It is the most effective lever in the short term to slow the pace of climate change. And yet, States do not seem determined to implement it. Emissions and concentrations of methane (CH4) in the atmosphere continues to increase, at a rate that has accelerated significantly in recent years, despite promises by many countries to drastically reduce them. These results come from the new global assessment of methane, published on Tuesday, September 10 in the journal Environmental Research Letters by sixty-nine scientists from the Global Carbon Project consortium, four years after the previous edition.
They are all the more serious since methane, the second most important greenhouse gas after carbon dioxide (CO2), is responsible for about a third of global warming since the pre-industrial era. If the CH4 lasts less time in the atmosphere (about nine years compared to several centuries) for carbon dioxide), its warming power is much greater than that of CO2 : more than 80 times greater in twenty years and 30 times over a hundred-year horizon.
The concentration of methane in the atmosphere, which has been increasing since 2007, has reached a record growth rate in the last five years since records began in the 1980s.
Result: the concentration of CH4 The atmospheric level in January stood at 1,931 parts per billion, a level not seen in at least eight hundred thousand years. “Methane is growing faster in relative terms than any other major greenhouse gas and is now 2.6 times higher than in pre-industrial times”specify the authors of the study.
A catastrophic scenario for humans and ecosystems
This trend “We cannot continue if we want to maintain a habitable climate”they write again. In fact, the current trajectory is leading the planet towards warming. “more than 3°C by the end of the century”, compared to the pre-industrial era. Such a rise in mercury, far removed from the Paris Agreement’s goals of staying well below a 2°C rise and, if possible, 1.5°C, would be catastrophic for humans and ecosystems. There are already heat waves, droughts, floods and fires, while the planet has warmed by 1.2°C.
“This increase is mainly due to the rise in emissions linked to human activities, firstly the fossil fuel sector, followed by agriculture and waste”explains Marielle Saunois, professor-researcher at the Laboratory of Climate and Environmental Sciences and coordinator of the study.
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