‘Flash drought’ in Hawai’i fuels deadliest U.S. wildfires in 100 years

As the death toll from the wildfire that incinerated Lahaina, Hawai’i climbs, the phenomenon of “flash drought” after decades of ecosystem-destroying plantation farming is emerging as a proximate trigger for the catastrophe.

At latest report, 96 were reported dead in the wildfires that consumed the historic town of Lahaina, with thousands left homeless, at least 2,200 buildings destroyed, and authorities trying to identify those lost by asking family members for DNA samples while warning that the search was in its early stages. Three days ago, officials said there may be as many as 1,000 people missing, and there are reports that Maui’s early warning systems failed to alert residents of the impending disaster.

Already, the Lahaina wildfires count as the deadliest in the U.S. in more than a century. The scale of the devastation surpasses the Camp Fire in California in 2018, which literally burned (another) Paradise to the ground. Insurable losses could run as high as US$6 billion, reports the Associated Press. And no financial accounting will be adequate to replace the cultural and spiritual riches lost to a catastrophe that many witnesses described as an “apocalypse.”

From ‘Flash Drought’ to Conflagration

At least for now, climate scientists expressed some caution when asked whether the wildfires that destroyed Lahaina and laid waste to swaths of drought-stricken west Maui were “caused” by climate change.

Erica Fleishman, director of the Oregon Climate Change Research Institute at Oregon State University, cautioned against drawing a direct line between Lahaina’s fate and global heating, absent a thorough analysis.

But “there are conditions that are consistent with wildfire, wildfire size, and expansion that are changing as climate changes,” she told CNN. “And some of the things that we’re seeing with this wildfire in Maui are consistent with some of the trends that are known and projected as climate changes.”

One of those trends is the drying out of vegetation, a process that can turn even the lushest of ecosystems into a tinderbox.

“Amid the devastating Maui fires, I see many arguing, ‘it’s weather, arson—anything but climate change’,” wrote veteran climate scientist Katharine Hayhoe, chief scientist at The Nature Conservancy. So “let’s set the record straight. Climate change doesn’t usually start the fires; but it intensifies them, increasing the area they burn + making them much more dangerous.”

The stage for such an intensification was surely set on the island of Maui this summer, and with shocking speed.

Citing the U.S. Drought Monitor, the Associated Press reports that Maui went from being unusually dry nowhere on the island on May 23, to being “either abnormally dry or in moderate drought” across 66% of its territory on June 13—in less than three weeks.

The speed with which Maui shifted into drought, or near-drought, fits the definition of a “flash drought,” University of Wisconsin atmospheric scientist Jason Otkin told AP.

Co-author of a study published in April in the journal Science which linked an increase in crop-destroying flash droughts to the “greater evapotranspiration and precipitation deficits caused by anthropogenic climate change,” Otkin cited a 2016 flash drought connected to “unusual wildfires in Gatlinburg, Tennessee” as a precedent for what occurred in Maui.

The Wall Street Journal says [pdf] Hawai’ian fire researchers warned of the extreme wildfire risk facing Lahaina almost a decade ago. “Another report, in 2020, tied fires to winds from a passing hurricane—similar to the ones that fanned the Lahaina blaze.”

Confirming a further “quick acceleration” in Maui’s drought in the days leading up to the wildfire, University of Virginia hydrologist Venkat Lakshmi said flash droughts leave super-dry air above land “literally sucking moisture out of the ground and plants, making them more likely to catch fire.”

When that happens, “plants are getting really, really dry. It’s all related to water in some ways,” Lakshmi told AP.

Then once Maui was on fire, the winds of Hurricane Dora—clocking in at more than 95 kilometres per hour, even though the Category 4 storm itself was hundreds of kilometres to the south—ensured the flames spread at terrifying speed.

“The massive winds, dry winds, are what drove this fire,” Josh Stanbro, chief resilience officer for Honolulu from 2017-2021, told the New York Times.  “This is part of a long-term trend that is directly related to climate changes and impacts on the islands.”

From Local Farming to Sugar Plantations to Invasive Weeds

Five years ago in July, kalo farmers in Lahaina’s Kahoma Valley harvested the region’s first kalo crop in 130 years.

“Maps from the 1850s and 1860s show that farmers were growing coffee, mango, and sugar cane on a small scale in the valley,” alongside extensive kalo operations, wrote Maui News at the time.

All of that local farming stopped when the sugar company Pioneer Mill Co. showed up and diverted all the available water into its sugar cane plantations.

Kahoma Valley was spared by its rugged topography from the bulldozing that so much of Maui suffered in the decades that followed from the incursion of other sugar and pineapple companies. But its karo farms were left to grow back into the forest until 2017, when Lahaina residents fulfilled a decades-old dream to restart them, by bringing the flow of water back into the rivers and streams of the valley.

But the sugar and pineapple plantations did not fare so well. Abandoned in the 1980s when companies like Dole decamped for jurisdictions with less stringent labour standards, those lands were swiftly taken over by Guinea grass, an invasive species that grows as much as 15 centimetres per day in the wet season, then turns to spectacularly effective tinder in the dry.

“These grasslands accumulate fuels very rapidly,” University of Hawai’i fire scientist Clay Trauernicht told AP. “In hotter conditions and drier conditions, with variable rainfall, it’s only going to exacerbate the problem.”

Elizabeth Pickett, co-executive director of the Hawaii Wildfire Management Organization, warned of a vicious feedback loop where increasingly intense fires leave native forests being replaced by more grass all over the island, a pattern showing up more and more in forest ecosystems the world over.

“Parts of the Amazon rainforest, the biggest in the world, are fast approaching” the tipping point where forestlands switch over into much drier savannah ecosystems, “a point of no return when the humid ecosystem would forever change,” the Times notes.

Trauernicht added that “abandoned plantations rarely have properly maintained resources that firefighters can use to fight fires: roads and water,” Spectrum Local Newsadds.

He said the firebreaks that would be created by a row of bananas or pineapples, or a strip of wetland taro, need urgently to be added back to the more than a million acres of terrain that are now overrun with guinea grass.

Above all, “we need to get those folks that do own these large parcels [absentee corporations, mostly] to really rethink what their responsibility is to the neighbouring communities,” said Trauernicht. “When we let these fields go fallow, and no actions are taken, this is the consequence.”