Maui fires not just due to climate change but a ‘compound disaster’
As scientists weigh the influence climate change may have had in fueling Hawaiis wildfires , there isnt one standout factor they point to. Rising temperatures likely contributed to the severity of the blaze in several ways. But global warming could not have driven the fires by itself. Maui is facing a compound disaster , where many different agents acted together to make the fires so horrific. As human influences on the climate and environment grow, the risk of these disasters is escalating. Hawaii utility faces scrutiny for not cutting power to reduce fire risks Recent floods in China , fires in Greece and deadly heat in the Southwest U.S. are other recent examples of how extreme weather, human-caused climate change and changes to the local environment can converge in devastating fashion. If you add together a whole bunch of influences, thats how you get a disaster, said Jeff Masters, a meteorologist for Yale Climate Connections. No one thing makes it happen. The links between human-caused climate change and fires are well-established. Global warming means plants can more easily dry out, because warmer air hastens the evaporation of water. As the air sucks more moisture from the land, fire risks are increasing. Hawaii is, on average, two degrees warmer than it was in 1950, according to state climate data. Scientists said that likely provides the strongest connection between humans fossil fuel consumption, which emits greenhouse gases that warm the planet, and the likelihood of fires in Hawaii and elsewhere. In photos: The scene as deadly wildfires devastate parts of Hawaii Rising temperatures have also intensified the heat that has baked the Southwest this summer and which sent hot, dry air toward Hawaii this week. And climate change is helping to strengthen hurricanes like the one that passed south of the islands this week , probably increasing the strength of winds that fanned the flames. But scientists have also prominently mentioned the role of non-climate influences in the intensity of the firestorm, such as the introduction of highly combustible nonnative plants, as well as weather patterns that happen naturally. What we know about the cause of the Maui wildfires Among factors that made the fire so destructive severe winds and ongoing drought the influence of climate change appears indirect, at best. As wind sent fires spreading out of control Tuesday, many meteorologists pointed out that Hawaii found itself between a strong area of high pressure over the North Pacific and Hurricane Dora, a cyclone that rapidly intensified into a major Category 4 storm. That pressure difference meant Hawaii was in the middle of winds flowing intensely from high pressure to low, gusting over the islands like air being released from a balloon at more than 80 mph in some spots. Research has shown more tropical cyclones have rapidly intensified in recent decades, and that those rates of intensification have accelerated. Warmer temperatures provide more energy for storms. But some immediate analyses of the winds observed in Hawaii have found Doras presence may have only increased the gusts speed by about 5 mph, Masters said. The high pressure aided by a flow of hot, dry air from the Southwestern U.S. into the Pacific could have been enough to stir damaging winds on its own. The hurricane and its intensity were certainly not the main effect fueling the fires, Masters said, though its presence could have contributed to the disaster. After five hours in ocean, Maui fire survivor is blessed to be alive As for the drought conditions that covered more than a third of Maui County, where the most destructive fires burned, there is no direct sign that they are the product of climate change, said Abby Frazier, an affiliate faculty member at the University of Hawaii now based at Clark University in Massachusetts. While there is a long-term trend of declining precipitation in Hawaii, there isnt enough evidence to suggest that is the product of anything besides normal climate patterns and fluctuations in the Pacific, she said. Precipitation patterns there are heavily influenced by El Nino, which returned in June, and by a longer-term pattern known as the Pacific Decadal Oscillation. El Nino is known for bringing drier winters, but its arrival doesnt explain the current conditions, Frazier said. In the summer, it can bring more precipitation than normal because of increased tropical cyclone activity, she said. We cant officially say its climate change thats causing all this drying, Frazier said. Natural variability is just so strong in Hawaii. That is not to say human activity didnt directly contribute to the fires in ways that dont involve the climate. They are increasingly spreading by burning invasive and fire-prone grasses brought to the islands for ornamental use or for cattle grazing. As agricultural activity has declined on the islands, the grasses have spread across fields that were once regularly watered and maintained, said Alison Nugent, an associate atmospheric scientist at the University of Hawaiis Water Resources Research Center. Over the last few decades those managed agriculture lands have progressively become more and more unmanaged, Nugent said. Theres grassland right next to very expensive houses. The wildfire risks that introduces demonstrate that its more than climate change, Masters said. Humans are messing with the system. As long as that continues, he said, We should expect these sorts of catastrophes to increase. These maps show where wildfires are burning in Hawaii Clay Trauernicht, a fire researcher at the University of Hawaii, said he and others concerned about wildfire risks have for years been working to raise awareness about the importance of better managing the grasses and taking other efforts to harden homes. He said he hopes the devastation on Maui is enough to spur action so that the fires burden isnt left solely to firefighters. We dont have to be at the mercy of these weather events, but the way were operating right now, we are, Trauernicht said. While climate change is a global problem, the grasses are a local one. This is a thing we can manage. Whats happening: The official death toll from Mauis wildfires has risen over 110 , with the number expected to increase. Officials have also released a list of 388 people who are still unaccounted for after wildfires. How did the fires start? Officials have not announced a cause, though Hawaiian Electric denies sparking the deadly Maui blaze . The spread of flammable nonnative grasses combined with hurricane-stoked winds could have been factors alongside the indirect influence of climate change . What areas have been impacted? Fires burned across multiple Hawaiian islands these maps show where . The town of Lahaina on the island of Maui suffered widespread damage, and historical landmarks across the island were damaged . These photos show the extent of the blaze . Can I help? Thousands of residents and visitors were forced to evacuate. Many organizations are accepting donations to assist those affected by the wildfires.