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Excessive methane emitted from mega wildfires fuels vicious cycle: Study

Researchers have found that the amount of methane gas emitted from mega wildfires was grossly underestimated

Source: FRANCE 24 English twitter handle

Source: FRANCE 24 English twitter handle

BS Web Team New Delhi

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A new detection method for methane emissions from mega wildfires has found that the amount of the gas released from these fires is much more than estimated using earlier methods. 

The paper titled 'Ground solar absorption observations of total column CO, CO2, CH4, and aerosol optical depth from California's Sequoia Lightning Complex Fire: emission factors and modified combustion efficiency at regional scales' published in the peer-reviewed journal Atmospheric Chemistry and Physics studied the recent mega wildfires in California using new remote methane detection technique and found that massive amounts of the gas are being released from those. 

The researchers discovered over 20 gigagrams of methane emitted by the 2020 Sequoia Lightning Fire Complex in the Sierra Nevadas, a mountain range in eastern California, using this remote technique. A gigagram is equivalent to 1,000 metric tonnes.

According to the researchers, this data matched readings from European space agency satellite data, which had a broader, worldwide view of the burned areas but was unable to quantify methane under these conditions.

Traditionally, scientists evaluated such emissions by examining wildlife air samples acquired via aeroplane, a procedure that, according to the researchers, is costly and difficult to implement.

"For 2020, wildfires would have been the third biggest source of methane in the state. Fires are getting bigger and more intense. Typically, these sources have been hard to measure, and it's questionable whether they're under our control. But we have to try. They're offsetting what we're trying to reduce," environmental sciences professor at University of California, Riverside (UCR) and study co-author Francesca Hopkins in a statement.

According to scientists, climate change has been fueling the severity, range and frequency of wildfires which emit methane that in turn accelerates the said climate change, researchers highlighted adding that it is 25 times as potent at trapping heat as carbon dioxide, in the short term.  

The study also discovered that, even though methane-emitting wildfires were not new, the amount of methane emitted by the top 20 fires in 2020 was more than seven times the average from wildfires in the previous 19 years.

Scientists said, "Methane warms the planet 86 times more intensely than carbon dioxide over 20 years. The state would struggle to meet its needed cleaner air and climate targets without accounting for this source."

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First Published: Apr 21 2023 | 7:37 PM IST

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