Pacific Islands wildfires highlight vulnerability to climate change and how to address it

Hawaii just experienced one of its largest wildfires at 40,000 acres on the northwest slope of Mauna Kea. However, calling the Mana Road Fire “unprecedented” or blaming it on climate change is misplaced. I argue instead that fire on Pacific Islands isn’t a story about climate as much as a lesson about how the trajectory of human society — and our relationship with the land — increases our vulnerability to many climate-related events. Put simply, human actions (and inaction) have created highly flammable landscapes across the Pacific Island region, which means these landscapes can be altered and restored to be less vulnerable to fire.

Hawaii has experienced large fires tied to drought before, including the first recorded “big burn” at 30,000 acres in 1901 and a 47,000-acre fire in 1969, both on the big island.

Climate change may be looming over more recent fires. In August 2018, abnormally low humidity allowed a complex of fires on west Oahu to burn nearly 5,000 acres through night and day, forcing evacuations across multiple valleys. July of 2019 broke records on Maui for both daily temperatures and fire, with more than 20,000 acres burning across the island’s central valley.

Yet, the sheer extent of fire in Hawaii and many “U.S.-affiliated” Pacific islands in Micronesia indicates factors beyond climate. A great example, the Mana Road Fire burned 1 percent of the Hawaiian Islands’ land area in a single incident. For context, a year’s worth of fires in California burn, on average, 0.7 percent of the state’s land area. Fires on Guam, Yap, Palau and the Northern Marianas in Micronesia greatly exceed these values. Guam averages nearly 4 percent of its total land area burned each year (equivalent to California’s worst year on record in 2020) and during its worst fire year, the El Niño-fueled drought of 1997 and 1998, 10 percent of the island burned.

These percentages illustrate how, despite smaller footprints, fires can devastate islands where “values at risk” — communities, forests, and nearshore coral reefs — are highly concentrated. Recurrent fires erode the edges of critical watershed forest, which grasses replace after burning. Fire scars increase erosion, allowing soil to wash down onto reefs, amplifying the stress of rising ocean temperatures.

Of course, we can’t forget that fires threaten human lives and highlight inequities in exposure. The Native Hawaiian community at Pu‘ukapu bore the brunt of the Mana Road Fire just as Native Hawaiians did during a large fire at Kahikinui, Maui in 2016 due to limited infrastructure. Large fires occur almost annually on Oahu’s Wai‘anae coast, impacting predominantly Native Hawaiian and Pacific Islander communities. On Guam, the CHamoru villages of the south, far from areas developed for tourism, face the largest threat of fire.

What is also unique about fire on Pacific Islands is how clearly it is linked to people. Lightning is rare on small islands, restricting “natural” fires to volcanic events. When Pacific Islands were first settled, the ignition switch was flipped on, as fire was used for many purposes like clearing land for farming, maintaining access to forested areas, and controlling pests.

Even now, nearly all fires on Pacific Islands are started by people, with ignitions tightly correlated with population. This also means that forest-dwelling plants and animals of Pacific Islands, many of which are found nowhere else, are poorly adapted to fire. However, it is important to understand that the negative impacts of fire on Pacific island ecosystems radically increased with colonization and militarization that brought in weeds, many of which promote fire.

Unlike continental forest fires, most Pacific Island fires burn grasslands, shrublands and savannas, which occupy upwards of 25 percent of island land areas. Pollen and charcoal deposits on Guam, Palau and Yap in Micronesia indicate that burning by people expanded this habitat as increases in fire activity and savanna vegetation coincided with human arrival.

Similar cultural burning occurred in Hawaii, however, modern grasslands and shrublands are dominated by nonnative species introduced over the last century for forage, erosion control, and landscaping. With large-scale abandonment of plantation and grazing lands within recent decades, these fire-prone weeds cover 1 million acres across the Hawaiian Islands and underlie a fourfold increase in annual area burned across the archipelago.

Finally, climate influences fire in the Pacific beyond just drought. Tropical grasses that fuel most fires accumulate large amounts of biomass when there’s ample rainfall. When the rains stop, these fuels cure and the risk of fire increases rapidly. Distinct wet and dry seasons on many islands set them up for annual fire cycles, even under “normal” rainfall. And El Niño-fueled drought affects the entire Pacific basin, leading to large fires even on perennially wet islands of eastern Micronesia. With climate change predicted to increase the intensity of both rainfall events and drought, these cycles will also intensify, making fire seasons more difficult to predict and fires more difficult to suppress.

Like much of the continental U.S., fire response in the Pacific is largely reactive. Most of the burden falls on municipal agencies geared for structure fires. The handful of wildfire-focused crews operate as reserve forces within forestry departments, which are broadly underfunded due, in part, to the lack of “forest industry” (i.e., logging).

Support from federal suppression agencies is also limited because of both distance and the absence of federal lands outside National Parks and military lands. As my firefighter colleagues consistently point out, “there’s no calling for reinforcements.”

The Mana Road Fire is yet another example of a fire incident extending beyond our capacity to control and echoes lessons from fires globally. Namely, we need proactive measures to reduce vulnerability long before fires ignite, and we need to be doing this at large scale.

The societal drivers of fire risk on Pacific Islands point toward relevant strategies. Education is critical for preventing human-caused ignitions and the prevalence of grass fires suggest tactics like grazing and the restoration of forests and farmland can reduce fuels and fire risk.

I find great hope in the resilience of Pacific island communities. There is growing interest in state- and non-profit sponsored neighborhood safety programs like Firewise. Other community-driven responses include the Hawaiian homesteaders supporting evacuation and suppression efforts at Pu‘ukapu and Kahikinui and reforestation and fire break projects led by villages on Yap, Palau, and Guam. Even these brief examples illustrate how our resilience to fire, and for that matter any impact from climate change, is rooted in thriving communities.

Building resilient landscapes will require transformational change in our current course of societal investment. For the Pacific, this means empowering community-grounded and Indigenous-led projects that revitalize and restore Pacific Island systems of knowledge, food production and land tenure that sustained island societies for millennia yet have been displaced by enduring legacies of colonialism. It also means improving other social infrastructure to strengthen communities like access to education, health care and housing. These needs are fundamental to moving beyond vulnerability and will enable us to redirect our energy and resources toward building and sustaining the ecosystems, food systems, and community relationships required to thrive through the fires and other climate-related challenges yet to come.

Clay Trauernicht, Ph.D., is an extension specialist in ecosystems and fire in the Department of Natural Resources and Environmental Management at the University of Hawaii at Mānoa. His research examines fire risk and ecosystem integrity in response to land use and climate. He’s also the lead for the Pacific Fire Exchange, a collaborative project making fire science useable by managers and the public and part of a national effort by the Joint Fire Science Program. Follow him on Twitter: @claytrau