Do wild fires only destroy homes, plant life and animals? On the other hand, do they have more risk? A group of researchers in the journal One Earth warned that brown carbon released by burning biomass in the northern hemisphere is accelerating warming in the Arctic. They also warned that this could lead to even more wildfires in the future.
In their work supported by the National Natural Science Foundation of China, the researchers point out that wildfires have much more risk than mere destroying the wildlife and biodiversity. Blazing wildfires are accompanied by vast plumes of brown smoke, made up of particles of brown carbon suspended in the air. This smoke poses health hazards, and can even block out the summer sun, and researchers suspected that it might also be contributing to global warming, the researchers said.
It was in 2017 that the Chinese icebreaker vessel Xue Long headed for the Arctic Ocean to examine which aerosols were floating around Arctic air and to identify their sources. The scientists were particularly curious about how brown carbon released by wildfires was affecting the climate and how its warming effects compared to those of denser black carbon from high-temperature fossil fuel burning, the second most powerful warming agent after carbon dioxide. They found that brown carbon was contributing to warming more than previously thought.
“To our surprise, observational analyses and numerical simulations show that the warming effect of brown carbon aerosols over the Arctic is up to about 30% of that of black carbon,” said senior author Pingging Fu, an atmospheric chemist at Tianjin University. They said that the Arctic has been warming at a rate three times that of the rest of the planet in the last 50 years. They claimed that wildfires augmented this. The researchers found that brown carbon from burning biomass was responsible for at least twice as much warming as brown carbon from fossil fuel burning.
Like black carbon and carbon dioxide, brown carbon warms the planet by absorbing solar radiation. Since warming temperatures have been linked to the rise in wildfires in recent years, this leads to a positive feedback loop. “The increase in brown carbon aerosols will lead to global or regional warming, which increases the probability and frequency of wildfires,” says Fu. “Increased wildfire events will emit more brown carbon aerosols, further heating the earth, thus making wildfires more frequent.” The risk of fire is growing, and a report published by the UN last month warned that wildfires are on track to increase 50% by 2050.
One Earth (@OneEarth_CP), published by Cell Press, is a monthly journal that features papers from the fields of natural, social, and applied sciences.