For years, each new wildfire season in Hawaii has promised to be riskier than usual. This year, wildfire experts and climate forecasters are predicting a particularly dry summer ahead, which could lead to an especially bad wildfire season.

One reason is the decline of sugar and pineapple plantations that’s allowed fire-prone exotic grasses — fountain, guinea and other fast-growing invaders — to flourish on fallow agricultural land during periods of heavy rain, thereby increasing the fire risk in bone-dry conditions.

The loss of productive farmland beginning in the latter part of the 20th century overlaps with the acreage that most often burns during fire season, says state Fire Protection Forester Michael Walker.

Climate change is another aggravating factor that’s making Hawaii wildfires increasingly aggressive, according to longtime county firefighters. It’s also expected to alter the geography of wildfire risk in step with shifting precipitation patterns.

As dry leeward areas become drier, they’ll lose out on rainfall that allows African grasses to thrive, thereby decreasing fire risk in established hotspots, according to Walker. The biggest fire risk is expected to gradually shift to new regions farther mauka, which have historically been too wet to easily ignite.

Humans are almost entirely to blame for wildfires in Hawaii. Nathan Eagle/Civil Beat/2019

Calculating the risk, however, is difficult. That’s because nearly 99% of the state’s wildfires are sparked by humans, with about three-quarters of them being accidental. Less than 2% are naturally occurring fires triggered by either lightning strikes or lava, according to University of Hawaii researchers.

“There’s all this perfectly cured fuel out there in the form of unmanaged grasses and it all just depends if someone makes a mistake by welding in high wind conditions or parking on tall grass or intentionally setting fires,” said Walker, who oversees the state Department of Land and Natural Resources’ Division of Forestry and Wildlife Forestry Program.

“So we could skate through the entire summer and be totally fine with no ignitions or there could be total catastrophe due to accidents and arson,” he said. “We just don’t really know what will happen.”

Arson is what authorities say happened in Central Maui last week, leading police to arrest three suspects in connection with six intentionally set fires ignited over the course of an hour.

The fires did not damage any homes, but authorities said it was a close call. Encouraged by wind and dry conditions, the fires triggered neighborhood evacuations and hours-long traffic snarls.

Nearly two-thirds of Hawaii’s acreage is abnormally dry, according to the U.S. Drought Monitor. The entire west end of Molokai and small pockets of Maui, Kahoolawe and the Big Island are already in extreme drought conditions.

“I like to call it the nouveau Hawaiian savannah,” Walker said. “If you can look outside at the landscape and it looks like it’s an African savannah but it doesn’t have gazelles and giraffes and things, you’re probably living in an area that’s highly susceptible to fire.”

‘Fires Are Going To Get Worse’

People tend to think of the western United States when conjuring images of devastating wildfires. But as a percent of total land area, Hawaii’s wildfires burn as much or more land each year than any other state, studies show.

University of Hawaii wildland fire researcher Clay Trauernicht has found that the area burned annually by wildfires in Hawaii has increased fourfold in recent decades. This is partially a product of climate change, which is bringing the islands wetter and stormier winters coupled with drier and hotter summers — conditions that intensify the wildfire threat, he said.

“If you asked me five years ago if climate change is affecting fires now I would probably have been pretty skeptical,” Trauernicht said. “But at this point, mostly from talking with firefighters that are on the front lines, they’re all pretty convinced that they’re seeing conditions that they haven’t encountered before.”

Wildfire researcher Clay Trauernicht says the African grasses and shrubs that have taken over Hawaii’s agricultural lands need to be managed to control wildfires. Courtesy: Clay Trauernicht/2019

The Mana Road fire that scorched more than 42,000 acres of mostly grassland last summer on the slopes of the Big Island’s Mauna Kea above Waimea was one of the largest wildland fires in recorded state history. It blackened more than double the annual average of 20,000 acres that typically burn statewide, according to a 2022 study.

Firefighters who battled the Mana Road blaze noted its abnormal intensity in terms of flame length and rate of spread, Trauernicht said.

“It was total luck that it didn’t come around and swallow up Waikoloa,” Traeurnicht said. “The wind switched. But there was no stopping it without that change in wind direction. With fires like Mana Road, we’re seeing the limits of fire suppression.”

In 2019, record-breaking heat exacerbated fire conditions on Maui where a total of 25,000 acres burned — more than five times the amount of scorched earth than the previous year. Authorities arrested a 28-year-old homeless man on charges of arson in connection with the largest blaze that summer that blackened 9,000 acres of mostly former sugarcane fields in a matter of hours.

When it comes to wildfires, firefighters are the last line of defense. Preventative measures, such as clearing and managing invasive grasses on large swaths of land, are expensive and laborious, but underutilized and effective insurance policies against future fire risk, Traeurnicht said.

“Fires are going to get worse,” Traeurnicht said. “But we actually know what to do about it. We know how to make our landscapes and our communities better adapted and more resilient. We just need the resources and the societal investment.”

Across DOFAW’s 1 million acres statewide, the majority of invasive grass clearing and maintenance is done mechanically with bulldozers and other heavy machinery or chemically with herbicide sprays. The agency uses these tactics to maintain wide strips of land called fuel breaks intended to slow the spread of fire across vast acreage while offering access to firefighters.

It can be relentless work. In optimal conditions, guinea grass can grow six inches per day.

“We just need the resources and the societal investment.” — Clay Traeurnicht, wildfire researcher

Prescribed fire is another underutilized method of exotic grass control commonly used to burn off invasive grasses along Maui’s Haleakala Highway and at the U.S. Army’s Schofield Barracks training range complex.

The mouths of hungry goats, sheep or cattle can also be deployed to feed on overgrown and highly combustible vegetation, thereby reducing fire risk while generating a revenue stream for ranchers.

Walker said the state doesn’t use herd animals to maintain its fire breaks, but he said it should consider doing so.

“It continues to be harder and harder to make any money from livestock these days because the profit margins are really, really tight for ranching in Hawaii,” Walker said. “So I see it as an opportunity for the public to benefit from grazing animals, and for ranchers to benefit as well because this could help sustain the livestock industry in this state.”

The proliferation of housing developments on former agricultural lands in recent decades presents another wildfire hazard that could be dampened by the development of a more robust farming sector, according to Walker.

“I think everyone knows the best and most profitable product that you can farm on ag land today is a house,” he said. “So you get brand new housing developments surrounded by invasive grass and now you’ve just created another fire problem.”

In this way, Hawaii’s food sustainability goals, which seek to revitalize the state’s once-thriving agriculture sector by putting the land back into production, could have positive effects for wildfire prevention.

Much of the state’s wildfire-prone acreage is privately owned, so DOFAW seeks out large private land owners to apply for federal grants to help with fuel reduction, since “fire doesn’t know political boundaries,” according to Walker. But there’s a need for more public-private landowner coordination, he said, as well as additional fuel reduction grant opportunities.

Walker said he’d like to see the state come up with a grant for ranchers, farmers and whole communities who want to invest in invasive grass management. Although there are federal funds available for this purpose, Walker said they don’t cover fence-building projects, for example, which could help ranchers deploy animal herds to clear and maintain fire breaks.

Civil Beat’s coverage of climate change is supported by the Environmental Funders Group of the Hawaii Community Foundation, Marisla Fund of the Hawaii Community Foundation and the Frost Family Foundation.

Civil Beat’s coverage of Maui County is supported in part by grants from the Nuestro Futuro Foundation and the Fred Baldwin Memorial Foundation.

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