as the drought in the Southeast rapidly deepened and expanded.

Some of the same factors that limit what can be said about future droughts also limit projections of future wildfire risk.

“There’s so much uncertainty on the precip that it’s really hard to say what the future’s going to be,” Prestemon, of the Forest Service, said.

Wildfires are also very complex, with myriad factors contributing to them.  A study published earlier this year and led by Prestemon used both climate models and projections of societal changes, like population growth and development, to look at how they might impact wildfire projections.

They found that societal changes suggested a small reduction in the area burned by human-caused fires (which account for the bulk of wildfires in the Southeast) by mid-century, likely because development reduced the amount of forests and created more breaks that could stop the spread of fire.  Conversely, changes in climate suggested lightning-started fires would burn larger areas.

Prestemon stresses that the findings aren’t a forecast, merely a look at what’s possible and how different factors influence wildfire activity.

But, as with drought, the fact that temperatures are steadily rising and making extreme heat more common could make wildfires like these more likely to occur in the future with the right conditions.

Read more at What a Warmer Future Means for Southeastern Wildfires

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