Jul 12, 2022 08:04 PM
https://www.newsweek.com/methane-levels-...ts-1723426
EXCERPTS: Methane concentrations in the Earth's atmosphere are soaring—and the exact causes of the "frightening" increase are puzzling scientists.
In April 2022, the National Oceanic and Atmospheric Administration (NOAA) reported that concentrations of the gas averaged 1,895.7 parts per billion (ppb) over the past year, a new record. In fact, the NOAA report showed that 2021 saw a rise of 17 ppb: the largest annual increase in atmospheric methane levels since systematic measurements began in 1983.
"Methane concentrations are increasing at a frightening and totally unexpected rate," NASA atmospheric scientist Benjamin Poulter told Newsweek. "In 2020 and again in 2021, methane concentrations grew at a rate that was more than double the average over the previous decade."
Scientists say the rapid rise in atmospheric methane has significant implications because it is a potent greenhouse gas and can contribute to global warming.
[...] "We don't fully know what is driving the recent increases and there are likely multiple causes," Nisbet said. "But since 2007 the carbon-12 percentage content of methane in the air has been increasing. That suggests much of the new growth is from biological sources such as cattle, natural wetlands and landfills."
Moreover, measurements from a collaborative global network run by the NOAA indicate that much of the growth has been in the tropics and sub-tropics, suggesting that biological emissions from wetlands and/or farming in these regions are rising.
"Much of the growth is in the tropics but we don't now if it is cattle or wetlands or very likely both," he said.
"There have been some recent studies on wetlands in Africa and Bolivia with huge emissions. And the cattle populations of India and Africa are huge, with extremely rapid human population growth, which gets a very large amount of its food from ruminants on pastureland. Landfill emissions are also biological and likely growing very fast in the tropics though declining in Europe and the United States."
[...] However, Nisbet said it is also a possibility that the capacity of the atmosphere to degrade and destroy methane through certain chemical reactions is also declining. "Maybe all factors are acting," he said.
[...] As methane levels rise, scientists are now questioning whether or not a climate change-related feedback loop has been triggered where global warming leads to higher methane emissions, which feeds further warming. Some already believe there is a chance that this process is underway, although the answer is not yet clear.
"Is warming feeding the warming? It's an incredibly important question," Nisbet told Nature magazine. "As yet, no answer, but it very much looks that way."
[...] "An increase in human agriculture will likely occur with more ruminants, more crops, more crop waste fires, more use of fertilizer running off into wetlands, all leading to methane emission," Nisbet wrote in an article published in the journal Philosophical Transactions A... (MORE - missing details)
EXCERPTS: Methane concentrations in the Earth's atmosphere are soaring—and the exact causes of the "frightening" increase are puzzling scientists.
In April 2022, the National Oceanic and Atmospheric Administration (NOAA) reported that concentrations of the gas averaged 1,895.7 parts per billion (ppb) over the past year, a new record. In fact, the NOAA report showed that 2021 saw a rise of 17 ppb: the largest annual increase in atmospheric methane levels since systematic measurements began in 1983.
"Methane concentrations are increasing at a frightening and totally unexpected rate," NASA atmospheric scientist Benjamin Poulter told Newsweek. "In 2020 and again in 2021, methane concentrations grew at a rate that was more than double the average over the previous decade."
Scientists say the rapid rise in atmospheric methane has significant implications because it is a potent greenhouse gas and can contribute to global warming.
[...] "We don't fully know what is driving the recent increases and there are likely multiple causes," Nisbet said. "But since 2007 the carbon-12 percentage content of methane in the air has been increasing. That suggests much of the new growth is from biological sources such as cattle, natural wetlands and landfills."
Moreover, measurements from a collaborative global network run by the NOAA indicate that much of the growth has been in the tropics and sub-tropics, suggesting that biological emissions from wetlands and/or farming in these regions are rising.
"Much of the growth is in the tropics but we don't now if it is cattle or wetlands or very likely both," he said.
"There have been some recent studies on wetlands in Africa and Bolivia with huge emissions. And the cattle populations of India and Africa are huge, with extremely rapid human population growth, which gets a very large amount of its food from ruminants on pastureland. Landfill emissions are also biological and likely growing very fast in the tropics though declining in Europe and the United States."
[...] However, Nisbet said it is also a possibility that the capacity of the atmosphere to degrade and destroy methane through certain chemical reactions is also declining. "Maybe all factors are acting," he said.
[...] As methane levels rise, scientists are now questioning whether or not a climate change-related feedback loop has been triggered where global warming leads to higher methane emissions, which feeds further warming. Some already believe there is a chance that this process is underway, although the answer is not yet clear.
"Is warming feeding the warming? It's an incredibly important question," Nisbet told Nature magazine. "As yet, no answer, but it very much looks that way."
[...] "An increase in human agriculture will likely occur with more ruminants, more crops, more crop waste fires, more use of fertilizer running off into wetlands, all leading to methane emission," Nisbet wrote in an article published in the journal Philosophical Transactions A... (MORE - missing details)
