Methane surge observed
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CSIRO says global methane emissions have surged by 20 per cent over the last two decades.
According to the new Global Methane Budget 2024, this increase in methane, a potent greenhouse gas, is primarily attributed to human activities, with emissions accelerating faster than previously recorded.
Methane, along with carbon dioxide and nitrous oxide, is one of the primary contributors to climate change.
However, methane’s impact is more severe in the short term due to its ability to trap more heat in the atmosphere.
Despite its relatively short lifespan of a few decades compared to carbon dioxide, methane’s potency makes it a crucial target for climate mitigation efforts.
The Global Methane Budget, compiled by international researchers including Australia’s CSIRO, shows that global methane emissions have increased by 61 million metric tonnes annually.
The report says methane concentrations have climbed 2.6 times higher than pre-industrial levels.
Dr Pep Canadell, Executive Director for the Global Carbon Project at CSIRO, says this growth has been particularly pronounced in the last three years.
“We have seen higher growth rates for methane over the past three years, from 2020-2022, with a record high in 2021,” Dr Canadell said.
“Human activities are responsible for at least two-thirds of global methane emissions, adding about 0.5°C to global warming that has occurred to date.”
The report identifies agriculture as the largest source of methane from human activities, responsible for 40 per cent of global emissions.
Fossil fuels contribute 34 per cent, followed by solid waste and wastewater at 19 per cent, and biomass burning at 7 per cent.
In 2020, the top emitters of methane were China (16 per cent), India (9 per cent), the United States (7 per cent), Brazil (6 per cent), and Russia (5 per cent).
Despite global increases, the report says regions such as the European Union and Australasia have successfully reduced methane emissions over the last 20 years.
However, continued global rises could jeopardise the Global Methane Pledge, which aims to cut methane emissions by 30 per cent by 2030.
“Methane is a short-lived greenhouse gas compared to carbon dioxide. Most emissions, and therefore their warming effect, occur during the first 20 years after being released, so it’s a good target for fast mitigation of global warming,” Dr Canadell says.
The report stresses the need for a 45 per cent reduction in methane emissions by 2050 to meet the targets of the Paris Agreement.
Agricultural methane, in particular, presents a significant challenge, but research is underway to develop solutions.
CSIRO is working with partners to explore strategies such as improved animal feed additives, including FutureFeed, which uses seaweed to reduce methane emissions in livestock.
The Global Methane Budget 2024 is the fourth budget published by the Global Carbon Project, with research supported by the Australian Government’s National Environmental Science Program’s Climate Systems Hub.