n the air above Fish River Station
In the 1800s, when ranchers moved into northern Australia, they largely put a stop to the age-old Aboriginal tradition of setting fire to the savannas. The unintended side effect has been the buildup of dry grass, which has fueled increasingly larger and more intense wildfires. From 2000 to 2009, wildfires burned as much as 69 percent of Fish River Station annually and at an intensity severe enough to kill trees, degrade habitats and emit an average 24,000
metric tons of carbon each year—nearly twice the levels scientists estimate were released when the land had been managed by traditional methods.
To halt that off-kilter cycle, scientists have turned to the past. The idea is simple: Light small fires in favorable conditions before unmanageable wildfires have a chance to start. It’s a strategy that could help restore the ecology of parts of northern Australia—home to the world’s largest intact tropical savanna—while also reviving a cultural practice that was once integral to the Aboriginal way of life here.
But it’s a tall order. Lighting fires on a vast tract of land in one of the most remote corners of the continent requires hard work, money and equipment: helicopters and incendiary machines, fuel and torches. Yet if the plan works here, researchers say, it might be a model for curbing massive wildfires and their associated carbon emissions elsewhere in Australia and, potentially, around the world.
Charcoal records and other scientific evidence show that for at least 50,000 years, the nomadic Aboriginal peoples of Australia used fire as a tool to shape their surroundings. As they moved across the continent, they lit small fires to aid in the hunting of kangaroos and monitor lizards. Their practice is known as fire-stick farming: Burning releases a pulse of nutrients and encourages the growth of green grass shoots, which in turn attract prey. They also used fire to suppress insect pests, to clear paths and to perform ceremonies, such as the traditional smoking ceremony, in which plants are slowly burned to ward off bad spirits.
“In Australia, people are a part of the ecosystem and have been for tens of thousands of years,” says Ansell. He and Geoff Lipsett-Moore, a biologist who directs The Nature Conservancy’s northern Australia program, worked together to set up the modern burn program at Fish River.
Though the north’s sparse population means that few humans are in the path of such fires—the deadly wildfires that have made headlines in recent decades were in the more-populated southeast—big blazes take a toll on biodiversity in the savanna, says James Fitzsimons, the Conservancy’s director of conservation in Australia.
“Wildfires are one of the big drivers of declines of birds and mammals in the north,” he says. “So reinstating a more traditional fire regime is important for biodiversity.”
For years, Fish River Station struggled to make a profit as a cattle ranch, stretching over hundreds of thousands of acres of savanna, woodlands, wetlands and rainforest. Its fate changed abruptly in 2010, when the Indigenous Land Corporation (ILC), an Australian agency that helps buy land to return to its traditional owners, purchased the ranch with assistance from the Conservancy, the Pew Charitable Trust’s environment group, Greening Australia and the National Reserve System. The ILC, the Conservancy and another Australian agency called the Northern Land Council are now working on the legal arrangements that will transfer ownership of the land to members of the Larbarganyin, Wagiman, Malak Malak and Kamu groups—on the condition that the land remain conserved.
Since 2010, members of the Aboriginal groups have returned and begun holding ceremonies, taking part in ecological surveys. The ILC and the Conservancy have been working with them to restore some Aboriginal fire traditions, particularly setting small prescribed burns.
Setting fire to fight fire may seem counterintuitive, says Blane Heumann, a fire ecologist and the Conservancy’s director of fire management. But it’s not quite as contradictory as it sounds. “If your problem is too much hot fire,” he says, “then your solution should be some good fire.”
By “good” he means smaller fires set when temperatures are low and humidity is relatively high. “They burn with less intensity,” he says. “Their flames are anywhere from 6 inches to 2 or 3 feet in height—something that is fairly manageable with simple tools.” Bad fires—in Fish River’s case, late dry-season wildfires—can have flames 10 to 20 feet high and are difficult to control, Heumann says. “You have to back away.”
Fire behavior is well-established. “More fuel makes more fire. Hotter makes more fire. Drier makes more fire,” he says. Whereas good fires tend to stay low, big fires emit more carbon as flames overtake mature trees.
The result is smaller, more frequent, less intense fires. Fewer trees are charred and killed, less land is severely damaged, and less carbon is pumped into the air.
Since the Fish River fire program was set in motion nearly four years ago, the project has reduced the amount of land burned by late-season wildfires from 56 percent in 2009 to 5 percent or less annually, and decreased carbon emissions by nearly 26,000 metric tons over the course of 2011 and 2012. The ILC and the Conservancy, led locally by Ansell and Lipsett-Moore, have worked with traditional owners to plan where and how to burn the land. Since 2011, the ILC has hired 25 indigenous workers to manage the property, including four fire rangers who do the bulk of the burning.
The fires that sweep through northern Australia’s savanna—one of the least populated areas on the planet—produce from 3 to 5 percent of the country’s greenhouse-gas emissions, according to Lindsay Hutley, a biologist at Australia’s Charles Darwin University.
As part of its effort to fight climate change, the Australian government in 2012 implemented a policy to make major polluters in the energy and industrial sectors pay a fixed tax for each ton of carbon emitted, effectively discouraging increased emissions. Companies looking to pay less tax can offset some of their emissions by purchasing “carbon credits” from programs generating certified reductions in emissions—such as those at Fish River. The property earned more than US$450,000 in 2013 after it sold its 2011 and 2012 carbon credits for nearly $20 a ton to an Asian-Pacific energy company. Those earnings are being used to pay for the burning program, as well as to support other conservation work at Fish River. However, the future of this funding mechanism is up in the air, because the country’s new prime minister recently proposed repealing the carbon tax.
Still, the work isn’t done. Lipsett-Moore has his eye set farther afield on another indigenous land area to the west of Fish River, in the Kimberley region. Last year, the Conservancy helped set up four new indigenous protected areas in this region, totaling more than 10.3 million acres—roughly the size of Massachusetts and New Hampshire combined. The lands have been added to Australia’s National Reserve System, and the Conservancy has helped develop the conservation management plans that will guide their use. The Conservancy and the Kimberley Land Council have begun fire programs there similar to Fish River’s. Across the northern Australian savanna, the total reduction in carbon emissions could be significant, says Lipsett-Moore.
And Heumann sees potential at an even larger scale around the world. “Take all these landscapes that are like Fish River and gain control of the fire regime,” he says. “You could take a big bite out of carbon emissions from open burning.” •