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作者:探索 来源:焦點 浏览: 【大中小】 发布时间:2024-11-10 08:17:49 评论数:
Back in early November, David Bowman had a bad feeling about Australia's thriving wildfires.
The ingredients for bushfire hell had come together. The forests were exceptionally dry. There was no hint of meaningful rain. Winds howled through the country. And it was getting hotter. Eventually, Australia broke its record for its hottest day ever — two days in a row.
"I said 'this is unprecedented'," recalled Bowman, a professor of pyrogeography and fire science at the University of Tasmania. "The whole system was set up to burn."
It has.
Fires have burned over three million acres of Eastern Australia bushland, including the 1.2-million-acre Gospers Mountain megafire northwest of Sydney, labeled "out of control" by the region's fire agency, the New South Wales (NSW) Rural Fire Service. That's nearly the size of Grand Canyon National Park, and larger than Rhode Island. The Syndey Morning Herald called Gospers a "monster" fire, and notes it's now the largest forest fire to start from a single ignition point in Australian history (there have been larger grass fires).
Australia always burns in the summer. But not like this. "With these conditions, any fire can get big and out of control," said Christine Wiedinmyer, the associate director for science at the University of Colorado Boulder's Cooperative Institute for Research in Environmental Science. "These fires are gigantic."
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And the blaze isn't going away anytime soon. The fire could burn for another six weeks, or longer, said Bowman.
"There's no end in sight," he said. "There’s plenty of action left in this fire season. This is historic."
From afar, the lengthy, historic blazes have smoked out the nation's most populous city, Sydney, at times creating air pollution levels 11 times that of the "hazardous" threshold. The fires are difficult for many Australians to comprehend or describe.
"The vocabulary is exhausted," said Bowman. "Words are exhausted. Emotions are exhausted."
"Words are exhausted."
Bowman said the fires have essentially ringed the greater Sydney area. In communities along the fringe of the Gospers and other fires, the National Rural Service is fighting to protect lives and property from persistent flames. Some 829 homes have burned, but 7,310 have been saved.
"There’s going to be no Christmas for [firefighters]," he said.
Like all wildfires, the Gospers blaze and other fires are the product of both weather and climate — and Australia's climate has warmed significantly since 1950, according to the Australian government's Department of Environment. That means more fire weather, and more parched trees. Fire conditions depend on wind, dryness of vegetation, air temperature, and humidity. In particular, these Australian blazes have been getting a boost from exceptional heat and dryness. Then, add some wind, and all you need is a spark. The same thing happened in California last summer.
"It's the dryness," said Bowman. "The fuels [vegetation] are incredibly dry and burning really efficiently."
Australia's national science research agency, CSIRO, would not comment on the Gospers Mountain Fire, but did refer Mashable to its research on Australian wildfires. "The frequency and severity of fire weather has increased over recent decades," the agency says. "We predict many regions will see a significant increase in the highest levels of fire danger in the year [sic] ahead."
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Australian fire weather, particularly in eastern Australia, has been extreme this year. "The continent just got hotter and hotter and hotter and hotter and hotter," said Bowman.
What's more, rainfall has been low in Australia this year, thanks to shifts in a climate cycle called the Indian Ocean Dipole, resulting in fewer clouds and storms forming near Australia. This means drought. And drought plus extreme heat means forests and grasslands are turned to kindling.
As is commonly the case, climate change boosts the odds for extreme weather or conditions, be it floods, fires, or the extreme melting of ice sheets.
While most Australians aren't literally in the path of Australia's flames, between one-third to a half of the Australian population can't escape its consequences, namely smoke saturated with tiny particles from burnt vegetation and homes, said Bowman.
SEE ALSO:The oceans absorbed an unfathomable amount of heat this decadeThese particles, called PM 2.5 (particulate matter smaller than 2.5 microns in size), are the type of air pollution we see from fires, explained Boulder's Wiedinmyer. This pollution shrouded Sydney's famous opera house earlier this month. "It's the air pollution we know most impacts our health," Wiedinmyer said.
It's terrible for breathing. The fine particulate matter is often many times thinner than a strand of human hair. Both U.S. government and university researchers have repeatedly shown that breathing this stuff is bad for your heart. It's linked to an acceleration of plaque build-up in blood vessels.
Australians can anticipate more terrible to hazardous air, saturated with remnants of burnt forests. The nation's Bureau of Meteorology expects "to see a continuation of the warmer and drier than average conditions experienced throughout spring."
The smoke is horrid. "It's tarnishing the Australian tourist brand," said Bowman. "There’s an enormous amount of social anxiety, grief, confusion, and despair."
"People are seeing in real-time the places they love distort in front of them," he said.