HQ Team
September 12, 2024: A global goal to reduce methane emissions “seems as distant as a desert oasis” now, as about two-thirds of it comes from human activities such as fossil fuels, agriculture and landfills, researchers find.
More than 150 nations, under a global pledge, have agreed to slash methane emissions by 30% this decade, but a new study shows global methane emissions over the past five years have risen faster than ever.
The world has not hit the brakes on methane emissions, a powerful driver of climate change. The trend “cannot continue if we are to maintain a habitable climate,” the researchers wrote in Environmental Research Letters.
“Right now, the goals of the Global Methane Pledge seem as distant as a desert oasis,” said Rob Jackson, who is the Michelle and Kevin Douglas Provostial Professor at the Stanford Doerr School of Sustainability and the study’s lead author.
“We all hope they aren’t a mirage.”
Highest in 800,000 years
Atmospheric concentrations of methane are now more than 2.6 times higher than in pre-industrial times —the highest they have been in at least 800,000 years.
Methane is a short-lived but highly potent greenhouse gas that comes from natural sources like wetlands and human or “anthropogenic” or human activity sources.
In 2020, the most recent year for which complete data are available, nearly 400 million tons or 65% of global methane emissions came directly from human activities.
Agriculture and waste contribute about two tons of methane for every ton from the fossil fuel industry. According to the researchers, human-caused emissions continued to increase through at least 2023.
Methane release
Reservoirs built by people lead to an estimated 30 million tons of methane emitted every year because newly submerged organic matter releases methane as it decomposes, the researchers said.
“Emissions from reservoirs behind dams are as much a direct human source as methane emissions from a cow or an oil and gas field,” said Jackson.
During the first 20 years after release, methane heats the atmosphere nearly 90 times faster than carbon dioxide, making it a key target for limiting global warming in the near term, according to Stanford University.
The current path leads to global warming above 3 degrees Celsius (5 degrees Fahrenheit) by the end of this century.
Cattle, sheep ranching
Total annual methane emissions have increased by 61 million tons or 20% over the past two decades.
Increases are being driven primarily by the growth of emissions from coal mining, oil and gas production and use, cattle and sheep ranching, and decomposing food and organic waste in landfills.
The world’s five biggest methane emitters are China (16%), India (9%), the United States (7%), Brazil (6%) and Russia (5%).
“Only the European Union and possibly Australia appear to have decreased methane emissions from human activities over the past two decades,” said Marielle Saunois of the Université Paris-Saclay in France, lead author of the Earth System Science Data paper.
“The largest regional increases have come from China and Southeast Asia,” she said.
The atmosphere accumulated nearly 42 million tons of methane in 2020 – twice the amount added on average each year during the 2010s and more than six times the increase seen during the first decade of the 2000s.
