The fires sweeping Australia probably have doubled the nation’s annual greenhouse-gas emissions, producing as much climate-damaging pollution as all the airplanes in the world, new research shows.
The bushfires likely contributed 900 million metric tonnes of carbon emissions, according to early estimates from scientists behind the Global Fire Emissions Database. That compares with 532 million tons of emissions from Australia for the year through June and about 918 million tonnes that the International Council on Clean Transportation counted from commercial aircraft worldwide in 2018.
Fires typically burn between September and March in Australia, which coincides with spring and summer months in the southern hemisphere. This year, the worst-ever fire season decimated an area the size of England, killing at least 28 people and destroying 3,000 homes. Experts say the blazes may have led to the death of one and could shave 1.6 per cent off gross domestic product in Australia this year.
“One of the factors that makes this an unprecedented fire season is the affected area across the southeast, which is made up of temperate forests that grow back much more slowly.”– Guido van der Werf, a scientist at Vrije Universiteit Amsterdam
A large amount of uncertainty accompanies efforts to measure emissions caused by wildfires. The actual figure could fall between 650 million metric tonnes and 1.2 billion metric tonnes of carbon dioxide. Even on the lower bound, the 2019 fire emissions are likely to be the largest in records that stretch back to 1997, when satellites began monitoring the pollution caused by brushfires.
Australia is not alone in seeing its climate impact change dramatically by a disaster. In 2017, Chile suffered its worst wildfire season ever and produced emissions from the burning equivalent to 90 per cent of the country’s annual greenhouse-gas output, according to Universidad de Chile’s Center for Climate and Resilience.
Fires have long been a part of Australian landscapes, where savannahs, grasslands and open woodlands burn each year. Typically, it takes only a few years for the carbon released in such fires to be reabsorbed as grass and plants regrow, according to Rebecca Buchholz, a scientist at the U.S. National Center for Atmospheric Research. “But that may be being pushed out of balance.”
One of the factors that makes this an unprecedented fire season is the affected area across the southeast, which is made up of temperate forests that grow back much more slowly. About half the carbon emissions in this fire season have come from this region, said Guido van der Werf, a scientist at Vrije Universiteit Amsterdam. “Those emissions may be reabsorbed or may be not,” he said. “It depends on when the next fire arrives.”
While Australia’s greenhouse-gas pollution makes up just one per cent of the world’s total, the country ranks second when it comes to per-capita emissions. Australia emitted 16.2 metric tonnes of carbon dioxide per person in 2016, just below Saudi Arabia (16.3 metric tonnes) and slightly more than the United States (15 metric tonnes).