Australia's
unprecedented wildfires are supercharged thanks to climate change, the type of
trees catching fire and weather, experts say.
And these fires are so extreme that
they are triggering their own thunderstorms.
Here are a few questions and
answers about the science behind the Australian wildfires that so far have
burned about 5 million hectares (12.35 million acres), killing at least 17
people and destroying more than 1,400 homes.
"They are basically just in a
horrific convergence of events," said Stanford University environmental
studies director Chris Field, who chaired an international scientific report on
climate change and extreme events. He said this is one of the worst, if not the
worst, climate change extreme events he's seen.
"There is something just
intrinsically terrifying about these big wildfires. They go on for so long, the
sense of hopelessness that they instill," Field said. "The wildfires
are kind of the iconic representation of climate change impacts."
What is causing the fires?
Each year there is a fire season during the Australian summer, with hot, dry weather making it easy for blazes to start and spread.
Natural causes are to blame most of the time, like lightning strikes in drought-affected forests. Dry lightning was responsible for starting a number of fires in Victoria's East Gippsland region in late December, which then traveled more than 20 kilometers (12.4 miles) in just five hours, according to state agency Victoria Emergency.
Humans can also be to blame. NSW police have charged at least 24 people with deliberately starting bushfires, and have taken legal action against 183 people for fire-related offenses since November, according to a police statement.
Why are the fires so bad?
Fire season in Australia is always dangerous -- the 2009 Black Saturday fires killed 173 people in Victoria, making it the deadliest bushfire disaster on record. But conditions have been unusually severe this year, fanning the flames and making firefighting conditions particularly difficult.
Australia is experiencing one of its worst droughts in decades -- the country's Bureau of Meteorology said in December that last spring was the driest on record. Meanwhile, a heatwave in December broke the record for highest nationwide average temperature, with some places sweltering under temperatures well above 40 degrees Celsius (about 113-120 degrees Fahrenheit).Strong winds have also made the fires and smoke spread more rapidly, and have led to fatalities -- a 28-year-old volunteer firefighter died in NSW in December after his truck rolled over in high winds.
Fire season in Australia is always dangerous -- the 2009 Black Saturday fires killed 173 people in Victoria, making it the deadliest bushfire disaster on record. But conditions have been unusually severe this year, fanning the flames and making firefighting conditions particularly difficult.
Australia is experiencing one of its worst droughts in decades -- the country's Bureau of Meteorology said in December that last spring was the driest on record. Meanwhile, a heatwave in December broke the record for highest nationwide average temperature, with some places sweltering under temperatures well above 40 degrees Celsius (about 113-120 degrees Fahrenheit).Strong winds have also made the fires and smoke spread more rapidly, and have led to fatalities -- a 28-year-old volunteer firefighter died in NSW in December after his truck rolled over in high winds.
Experts say climate change has worsened the scope and impact of natural disasters like fires and floods -- weather conditions are growing more extreme, and for years, the fires have been starting earlier in the season and spreading with greater intensity.
Several high-ranking emergency service officials, including the former commissioner of the NSW Fire and Rescue Department, sent letters to Prime Minister Scott Morrison in 2019 warning of the impact of the climate crisis on Australia.
How many animals have died?
About half a billion animals have been affected by the fires across NSW, with millions likely dead -- and that's a conservative estimate. That number of total animals affected could be as high as one billion nationwide, according to ecologists from the University of Sydney.
The figures for NSW include birds, reptiles, and mammals, except bats. It also excludes insects and frogs, so the real sum is almost certain to be higher, the ecologists said.
Almost a third of koalas in NSW may have been killed in the fires, and a third of their habitat has been destroyed, said Federal Environment Minister Sussan Ley.
Some species, like koalas, aren't in any immediate danger of extinction because they are spread out across the country, said the university ecologists. But others that live in more niche environments with lower populations, including certain types of frogs and birds, could be wiped out entirely if their habitats are hit by the fires.
These are pretty good estimates based on previous research on population density -- but until the fires stop, researchers have no way of surveying just how extensive the damage is, and exactly how many animals have died.
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