According to an international team of researchers led by Earth system scientists at the University of California, Irvine, carbon dioxide emissions from wildfires, which have been steadily increasing since 2000, reached a new high in 2021.
According to a paper published in Science, nearly half a gigatonne of carbon (or 1.76 billion tons of CO2) was released from burning boreal forests in North America and Eurasia in 2021, 150% higher than annual mean CO2 emissions between 2000 and 2020.
Wildfires in 2021 emitted a record-breaking amount of carbon dioxide
GUILLERMO SALGADO/AFP via Getty Images
According to our measurements, boreal fires in 2021 will break all previous records, said senior co-author Steven Davis, an Earth system science professor at UCI, as per ScienceDaily.
These fires are the result of two decades of rapid warming and extreme drought in Northern Canada and Siberia, and unfortunately, even this new record may not last long.
According to the researchers, the worsening fires are part of a climate-fire feedback loop in which carbon dioxide emissions warm the planet, creating conditions conducive to more fires and emissions.
According to co-author Yang Chen, a UCI research scientist in Earth system science, the escalation of wildfires in the boreal region is expected to accelerate the release of the large carbon storage in the permafrost soil layer as well as contribute to the northward expansion of shrubs.
These factors may contribute to further warming and create a more favorable environment for the occurrence of wildfires.
According to Davis, Boreal fires will emit nearly twice as much CO2 as global aviation in 2021.
If this level of emissions from unmanaged lands becomes the new normal, stabilizing the Earth's climate will be even more difficult than previously thought.
For a variety of reasons, Earth system scientists find it difficult to analyze the amount of carbon dioxide released during wildfires.
During a combustion event, satellite observations are hampered by rugged, smoke-engulfed terrain, and space-based measurements are not at a fine enough resolution to reveal details of CO2 emissions.
According to the researchers, models used to simulate fuel load, fuel consumption, and fire efficiency work well under normal conditions but are not robust enough to represent extreme wildfires.
The team overcame these obstacles by studying carbon monoxide released into the atmosphere during fires.
The team reconstructed changes in global fire CO2 emissions from 2000 to 2021 by combining CO readings from the MOPITT satellite instrument with existing fire emissions and wind speed datasets.
Because carbon monoxide has a shorter lifetime in the atmosphere than CO2, scientists can detect an abnormal abundance of CO as evidence of fires.
Cecile Juliette, public information officer for the California Department of Forestry and Fire Protection, stated in January 2022.
"We are nearing the end of January. We used to refer to it as the California fire season because fires would start in July and last until September or October," Juliette said as per Disaster Philanthropy.
"So it had only been a few months. Our fires are now extending all the way through December and into January, so calling it a fire season is no longer accurate."
While the number of wildfires and acres burned were higher than the 10-year average, experts say the season could have been much worse.
Unexpected rains aided in the suppression of severe fire seasons in New Mexico and Alaska.
In California, resource availability was important, but so were weather conditions that were consistently favorable to the state.
Climate change, on the other hand, is making fire seasons worse in general.
Extreme drought and rising temperatures continue to dry out forests and are the primary causes of an increase in fire weather. According to the United States.
According to Drought Monitor, extreme conditions are more widespread than they have been in at least 20 years, increasing the risk of large, severe fires.
