What caused the Maui wildfires?

LAHAINA, Hawaii — A dangerous mix of conditions seem to have come together to create Wildfires burn path of destruction in Hawaii particularly damaging, including high winds, low humidity, and dry vegetation.

Experts also say climate change is increasing the likelihood of more extreme weather events like what’s going on on the island of Mauiwhere at least 6 people were killed and a historic tourist town was badly damaged.

“This leads to the unpredictable or unpredictable combinations we’re seeing today,” said Kelsey Copes-Gerbitz, a postdoctoral researcher in the University of British Columbia’s forestry department. and is driving this extreme fire weather. “What… these catastrophic wildfire disasters reveal is that nowhere is immune to this problem.”

Here’s a look at the Maui fires and what’s behind them:

According to meteorologists, the huge difference in air pressure created unusually strong trade winds that fanned the destructive flames.

Trade winds are a normal feature of Hawaii’s climate. They are caused when air moves from a high-pressure system pressure north of Hawaii – known as the North Pacific High – to an area of ​​low pressure at the equator, in the southern part of the state.

But Cyclone Dora, which passed south of the archipelago this week, is exacerbating the low-pressure system and increasing the air pressure differential to create “unusually strong trade winds,” said Genki Kino, a co-author of the study. National Weather Service office in Honolulu, said. .

Hawaii state climatologist Pao-Shin Chu said he was caught off guard by Dora’s impact from about 500 miles (800 km) away.

“Hurricane Dora is a long way from Hawaii, but you can still have a fire here. So this is something we don’t expect to see,” he said.

Strong winds, combined with low humidity and lots of dry, combustible vegetation, can increase the risk of wildfires, even on a tropical island like Maui.

“If you have all of those conditions at once, that’s usually what the National Weather Service calls ‘,” said Erica Fleishman, director of the Oregon Climate Change Research Institute at Oregon State University. red alert status’.

RELATED: Maui wildfire kills at least 6, damages more than 270 structures as it sweeps through historic town

“Climate change in many parts of the world is increasing the dryness of vegetation, largely due to hotter temperatures,” says Fleishman. “Even if you get the same amount of rain, if you have higher temperatures, things will dry faster.”

Clay Trauernicht, a fire scientist at the University of Hawaii, says the rainy season can spur plants like Guinea grass, an invasive, non-native species found throughout parts of Maui, to flourish. fast up to 6 inches (15 cm) per day and reach up to 10 feet (3 meters) tall. As it dries, it creates a bushfire-ready igniter.

“These grasslands accumulate fuel very quickly,” says Trauernicht. “In hotter and drier conditions, with variable rainfall, it will only exacerbate the problem.”

Climate change not only increases fire risk by increasing temperatures, but it also makes stronger storms more likely. In turn, those storms can spur stronger wind events like the one behind the Maui fires.

That’s on top of other threats made worse by climate change.

“The intensity of hurricanes worldwide is trending up, in part because warmer air contains more water,” says Fleishman. Also, sea levels are rising worldwide, so you tend to experience more severe flooding from high tides when a storm makes landfall.

While it’s impossible to say climate change is a direct cause of single events, experts say the impact of extreme weather on communities is undeniable.

“These kinds of climate change-related disasters are really outside the scope of what we are used to dealing with,” said UBC’s Copes-Gerbitz. “It is these kinds of diverse interactive challenges that really lead to a disaster.”

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