Australia is sometimes called the “continent of fire” because the ecosystems of the world’s driest inhabited land have been shaped by constant burning. But even the continent of fire has never seen anything like the recent fires.
Bushfires have been raging in the southeastern states of New South Wales and Victoria for four months. More than 38,000 square miles, an area the size of South Carolina, have been burned. At least 28 people have died and about 2,000 homes in rural towns have been destroyed.
In Mallacoota, a coastal town in Victoria, 1,000 residents and tourists were rescued from the beach by the Australian navy as the fire spread. Even vineyards in the Adelaide Hills, which produce some of the country’s most prized and widely exported chardonnay and sauvignon blanc, have been destroyed. Adding to the chaos, the state government in South Australia has shot thousands of camels to protect Aboriginal communities besieged by herds of feral animals looking for water.
But it seems only the country’s climate-change-denying politicians are surprised. Australia’s meteorologists and fire chiefs have been predicting a record-breaking bushfire season for months. Weather watchers saw early in the year that Australia was facing a fire-inducing combination of natural rainfall cycles—most notably the fluctuating sea temperatures in the Indian Ocean that brought high temperatures and drought to southeastern Australia this year—and a highly unusual trend toward a hotter, drier climate. The ensuing fires have captured the world’s attention, largely because they are part of a pattern of increasingly intense wildfires from the Arctic to the Amazon.
Last year, Australia recorded its six hottest days on record, with temperatures reaching 122 degrees Fahrenheit.
Australia is one of the countries most affected by the pace of global warming. Last year, Australia experienced its highest temperature on record, 1.5 degrees Celsius (2.7 degrees Fahrenheit) above the late-20th century average and 2 degrees Celsius (3.6 degrees Fahrenheit) above the early-20th century average — double the global increase. The year also saw Australia’s six hottest days on record, with temperatures reaching a high of 49.9 degrees Celsius (122 degrees Fahrenheit).
Higher temperatures ensure vegetation dries out more quickly and more during droughts, creating an extreme risk of bushfires. And the drought has arrived. Australia’s average rainfall in 2019, at 10.9 inches, was 40 percent below the late-20th-century average and 12 percent below the previous lowest. The fires thus far surpassed Australia’s deadliest bushfire disaster in February 2009, when 173 people died but only 1,700 square miles burned.
As the country reacted in horror, meteorologists said, in effect, “We told you so.” The increased bushfire risk was predicted by Australian Bureau of Meteorology senior research scientist Chris Lucas, who warned 13 years ago that in southeastern Australia “the bushfire season will start a little earlier and end a little later, while being generally more intense. This effect… will be evident in 2020.” And it has been borne out.
In an article published last September with Sarah Harris of the Country Fire Authority in Victoria, Lucas reiterated that “human-caused climate change is the primary driver” of the increased fire risk. That analysis is at odds with the stance of national politicians, who in recent weeks have had to defend their notorious climate change scepticism, continued support for fossil fuels and failure to increase funding for fire services. In a radio interview in November, as the fires raged, Deputy Prime Minister Michael McCormack dismissed any link to climate change as “the babbling of some bright, enlightened, woke green people in the capital.”
Now, as Australians take to the streets to protest his policies, Prime Minister Scott Morrison has been forced to admit that the “greens” were right all along. “We’re living in longer, hotter, drier summers,” he said in a recent television interview. “That’s clearly driven by broader changes in the climate.”
Australia is used to bushfires. The country’s history is littered with the disasters they can cause: Black Friday in 1939, when 7,700 square miles burned and 71 people died; Black Tuesday in 1967, when 1,020 square miles burned and 62 people died; and Black Saturday in 2009. Much of the country’s ecosystem, including its iconic eucalypt forests, depends on regular fires,
Australia has more than 800 endemic eucalypt species, covering about three-quarters of the country’s forests. Most species thrive in fire-prone areas with poor soils. Their leaves are rich in flammable oils, which release seeds from woody capsules and create nutrient-rich ash where the seeds germinate.
But while they need fire, too much fire can burn them down. And this year’s hot, dry weather has caused fires to spread to forests with eucalypts that are adapted to wetter conditions, according to David Bowman, a wildfire ecologist at the University of Tasmania. Whether they can recover will be a key question for forest ecologists.
Equally uncertain is how wildlife is coping. Chris Dickman of the University of Sydney has ventured a guess — based on his previous assessment of animal densities conducted for the environmental group WWF Australia — that more than a billion mammals, reptiles and birds may have died, either burned, starved or eaten by predators like raptors and feral cats prowling the fire zones.
“The fires… will inevitably cause the extinction of some of Australia’s most iconic, fragile and beautiful animals,” one expert said.
But Kate Parr of the University of Liverpool, an expert in assessing the impact of bushfires on wildlife, said the estimate was based on sparse field data. What’s more, it assumes no survivors, which may be too pessimistic. “Australian animals have a long and impressive history of coexisting with fire,” said Dale Nimmo of Charles Sturt University in New South Wales. Some species have well-developed escape habits. Others hide in deep burrows and can hibernate temporarily until the fires are gone and food sources start to return.
Burned koalas have been a regular feature in television news reports about the fires. They may be individually vulnerable, but most koalas live outside the fire zone, said Ayesha Tulloch of the University of Sydney.
But the extreme nature of the fires could overwhelm the best response strategies. “The full impact of the fires… will undoubtedly result in the extinction of some of Australia’s most iconic, fragile and beautiful inhabitants,” said Ben Garrod, an evolutionary biologist at the University of East Anglia in the UK. Among those most at risk are endangered species that live primarily in the fire zones, including the eastern budgerigars; the long-legged potoroo, a rabbit-sized marsupial; and the silver-headed antechinus, a mouse-sized carnivorous marsupial that was only discovered in 2013.
Some foresters have blamed the ferocity of recent bushfires in part on the fact that there is too much wood to burn. Rod Keenan of the University of Melbourne, who receives funding from the forestry industry, blamed the large fires on the government’s reluctance to carry out controlled burning of dead wood early in the dry season. Forester Vic Jurskis, in a widely publicised open letter to the prime minister, blamed the reluctance on “green politics”.
But that accusation is false. Ecologists have long recognized that fires can be set to prevent fires. The United States learned the hard way in 1988, when Yellowstone burned, that preventing any fires is a recipe for storing fuel for future megafires. And Australia’s environmentalists know it too. In a policy paper drafted in 2017, long before the current fires, the Australian Greens called for “the ecologically appropriate and science-based use of fire” as “an effective and sustainable strategy for fuel reduction management to protect biodiversity and mitigate the impacts of bushfires.”
The story of Australia’s bushfires has captured international attention in part because it reflects a global pattern. The Amazon fires in August grabbed as many headlines as the Australian fires. Likewise, extreme wildfires in Siberia’s boreal forests have burned about 16,000 square miles, according to Greenpeace, with similar blazes in Alaska and western Canada. In 2018, California suffered the deadliest and most widespread wildfires, covering 3,000 square miles and causing more than 100 deaths. And in 2015, 10,000 square miles of Indonesian forest burned.
Researchers assert that climate change is increasing the risk. A review published this week by British and Australian researchers concluded that “human-caused warming has led to a global increase in the frequency and severity of wildfire weather, increasing the risk of wildfires.” A 2015 global study by Bowman and colleagues looked at trends in drought duration. They found that the average “fire season length” had increased by an alarming 19 percent between 1979 and 2013.
Yet despite the increased drought, the actual extent of fires worldwide, while still around 1.3 million square miles a year, has declined. One study found that it has dropped by 24 percent over the past two decades. This is partly due to a decline in deforestation in the Amazon after 2004 (a trend that has now reversed), and partly because farmers and ranchers are burning less to clear bush in Africa’s increasingly dense savanna grasslands. “As land use intensifies on savannas, fire is used less and less,” said Niels Andela of NASA’s Goddard Space Flight Center, who led the study.
One solution is to learn how indigenous peoples use fire to manage their land.
More and more wildfires and bushfires are occurring globally, either because of intentional deforestation for long-term farming — like in the Amazon and Indonesia — or because climate change has dramatically increased the risk of wildfires. And there is growing evidence that these climate-change-driven fires are becoming more intense and harder to control.
In short, there are fewer fires, but more wildfires.
So is there a way to mitigate the risks? One approach, many ecologists say, is to accept that not all fires are bad and learn from indigenous peoples’ land management practices with fire. In North America, “indigenous people burn a lot,” says Lee Klinger, a former employee of the National Center for Atmospheric Research (NCAR) and now an independent scientist who has studied fire regimes in California.
Before the Europeans arrived, traditional burning practices ensured that there were more fires in the forests of the West Coast than there are today, he said. “But they burned more frequently and therefore did less damage,” Klinger said. “There were ground fires, but not the canopy fires we see today.”
Australian researchers and Aboriginal communities say so. Traditional “burn” farming practices by Aboriginal people certainly change ecosystems by burning small fires to clear land for farming. But many researchers argue that these effects can be beneficial. These “cool burns” maintain open grasslands, expand the range of fire-adapted species, and often increase local biodiversity by creating a mosaic of different habitats. “Aboriginal burning is important for maintaining habitat for small mammals,” says Bowman, who coined the term “pyrodiversity” to describe the biodiversity benefits of the practice.
The question now is whether even such clever fire management techniques can stop the blazes. As climate change dries out the bush, and temperatures soar to levels far beyond what local ecosystems can handle, the old ways may no longer work.
This question is particularly relevant for Australia. Most climate models predict that “Australia will warm faster than the rest of the world,” says Kevin Hennessy, a climate scientist at CSIRO, Australia’s national research agency. Global warming could also cause further declines in rainfall in southern Australia, leading to longer droughts and more days of severe bushfire risk.
But Australia’s current fires increasingly look like a harbinger of new megafires elsewhere. During a period of intense warming in the American West over the past half-century, the number of wildfires covering more than 1.5 square miles has increased fivefold — a trend that researchers link to higher temperatures and longer droughts, and is expected to continue.
In Mediterranean Europe, where wildfires are a growing summer threat from Portugal to Greece, researchers predict a 40 to 100 percent increase, largely dependent on rising temperatures. There is little doubt that wildfires will also become more frequent in boreal forests in the far north as the Arctic warms. Most recently,
a paper published last week in the journal Science argues that the deadly combination of deforestation and climate change will double the area burned annually in the southern Amazon by 2050. Paulo Brando of the Woods Hole Research Center in Massachusetts titled his paper: “The Gathering Firestorm.”