2023-08-10 01:12:33
A dangerous combination of conditions, such as high winds, low humidity and dry vegetation, appear to have contributed to making the wildfires raging in Hawaii particularly damaging.
Experts also say climate change is increasing the odds of extreme weather events like the one unfolding on the island of Maui, where at least six people have died and a historic resort town was devastated.
“It’s leading to these unpredictable or unexpected combinations that we’re seeing right now that are driving these extreme fire-friendly weather conditions,” said Kelsey Copes-Gerbitz, a postdoctoral researcher at the University of British Columbia’s School of Forestry. “What these … catastrophic wildfires are revealing is that no place is immune from the problem.”
Here’s a look at the fires plaguing Maui and what caused them:
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WHAT FANS THESE FIRES?
The large differences in atmospheric pressure caused strong trade winds that fanned the flames, according to meteorologists.
Trade winds are a regular feature of Hawaiian weather. They are produced when air moves from the high pressure system north of Hawaii to the low pressure system at the equator in the south of the state.
But Hurricane Dora, which passed south of the islands this week, is exacerbating the low-pressure system and increasing the atmospheric pressure difference to create “unusually strong trade winds,” said Genki Kino, a meteorologist with the National Weather Service office. in Honolulu.
Strong winds, coupled with low humidity and an abundance of dry vegetation that burns easily, can add to the danger, even on a tropical island like Maui.
“If you have all of these conditions at the same time, you have what the National Weather Service calls a ‘red flag,’” said Erica Fleishman, director of the Oregon Climate Change Research Institute at Oregon State University.
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HOW DOES CLIMATE CHANGE PLAY A ROLE?
“In many parts of the world, climate change is increasing the dryness of vegetation, largely because temperatures are higher,” Fleishman said. “Even if you have the same amount of precipitation, if you have higher temperatures, things dry out faster.”
Clay Trauernicht, a fire scientist at the University of Hawaii, said the wet season can encourage plants like guinea grass, an invasive species found in some parts of Maui, to grow up to 6 inches a day. day and reach up to 3 meters (10 feet) in height. When it dries, it creates a tinderbox capable of spreading forest fires.
“These grasslands accumulate fuels very quickly,” Trauernicht said. “In hotter, more arid conditions, with variable rainfall, the problem will only get bigger.”
STRONGER HURRICANES
Climate change not only increases the risk of fires by raising temperatures, but also increases the chances of stronger hurricanes. In turn, those storms can unleash higher-magnitude winds, such as those responsible for the fires on Maui.
That adds to the other threats that climate change has exacerbated.
“Hurricane intensity tends to increase around the world, in part because warmer air holds more water,” Fleishman explained. “In addition, sea levels are rising around the world, so more severe flooding from storm surge tends to occur when a hurricane makes landfall.”
Although climate change cannot be said to directly cause unique events, according to experts, the impact of extreme weather conditions on communities is undeniable.
“These types of climate change-related catastrophes are beyond what we are used to dealing with,” Copes-Gerbitz said. “It’s these kinds of multiple, interactive challenges that really lead to disaster.”
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