After the alarmism and hysteria about CO2 is losing effectiveness, the next scarecrow is being rolled out! At least according to the AAAS!
Expect more atmospheric methane related news to come out in the coming months.
Such alarmism and hysteria is good business for science! More grants, funding, employment etc.
Greenhouse gas is another one of those terms of demagoguery! Earth's atmosphere is not a greenhouse! Those analogies are just absurd and misleading!
Methane is even more an atmospheric trace gas than CO2! "CO2 is currently around 420 parts per million and methane is around 1934 parts per billion." (Google search) It is roughly 200 times less than CO2, if my math is correct. Supposedly, methane is estimated to be about 80 times more potent as a greenhouse gas than CO2.
Oddly enough, the cited study is only about one year, i.e. 2020! The study itself does not seem to draw a connection to greenhouse gasses.
"Atmospheric Methane/A growing influence ...
The atmospheric concentration of methane, the second most important greenhouse gas after carbon dioxide, increased markedly during the year 2020. Potential causes for this increase include greater wetland methane emissions or lower atmospheric OH abundance due to lower nitrogen oxide emissions during the COVID-related slowdown. Now, Yoon et al. suggest another possible reason: anomalously high atmospheric isoprene abundances. Isoprene oxidation reduces the amount of OH in the atmosphere, in turn leading to lower rates of methane destruction and thus higher methane concentrations, illustrating another way that the biosphere could have affected the methane budget that year."
From the abstract:
"Recent observations show anomalously high methane growth in 2020, which has been attributed to increased wetland emissions and decreased OH from lower COVID-19 nitrogen oxide (NOx) emissions. NOx is not the only species that affects OH—isoprene, the most significant non-methane hydrocarbon by total emissions, is oxidized by OH, which can deplete OH during periods of high emissions. Using satellite isoprene retrievals from the Cross-track infrared sounder (CrIS), we find anomalously high isoprene columns during 2020, coincident with high methane growth. Isoprene's oxidation produces carbon monoxide, which can be transported over longer distances and decrease OH outside of isoprene source regions. Elevated isoprene concentrations may have contributed 13% (bounds: 10%–28%) of 2020's methane growth if we assume no change in NOx emissions in 2020. Since COVID-19 decreased anthropogenic NOx emissions, this estimate is an upper-limit and may depend on whether isoprene or NO emissions drove this isoprene anomaly."
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