It is hard to believe that ticking a box and paying an extra fee when you buy an airline ticket can make your flight carbon neutral.
But some airlines are using that money to buy carbon credits from Indigenous ranger groups who then fund bushfire management in northern Australia.
Researchers and rangers are producing peer-reviewed science that shows Indigenous fire management practices can prevent greenhouse gas emissions as well as protect native plants and animals.
Cameron Yates from the Charles Darwin University Centre for Bushfire Research says more than 10 million tonnes of carbon have already been cut from global emissions over the past decade by rangers preventing hot wild fires in tropical savannas.
"There's been big changes in northern Australia since these projects have started," he said.
"We commonly had very large fires burn in excess of 10,000 kilometres squared.
"In areas that have [fire management] projects, you don't see those sorts of massive fires anymore."
Fire in the desert
New research is almost complete that will expand the program from the tropical savanna into northern deserts.
Despite the common perception that deserts are dusty places where nothing grows, Ngurrara head ranger Justin Andrews says his Walmajarri country in the Great Sandy Desert can experience monsoonal floods driving growth of dense vegetation.
"It's sand dunes, but it's all scrub and spinifex," Mr Andrews said.
"In the wet season the rain is really heavy down there. The water spot that we call a jila, all fills up, and it's like paradise."
But the dry season primes the vegetation for fire, and with many Walmajarri people now living in towns and communities, millennia of traditionally burning small patches of desert vegetation gave way to hot fires that burnt across the landscape.
Jarrad Holmes is an environmental scientist who has worked with Indigenous land managers coordinating the research behind carbon emissions reduction through fire management, and he says carbon credits can fund the work of ranger groups.
"Mostly by reinstating the traditional fire practices, so getting out more in the cooler times of the year when it's not too windy," he said.
"Those fires are less intense, smaller in size generally … so using fire to reduce the amount of fire overall."
Hot, hard science
The idea that traditional Indigenous fire practices can reduce climate-changing emissions may seem like a warm and fuzzy fantasy to sceptics, but it is based on hard science, with data painstakingly collected in harsh conditions.
"It is all trackable from space from satellites," Mr Holmes said.
"It can be measured and there's been more than 20 years of research to collect the data to work out how many tonnes of smoke are going up into the air."
With the help of the Ngurrara rangers, the Bushfire Research Centre is able to measure the different carbon emissions from traditional burning and wild fires.
The data that measures exactly how much carbon is released in the northern deserts is soon to be published in peer-reviewed journals, ahead of new areas being added to the carbon trading scheme.
"We set up these plots and measure, cut and weigh all the grass," Mr Yates said.
"We pick up all the sticks … count the shrubs and the trees, and then we burn it.
"We've done it in the early dry season and we've done it in the late dry season, and we can see how much more of that fuel is consumed."
The science becomes quite complicated in terms of the way different fires produce different types of gases that contribute more or less to climate change.
Dutch scientists joined the collaboration with specialised drones that could sample the smoke produced.
"It's a really novel way of looking at the chemical components in the smoke, so we're particularly interested in methane and nitrous oxide," Mr Yates said.
Ticking carbon neutral
The new research will be submitted to the federal government for accreditation.
A successful result would mean that groups such as the Ngurrara rangers can sell carbon credits to businesses that offset emissions, including airlines, and further fund their fire management.
The combination of science and Indigenous land management makes for particularly satisfying work for Mr Yates.
"It's not just an opportunity to reduce your carbon emissions, but it's also offering employment and opportunities for regional and remote communities across northern Australia," he said.
"Which actually makes doing your job quite enjoyable."
As an Indigenous ranger working on his traditional country, the work has also been deeply satisfying for Justin Andrews.
"When you're working out there you feel the presence of the spirit of the people who were living there in the past," Mr Andrews said.
"And it will probably give us the opportunity of more funding and more windows opening for opportunities and work for younger people in our communities."
