Methane emissions from tropical wetlands are on the rise, jeopardizing climate initiatives
Methane emissions from tropical wetlands are on the rise, posing a significant risk to climate strategies.
TroibNews 
The warming tropical wetlands are releasing increasing amounts of methane, signaling a concerning trend that the world's climate targets may be increasingly unattainable. Recent research indicates that this significant rise in methane emissions from wetlands—largely unreported by national emissions frameworks and underestimated in scientific models—might compel governments to enforce more stringent reductions in their fossil fuel and agricultural sectors.
Wetlands sequester vast quantities of carbon in dead plant material, which is gradually decomposed by soil microbes. However, with rising temperatures, this decomposition process accelerates, enhancing the biological interactions that generate methane. Additionally, intense rainfall associated with climate change leads to flooding, which contributes to the expansion of wetlands.
While scientists had anticipated that wetland methane output would increase with climate change, atmospheric samples collected between 2020 and 2022 indicated the highest methane levels recorded since reliable measurements began in the 1980s. Four recent studies suggest that tropical wetlands are a significant source of this increase, contributing over 7 million tonnes of methane in recent years.
"Methane concentrations are not just rising, but rising faster in the last five years than any time in the instrument record," remarked Rob Jackson, an environmental scientist from Stanford University and chair of the group responsible for publishing the five-year Global Methane Budget, with the latest release in September.
Satellite data has identified the tropics as the origin of a notable rise in methane. By examining specific chemical signatures in the methane, researchers determined its natural source as wetlands rather than fossil fuels. The Congo, Southeast Asia, and the Amazon and southern Brazil were found to be key contributors to the tropical methane spike.
A study published in March 2023 in Nature Climate Change revealed that annual emissions from wetlands over the past twenty years were approximately 500,000 tonnes per year higher than predictions made under worst-case climate scenarios. Addressing emissions from wetlands remains a significant technological challenge.
"We should probably be a bit more worried than we are," stated Drew Shindell, a climate scientist at Duke University.
The La Nina climate pattern, which typically brings heavier rainfall to certain tropical regions, has been implicated in the recent surge according to a study in September published in the Proceedings of the National Academy of Sciences. However, Shindell noted that La Nina alone, which concluded in 2023, does not fully account for the record-high emissions.
For nations striving to address climate change, "this has major implications when planning for methane and carbon dioxide emissions cuts," commented Zhen Qu, an atmospheric chemist at North Carolina State University and lead author of the La Nina study.
If wetland methane emissions continue to rise, experts assert that governments will be pressured to implement more aggressive measures to limit warming to 1.5 degrees Celsius, consistent with commitments made in the United Nations Paris climate agreement.
Methane is known to be 80 times more potent than carbon dioxide for heat retention over a 20-year period, and it contributes to about one-third of the observed 1.3 degrees Celsius warming since 1850. Unlike carbon dioxide, however, methane dissipates from the atmosphere after approximately a decade, resulting in less long-lasting effects.
Over 150 countries have committed to achieving a 30 percent reduction from 2020 levels by 2030, focusing on issues such as leaking oil and gas infrastructure. However, scientists have yet to observe any reduction in emissions, despite advancements in technologies for detection. Methane output from fossil fuel sources has remained around the record high of 120 million tonnes since 2019, according to the International Energy Agency's 2024 Global Methane Tracker report.
Satellites have detected over 1,000 significant methane plumes from oil and gas operations in the last two years, as noted in a recent UN Environment Programme report, but only 12 leaks received attention from the identified countries.
Several nations have proposed robust methane-cutting strategies. Last year, China announced plans to mitigate flaring— the practice of burning off emissions at oil and gas facilities. Meanwhile, President Joe Biden's administration recently finalized a methane fee targeting major oil and gas companies, although it is anticipated that this initiative may be abandoned with the potential return of Donald Trump to the presidency.
Eve Bazaiba, the Democratic Republic of Congo's Environment Minister, shared with Reuters during the UN climate summit, COP29, that the nation is evaluating the surge of methane emissions from the swampy forests and wetlands of the Congo Basin, which was identified as a significant methane hotspot in the 2024 budget report.
"We don't know how much [methane is coming off our wetlands]," she stated. "That's why we bring in those who can invest in this way, also to do the monitoring to do the inventory, how much we have, how we can also exploit them."
Rohan Mehta contributed to this report for TROIB News
Wetlands sequester vast quantities of carbon in dead plant material, which is gradually decomposed by soil microbes. However, with rising temperatures, this decomposition process accelerates, enhancing the biological interactions that generate methane. Additionally, intense rainfall associated with climate change leads to flooding, which contributes to the expansion of wetlands.
While scientists had anticipated that wetland methane output would increase with climate change, atmospheric samples collected between 2020 and 2022 indicated the highest methane levels recorded since reliable measurements began in the 1980s. Four recent studies suggest that tropical wetlands are a significant source of this increase, contributing over 7 million tonnes of methane in recent years.
"Methane concentrations are not just rising, but rising faster in the last five years than any time in the instrument record," remarked Rob Jackson, an environmental scientist from Stanford University and chair of the group responsible for publishing the five-year Global Methane Budget, with the latest release in September.
Satellite data has identified the tropics as the origin of a notable rise in methane. By examining specific chemical signatures in the methane, researchers determined its natural source as wetlands rather than fossil fuels. The Congo, Southeast Asia, and the Amazon and southern Brazil were found to be key contributors to the tropical methane spike.
A study published in March 2023 in Nature Climate Change revealed that annual emissions from wetlands over the past twenty years were approximately 500,000 tonnes per year higher than predictions made under worst-case climate scenarios. Addressing emissions from wetlands remains a significant technological challenge.
"We should probably be a bit more worried than we are," stated Drew Shindell, a climate scientist at Duke University.
The La Nina climate pattern, which typically brings heavier rainfall to certain tropical regions, has been implicated in the recent surge according to a study in September published in the Proceedings of the National Academy of Sciences. However, Shindell noted that La Nina alone, which concluded in 2023, does not fully account for the record-high emissions.
For nations striving to address climate change, "this has major implications when planning for methane and carbon dioxide emissions cuts," commented Zhen Qu, an atmospheric chemist at North Carolina State University and lead author of the La Nina study.
If wetland methane emissions continue to rise, experts assert that governments will be pressured to implement more aggressive measures to limit warming to 1.5 degrees Celsius, consistent with commitments made in the United Nations Paris climate agreement.
Methane is known to be 80 times more potent than carbon dioxide for heat retention over a 20-year period, and it contributes to about one-third of the observed 1.3 degrees Celsius warming since 1850. Unlike carbon dioxide, however, methane dissipates from the atmosphere after approximately a decade, resulting in less long-lasting effects.
Over 150 countries have committed to achieving a 30 percent reduction from 2020 levels by 2030, focusing on issues such as leaking oil and gas infrastructure. However, scientists have yet to observe any reduction in emissions, despite advancements in technologies for detection. Methane output from fossil fuel sources has remained around the record high of 120 million tonnes since 2019, according to the International Energy Agency's 2024 Global Methane Tracker report.
Satellites have detected over 1,000 significant methane plumes from oil and gas operations in the last two years, as noted in a recent UN Environment Programme report, but only 12 leaks received attention from the identified countries.
Several nations have proposed robust methane-cutting strategies. Last year, China announced plans to mitigate flaring— the practice of burning off emissions at oil and gas facilities. Meanwhile, President Joe Biden's administration recently finalized a methane fee targeting major oil and gas companies, although it is anticipated that this initiative may be abandoned with the potential return of Donald Trump to the presidency.
Eve Bazaiba, the Democratic Republic of Congo's Environment Minister, shared with Reuters during the UN climate summit, COP29, that the nation is evaluating the surge of methane emissions from the swampy forests and wetlands of the Congo Basin, which was identified as a significant methane hotspot in the 2024 budget report.
"We don't know how much [methane is coming off our wetlands]," she stated. "That's why we bring in those who can invest in this way, also to do the monitoring to do the inventory, how much we have, how we can also exploit them."
Rohan Mehta contributed to this report for TROIB News
