In 2016, the closure of Hawaii’s last sugar cane plantation symbolized the end of sugar’s dominance in the state’s economy. However, it also highlighted the rapid spread of highly flammable, nonnative grasses on abandoned lands where crops once thrived. Grasses such as guinea grass, molasses grass, and buffel grass, which originated from Africa, now cover almost a quarter of Hawaii’s land area. These grasses, which grow quickly and withstand drought, have contributed to the increase in wildfires across the state.
Melissa Chimera, who coordinates the Pacific Fire Exchange, a project sharing fire science among Pacific island governments, explains that these grasses are highly aggressive, fast-growing, and highly flammable. This combination leads to larger and more destructive fires. The recent fire in Maui, which claimed 93 lives, has raised concerns about the rising vulnerability of tropical places like Hawaii to wildfires.
While Hawaii has always had arid areas and drier grasslands, recent years have seen a decline in rainfall, thinner cloud cover, and drought due to rising temperatures. This has made the state more prone to wildfires. A hazard mitigation plan prepared for Maui County in 2020 identified West Maui as the area with the highest annual probability for wildfires. The plan also noted that the nonnative grasses, particularly on former plantation lands, contribute to the increased risk of large fires. Clay Trauernicht, a wildfire expert from the University of Hawaii at Manoa, emphasizes that these grasses can cause a manageable fire to escalate rapidly in size.
The spread of nonnative grasses is further exacerbated by nonnative trees, such as mesquite and wattles, as well as conifers planted for erosion control. These trees add to the wildfire risks in Hawaii. Efforts to mitigate the risks include building firebreaks, introducing fire-resistant vegetation, and managing the grasses through grazing livestock. However, implementing these measures can be expensive and logistically challenging.
The need for proactive wildfire mitigation efforts in Hawaii has been a topic of debate for years. Hawaii’s diverse terrain adds complexity to firefighting operations, and competition for federal wildfire grants with other Western states poses challenges. Human activities, like campfires and sparks from vehicles, contribute to the ignition of fires. Additionally, the state’s acute housing shortage, particularly the large homeless population, increases the risk of ignitions.
The hazard mitigation plan for Maui County also warns that climate change is exacerbating Hawaii’s vulnerability to wildfires. As temperatures rise and drought conditions become more frequent and intense, the frequency of wildfires could increase. West Maui, in particular, is identified as a vulnerable area due to a high percentage of non-English speakers and households without vehicles, making it harder for residents to receive information and evacuate during a fire.
In conclusion, the spread of highly flammable, nonnative grasses combined with climate change poses significant wildfire risks in Hawaii. Efforts to mitigate these risks are challenging due to the state’s diverse terrain, competition for funding, and human activities. As Hawaii continues to face the threat of wildfires, proactive measures such as building firebreaks and managing vegetation are crucial for reducing the impact of these fires on communities.