Second part in a series.

While wildfires are almost always the result of human activity, climate change is altering wildfires and how they’re managed.

North Carolina Forest Service Public Information Officer Philip Jackson said that while nearly all wildfires in the state correlate with human activity, climate change is affecting the nature of wildfires different ways.

First, the way precipitation falls is changing and becoming more extreme, Assistant State Climatologist Corey Davis said in an interview. “Instead of rain evenly spread out throughout a season or year, heavier rainfall is happening on fewer days with longer dry spells in between.”

Warming temperatures are an important part, too, and are making dry spells more severe and prone to wildfire activity. This has been especially apparent within the past few years. Last fall and again in June of this year, the state slipped into drought after just a few weeks of hot, dry weather.

“At both times, parts of the state went more than 20 days in a row without a drop of rainfall all while we were dealing with unseasonably warm temperatures — above 100 degrees in some areas earlier this summer,” Davis said. “Just like in your backyard garden, forests and other fire-prone ecosystems dry out in a hurry during times like that, and that brings the threat of wildfires.”

The State Climate Office, based in Raleigh, uses a handful of tools to monitor climate change and its effects, including measuring and archiving weather observations from more than 350 weather stations across the state, almost half of which have at least 30 years of historical observations.

Davis said this helps with understanding not only what current conditions are like, but also how conditions are changing, “and we’re consistently seeing more extremes in all directions.”

Most recently, that has been record rainfall totals in from Hurricane Helene in western North Carolina. Earlier this summer, conditions were extreme heat and dry weather. Davis’ office can use that kind of historical data to add context to those events. He cited Greenville as an example: The Pitt County city saw its longest streak of dry weather — 23 consecutive days without rainfall — since the fall of 2000.

The office is involved with research and partnerships that are helping explore climate change and its impacts, as well.

“Heat-mapping campaigns have shown us how much hotter certain parts of cities can get depending on their land use and land cover. There are applications there for forests, too, since we’ve found at a very micro scale on NC State’s campus, for instance, how bare ground and a lack of tree cover can affect surface temperatures,” he said.

That data, research and those partnerships all came together in the North Carolina Climate Science Report that the state climate office helped compile in 2020.

The report includes some key findings and projections related to wildfires, including a projected 300% or more increase in the number of weeks with the risk of very large fires, or burning more than 5,000 hectares – nearly 12,400 acres – by the middle of this century, compared to the end of the last century.

“And it notes that increases in temperatures and associated drying rates are very likely, with future droughts very likely to be warmer with a higher chance of wildfires,” Davis said.

Temperatures across the state are trending warmer in all four seasons, but it’s especially remarkable how much winters have been warming. According to the Climate Trends Plotter tool, the winter average temperatures in eastern North Carolina have been increasing by 0.5 to 0.75°F per decade over the past 50 years, and by more than 1.5 degrees Fahrenheit per decade in most areas since the year 2000.

“That’s having the effect of shrinking our winter seasons, and on the shoulders especially in February, we’re seeing more spring-like weather. That’s threatening to begin our spring fire seasons even earlier, and have them last even longer,” Davis said.

“We also see those changes reflected in future projections,” he continued, siting one study that projects a 74% increase in the area burned by lightning-caused wildfires in North Carolina between 2011 and 2060. “That’s a product of both longer fire seasons and warmer temperatures throughout the spring that make fuels more susceptible to burn.”

Other research shows more than a 200% increase in the number of days with suitable conditions for very large wildfires, which burn more than 12,000 acres, along the state’s coastline.

“Historically, these events have been very rare since they require all of those weather ingredients — extreme dryness in place with warm temperatures, low humidity, and high winds — for fires to grow that large in our region. But they’re expected to happen more often in the future,” Davis said.

Prescribed burns and climate change

Jackson explained that prescribed burns benefit forests and wildlife while reducing the risk and impacts of future catastrophic wildfires. The goal for these hazard reduction burns is to reduce the understory shrubs, vines, woody debris, needles and leaves that may be available to burn during unplanned wildfires.

“We will burn it in a planned manner that is of lower intensity, eliminating those fuel sources, helping prevent future wildfires or minimizing impacts from future wildfires. Low intensity prescribed fire also helps manage forestlands where many species require frequent burns to establish and thrive,” Jackson said.

The Forest Service also uses prescribed fire for site preparation purposes, also known as site-prep burns.

“These prescribed burns occur after harvesting to assist with reforestation activities. It allows for planting natural regeneration of tree seedlings, it’s less invasive and damaging than mechanical site preparation and is sometimes conducted as a pre-treatment to tree planting,” Jackson said.

Davis said that there’s been a lot of success with prescribed burns in North Carolina, and even though there’s still wildfires, those events are typically more manageable and less severe because of proactive prescribed burning practices, “But it’s already getting tougher to find windows to do this burning, and that problem is expected to become even worse in the future,” for a few reasons.

One, North Carolina is a fast-growing, fast-developing state, and we’ve got more acreage classified as wildland-urban interface than any state in the country, Davis explained.

“That means when we want to do burns in these natural areas, it’s more likely that people will notice it, so land and fire managers have to be very careful about burning when the wind direction is just right and making sure burns don’t linger overnight, when smoke can get trapped near the ground,” Davis said. “But climate change is also affecting our ability to burn. We’re getting fewer of those Goldilocks days when it’s not too wet or not too dry to have a successful burn, and the rapid changes from wet to dry patterns are making it tough to anticipate those periods.”

Historically, the most common times for burning in the spring and summer are becoming less suitable for burning as conditions then are hotter and drier, Davis said.

He explained that a study of the Southeastern United States looked at the suitability of prescribed burning based on projected weather conditions, and it found a sharp decrease in the number of suitable days in the transition seasons, or spring and fall, with the summer expected to become almost entirely unsuitable for burning by the end of the century.

“That’s largely driven by the warming temperatures, which makes the atmosphere less stable, the vertical transmission of heat and dispersion of smoke less predictable, and fuels drier so that they burn hotter and flames spread more quickly,” Davis said. “That’s all adding up to a big concern that we’ll see more frequent and more severe wildfires, with fewer opportunities to manage our forests in North Carolina to help avoid those events.”

Jackson said that the Forest Service predetermines weather and fuel parameters needed in order to safely execute a prescribed burn operation.

“If the weather doesn’t produce the ideal conditions that we need to safely carry out a burn, we simply won’t do it,” Jackson said, explaining that he has driven two hours to Stokes County, geared up in full personal protective equipment along with a dozen other personnel to conduct a prescribed burn, “only to cancel it before ever lighting a torch and putting fire on the ground. The weather either gives us what we need to carry out a burn safely, or it doesn’t. And if it doesn’t, we simply live to fight another day.”

First of two parts

As the fall wildfire season begins in North Carolina, the lead agency that responds to these uncontrolled fires in natural areas encourages residents be vigilant while burning outside.

“I’d like to remind folks about the importance of exercising caution with all outdoor fires, especially yard debris burns,” North Carolina Forest Service Division Public Information Officer Philip Jackson told Coastal Review.

Human activity causes 99% of North Carolina’s wildfires. Of that 99%, nearly half are caused by careless debris burning and escaped yard debris burns, which is the leading cause of wildfires across the state each year, Jackson said. The other 1% of uncontrolled fires are caused by natural ignition such as lightning.

“Fire activity has remained low over the last few weeks due to tropical storms and other rain events. However, as is the case most year’s during the month of October, we expect October to dry out some over the coming weeks, increasing fire activity,” Jackson said Wednesday.

Assistant State Climatologist Corey Davis told Coastal Review that there are three main components that each make for ideal wildfire conditions in eastern North Carolina: the time of year, the weather, and the ecosystem.

From late February through mid-April, grasses and other vegetation are coming out of their winter dormancy. Before the vegetation becomes fully green, they’re still pretty dry and flammable.

Deciduous trees are budding during this time, as well. But again, before the leaves have fully emerged, the leaves and trucks are fairly flammable. Without those leaves, they don’t offer as much shade for the vegetation beneath them, which helps it dry out even more, Davis explained.

These circumstances lead to the weather component.

“Warm and sunny days during the spring can cause environmental conditions to dry out more quickly, and as we receive more direct sunlight throughout the season, that can also cause fast-drying conditions in our forest fuels, which includes that not-yet-green vegetation and any dead woody material or litter covering the ground,” Davis said.

In addition to having those summer-like characteristics such as hot days with lots of sunshine, the spring is ultimately a transition season, and one feature of the winter climate that can carry over into the spring is lower relative humidity. “When we get one of those less humid air masses in place during the spring, especially after a warm period, then those dry fuels can be especially crispy and ready to burn,” Davis explained.

Last, there are a few different types of ecosystems in eastern North Carolina where we typically expect to see wildfires. Much of the southern and central coastal plain was once covered by native wiregrass pine savannas, where fires are a natural and common feature, happening every two to five years.

At low intensity, these fires are beneficial since they clear out competing vegetation and thin out the canopy so that native species like Carolina wiregrass and longleaf pines can thrive.

“Over the past century or so, the prevalence of these longleaf pine ecosystems has drastically declined across the region, Davis explained. This is because the trees were cut down initially for timber and naval stores such as tar, pitch, and turpentine, and more recently because of conversion to agricultural lands and other development.

“Where we do still have wiregrass ecosystems, the longleaf pines have been replaced by less fire-tolerant species such as loblolly, so fires may not be as effective. Historical fire suppression in these areas means that more fuels have built up within them, so when they burn now, it tends to be at higher intensity, which is both less beneficial and more likely to become difficult to control or contain,” Davis said.

The other major fire-prone ecosystems in eastern North Carolina are the pocosins near the coastline in places like the Pocosin Lakes National Wildlife Refuge in Hyde, Tyrrell and Washington counties.

“These are fairly low-lying areas where the water table is usually very high, often submerging the soils and creating a peat swamp sort of environment. But during times of drought, the water table drops and that highly organic soil dries out, which makes it very easy to burn,” Davis said.

These types of wildfires are tough to contain because of how remote and inaccessible many of these locations are, and because the fire can burn into the ground and consume the soil itself.

“There’s no easy way to extinguish them except for flooding the soil with as much water as possible or waiting for help from the rain so the water table rises again. Until that happens, these fires can burn and smolder for weeks or months, all while releasing lots of smoke that can be carried by the winds to different corners of the state,” Davis said.

“For those reasons, these pocosin areas have historically seen our state’s largest wildfires, and continue to be an area of concern any time there’s a springtime dry spell,” such as the April 2023 fire in the Croatan National Forest.

“Putting all of that together, the perfect conditions for wildfires in eastern North Carolina would be in late March or early April following a month or so of unseasonably warm and dry weather.”

Davis continued that with vegetation either dormant, dead or not green just yet, the environment would be highly flammable.

“The spark for fires could come from human activity like debris burns, or on a larger scale from lightning strikes along a strong cold frontal passage. Behind that front, a dry and less humid air mass would move in, and gusty winds would spread any newly ignited fires quickly across the landscape,” he said.

By late September, “these same trends from the spring happen again, but in reverse. Our temperatures can remain relatively warm well into October, and once trees drop their leaves, they ramp up the fuel loading at the surface,” according to the climate office.

So far in 2024, the Forest Service has responded to more than 3,500 wildfires for roughly 13,000 acres, Jackson with the Forest Service said.

The 2023 fall wildfire season was extremely active with nearly 2,000 wildfires statewide, more than 1,200 of which burned in November 2023 alone, Jackson said. “That was during our traditional fall wildfire season where fire risk is elevated, but we had also experienced prolonged drought conditions for much of the fall last year.”

“This is consistent and on pace with what we typically see each year. We usually experience between 4,500 and 5,500 wildfires annually. Frequency and duration are heavily influenced by weather conditions and time of year,” Jackson said, adding that over the last two months, “we’ve seen 119 wildfires for less than 50 acres. That’s considered to be rather quiet in terms of new wildfire starts and minimal acreage, largely due to the amount of rain our state has received recently.”

Jackson said that there’s a common misconception that wildfires are only an issue in the Western United States.

“The American South experiences more wildfires each year than any other region in the U.S.,” Jackson said. “While wildfires in the Western U.S. tend to be more severe while consuming larger chunks of acreage, wildfires in the Southeast U.S. are becoming more common.”

North Carolina had the third most wildfires nationally in 2022, behind only Texas and California. That same year, Texas, California, North Carolina, Georgia and Oklahoma accounted for nearly half of the total wildfires in the U.S.

The wildland-urban interface a big reason why. The wildland-urban interface, or WUI, is where development meets forestland. Three of the top four states with the most homes in the wildland urban interface are states located in the South, with North Carolina in the lead.

“North Carolina remains the leading state in the U.S. relative to number of acres in the wildland urban interface. As North Carolina’s population continues to grow, we’ll likely see more people living and recreating in the wildland urban interface,” Jackson said. 

With almost all wildfires in the state correlating with human activity, as the population increases, more people living and recreating in the wildland urban interface, potentially resulting in an increase in the number of wildfires our state experiences.

Statewide, between 2010 and 2020, 41,551 wildfires burned 399,125 acres, and from 1990 to 2010, North Carolina saw an increase of 3,005,048 acres in the wildland-urban interface.

“North Carolina’s WUI Risk Index estimates 2.3 million acres are at risk for moderate to major impacts from wildfires to people and their homes,” Jackson said.