Human Activities are Fueling a Troubling Rise in Methane Emissions

Methane emissions have risen faster over the past five years than in any other time in the historical record, new research finds. This research also posits that human activity is to blame for the release of at least two-thirds of this greenhouse gas.

Methane lasts in the atmosphere for around 12 years, on average, which is short compared to the hundreds to thousands of years lifespan of carbon dioxide. But methane is also more effective at trapping heat: Over a 100-year timeframe, methane is 28 times more potent than carbon, according to the Environmental Protection Agency, and over a 20-year timeframe, methane is 84 times more potent.

Despite increasing attention on methane emissions, a new estimate finds that annual methane emissions have increased by 15–20%, or 50–60 million tons, since 2000. Global anthropogenic methane emissions totalled approximately 384 million tons per year from 2018 to 2020.

“Human activities now release at least two-thirds of global methane emissions,” says study leader Rob Jackson, an environmental scientist at Stanford Univ. “That percentage has gone up in the last few decades. Concentrations are also rising, and they have risen faster in the last five years than any time over the instrument record.”

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▲ A new study estimated that methane emissions have increased 15–20% since 2000. Human activities, including oil and gas extraction and animal husbandry, are largely to blame.

Methane comes from both natural and anthropogenic sources. The largest natural sources are wetlands and freshwater lakes, rivers, and ponds where methane-emitting bacteria thrive. Human activities that release methane...