CLIMATE WIRE | Boreal forest fires across northern Eurasia and North America – including parts of Canada, Alaska and Siberia – spewed record levels of carbon dioxide into the atmosphere in 2021, according to new research.
In a typical year, these northern fires account for about 10% of the planet’s wildfire-related carbon emissions. But in 2021, their share has skyrocketed to 23%.
The heat and dryness are likely to blame, the researchers say. North America and Eurasia both experienced strong heat waves in the summer of 2021, and Eurasia also suffered from low rainfall and drought.
And while 2021 broke records for wildfire emissions, boreal fires have worsened for decades alongside climate change. Research finds emissions from these fires in the North have been steadily increasing since at least 2000.
“Boreal forests could be a carbon ticking time bomb, and the recent increases in wildfire emissions we’re seeing make me fear the clock is ticking,” said study co-author Steven Davis, a scientist from the earth system at the University of California, Irvine, in a statement.
The new study, published Thursday in the journal Scienceused satellite data to track wildfire emissions between 2000 and 2021.
Tracking fire-related carbon dioxide is important for climatologists. These global warming emissions can accelerate the rate of global warming, further worsening the hot, dry conditions that cause wildfires.
But it can be difficult to directly measure fire-related carbon dioxide emissions using satellites, the researchers note. CO2 remains in the atmosphere for a long time, which makes it difficult to identify its source.
But carbon monoxide, another type of wildfire emission, is a different story. Carbon monoxide has a much shorter lifespan in the atmosphere and is much easier to attribute directly to wildfires. Scientists can observe the amount of carbon monoxide released by a fire and then use these measurements to estimate how much carbon dioxide was released alongside it.
The researchers, led by Bo Zheng of Tsinghua University in China, used this special method to estimate carbon dioxide emissions from boreal forest fires. In 2021, they found, boreal fires dumped nearly half a billion tons of carbon into the atmosphere.
Boreal fires, in general, are of increasing concern to climatologists. They often occur in carbon-rich peat landscapes and tend to produce more carbon dioxide than other ecosystems when they burn.
This means they have a higher potential to influence the global climate and get trapped in vicious feedback cycles – more fires release more carbon, leading to more warming, leading to more fires.
“These fires represent two decades of rapid warming and extreme drought across northern Canada and Siberia, and unfortunately even this new record high may not last long,” Davis said in a statement.
Reprinted from E&E News courtesy of POLITICO, LLC. Copyright 2023. E&E News provides essential information for energy and environmental professionals.