A dangerous combination of conditions appears to have converged A forest fire on a path of destruction Hawaii is particularly damaging, including high winds, low humidity and dry vegetation.
Experts say climate change is increasing the likelihood of extreme weather events What’s playing on the island of MauiDozens of people have been killed and a The historic tourist town was destroyed.
“That leads to these unpredictable or unexpected combinations that we’re seeing now,” said Kelsey Cobbs-Kerbitz, a postdoctoral researcher at the University of British Columbia’s Faculty of Forestry.
Here’s a look at Maui fires and what’s behind them:
What fuels them?
According to meteorologists, the large differences in air pressure created unusually strong trade winds that fueled the destructive flames.
Trade winds are a natural feature of Hawaii’s climate. They occur when air moves from a high pressure system north of Hawaii — known as the North Pacific High — to an area of ​​low pressure on the equator south of the state.
But Hurricane Dora, which passed south of the islands this week, intensified the low-pressure system and widened the difference in air pressure, creating “unusually strong trade winds,” said Genki Kino, a meteorologist with the National Weather Service office in Honolulu. .
Pao-Shin Chu, Hawaii’s state climatologist, said he was caught when Torra struck from about 500 miles (800 kilometers) away.
“Hurricane Dora is far away from Hawaii, but this fire event is still here. So it’s something we didn’t expect,” he said.
The combination of strong winds, low humidity and an abundance of easily flammable dry vegetation can increase the risk of wildfires, even on a tropical island like Maui.
“When you have those conditions at the same time, the National Weather Service often calls them ‘red flag conditions,'” said Erica Fleishman, director of the Oregon Climate Change Research Institute at Oregon State University.
How climate change plays a role
“Climate change is increasing the desiccation of vegetation in many parts of the world, largely because temperatures are warming,” Fleischmann said. “Even if you have the same amount of rain, the higher the temperature, the faster things will dry out.”
Clay Trauernicht, a fire scientist at the University of Hawaii, said the wet season will encourage plants like guinea grass, an invasive species found in parts of Maui that can grow up to 10 feet (3 meters) tall. When it dries, it creates a tinderbox ripe for wildfires.
“These grasslands accumulate fuel very quickly,” Traurnicht said. “In hotter conditions and drier conditions, with variable rainfall, this can exacerbate the problem.”
A strong storm
Climate change not only increases fire risk by increasing temperatures, but also makes stronger hurricanes more likely. In turn, those storms can fuel strong wind events like the one behind the Maui fire.
This is on top of other threats exacerbated by climate change.
“There is an increasing trend in the intensity of hurricanes around the world because warm air contains more water,” Fleishman said. “Also, sea levels are rising globally, so you tend to get more severe flooding from storm surge when a hurricane makes landfall.”
While climate change cannot be directly attributed to single events, experts say, the impact extreme weather has on communities is undeniable.
“These kinds of climate change-related disasters are really beyond the scope of what we’re used to dealing with,” said UBC’s Copes-Gerbitz. “These kinds of multiple, interactive challenges can really lead to a disaster.”
___
Claire Rush is a corps member of the Associated Press/Report for America Statehouse News Initiative. Report for America is a nonprofit national service program that puts journalists in local newsrooms to report on hidden issues. Follow her @ClaireArush.
