Global methane emissions reach record high

While carbon emissions temporarily dropped during the pandemic, global methane emissions have soared to a record high. The increase is equivalent to putting 350 million more cars on the world’s roads.

Global emissions of methane have reached the highest levels on record, according to research from Stanford University. Increases are being driven primarily by growth of emissions from coal mining, oil and natural gas production, cattle and sheep ranching, and landfills.

Between 2000 and 2017, the greenhouse gas climbed to levels that climate models suggest will lead to 3-4 degrees Celsius of warming before the end of this century, writes a statement.

In 2017, the last year for which complete global methane data are available, Earth’s atmosphere absorbed nearly 600 million tons of the colorless, odorless gas that is 28 times more powerful than carbon dioxide at trapping heat over a 100-year span.

More than half of all methane emissions now come from human activities. Annual methane emissions are up 9 percent, or 50 million tons per year, from the early 2000s, when methane concentrations in the atmosphere were relatively stable.

In terms of warming potential, adding this much extra methane to the atmosphere since 2000 is akin to putting 350 million more cars on the world’s roads or doubling the total emissions of Germany or France. Globally, fossil fuel sources and cows are twin engines powering methane’s upward climb, writes the statement.

“Emissions from cattle and other ruminants are almost as large as those from the fossil fuel industry for methane,” said Stanford University scientist Rob Jackson. “People joke about burping cows without realizing how big the source really is.”

Throughout the study period, agriculture accounted for roughly two-thirds of all methane emissions related to human activities; fossil fuels contributed most of the remaining third.

Methane emissions from agriculture rose to 227 million tons of methane in 2017, up nearly 11 percent from the 2000–2006 average. Methane from fossil fuel production and use reached 108 million tons in 2017, up nearly 15 percent from the earlier period.

Amid the coronavirus pandemic, carbon emissions plummeted as manufacturing and transportation ground to a halt, says the statement. “There’s no chance that methane emissions dropped as much as carbon dioxide emissions because of the virus,” Jackson said. “We’re still heating our homes and buildings, and agriculture keeps growing.”

“Natural gas use is rising quickly here in the U.S. and globally,” Jackson continued. “It’s offsetting coal in the electricity sector and reducing carbon dioxide emissions, but increasing methane emissions in that sector.”

According to Jackson and colleagues, curbing methane emissions will require reducing fossil fuel use and controlling fugitive emissions such as leaks from pipelines and wells, as well as changes to the way we feed cattle, grow rice and eat.

Image credit: Genta, flickr/Creative Commons

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