Cutting methane emissions is a cost-effective and relatively quick way to limit global temperature rise, according to a new United Nations–backed report.
Only in the past decade have scientists been able to estimate the amount and sources of these emissions, allowing a greater understanding of the difference reducing methane pollution can make for climate change.
How do methane emissions contribute to climate change?
Methane is one of several greenhouse gases, which trap the sun’s heat in the atmosphere and thus cause the global average temperature to rise. Accounting for about 20 percent of global emissions, methane is the second-most-prevalent greenhouse gas after carbon dioxide, which makes up more than 70 percent.
Sometimes called a “super pollutant,” methane is many times more powerful than carbon dioxide at trapping heat. But it breaks down much more quickly: methane is mostly gone from the atmosphere after a decade, while carbon dioxide can contribute to global warming for hundreds of years.
What would cutting methane emissions accomplish?
It could have some fairly immediate benefits. Reducing methane emissions—in tandem with efforts to reduce carbon dioxide emissions—would quickly lower the concentrations of the gas in the atmosphere, helping to mitigate some of the harmful effects of climate change in the coming years.
The UN-supported report’s authors say that cutting methane emissions by nearly half within the next decade would prevent a 0.3°C rise in the average global temperature by the 2040s. Such cuts are necessary to achieve the Paris Agreement’s goal of preventing a temperature rise of 1.5°C above preindustrial levels.
The report also lays out some ways lowering emissions could improve public health. Cutting one million metric tons of methane—roughly the equivalent of Estonia’s annual methane emissions—would prevent an estimated 1,430 premature deaths, 90 hospital visits, and 145,000 tons of crop losses every year. In economic terms, every ton of methane reduced would provide $4,300 in benefits.
Is it doable?
Many technologies to reduce methane emissions are already in use around the world. Unlike strategies to curb carbon dioxide emissions, such as carbon capture and storage, many of those to reduce methane are inexpensive. According to the report, half of the targeted measures that emitters could take would eventually pay for themselves.
“For methane, we have technology in place to do these dramatic reductions,” says Steven Hamburg, chief scientist at Environmental Defense Fund. “We just need to make them the norm instead of the exception.”
What are some changes that industries can make?
Agriculture. The agricultural sector accounts for an estimated 40 percent of human-caused methane emissions. Reduction strategies include preventing the burning of fields after harvests, adjusting feed for livestock so that they release less methane, and regularly draining rice paddies.
Fossil fuels. The industry, which makes up about 35 percent of emissions, has the most potential for reductions, the UN-backed report says. Almost all measures could be implemented at low costs. These include improving the detection and repair of methane leaks at oil and gas facilities and flooding abandoned coal mines that leak the gas.
Waste. The sector accounts for 20 percent of emissions. When organic material in landfills and in wastewater decomposes, it releases methane. Mitigation strategies include reducing waste that ends up in landfills, such as by recycling and composting; capturing methane gas; and burning methane gas, which is known as flaring.
Have countries committed to reducing methane emissions as part of their broader climate goals?
Most countries have not included methane mitigation in their pledges under the Paris accord, which are known as nationally determined contributions (NDCs). But an increasing number are placing regulations on methane as awareness of the issue grows.
Countries around the world have implemented a variety of policies, such as setting industry-specific standards, requiring companies to report their emissions, and taxing emissions. In its most recent five-year plan, China—the world’s top methane emitter—mentioned cutting methane emissions for the first time. Last year, the European Commission adopted a methane strategy [PDF], signaling potential for new emissions policies across the European Union.
Meanwhile, the United States has indicated a renewed interest in tackling the issue. President Donald Trump’s administration rolled back landmark regulations imposed under President Barack Obama, but some in Congress are working to restore them. The Joe Biden administration has said it will work to “reduce non-CO2 greenhouse gases, including methane.” Still, the country’s new NDCs, which aim to halve total emissions from its 2005 level by 2030, don’t specifically name methane.
Companies, including many oil and gas giants, have also made pledges regarding methane, although some analysts are skeptical they will follow through. “We have to make sure it actually happens,” says Hamburg.