Why Methane Matters: The Short-Lived Gas with a Big Impact

Since about 2006, methane levels in Earth’s atmosphere have been climbing fast — mostly because of human activities. It is a super-powerful greenhouse gas that traps heat, but it doesn’t last as long in the air as carbon dioxide does. It’s also the second-largest contributor to rising global temperatures after carbon dioxide (CO₂). It’s already added about half a degree Celsius of global warming since the late 1800s.

To keep global warming within the limits of the Paris Agreement, we have to cut methane emissions quickly and deeply. Natural sources like wetlands are hard to control, so the biggest opportunity is reducing this human-made (anthropogenic) greenhouse gas — from things like fossil fuels, farming, and waste.

What’s Behind the Increase?

Since 2006, scientists have seen record-high growth in methane. Evidence shows that much of this comes from biological sources, like livestock, landfills, and tropical wetlands. Another piece of the puzzle may be that methane is not breaking down as fast as before. Normally, it reacts with a chemical in the air called the hydroxyl radical (OH). If there’s less OH around, methane sticks around longer.

Methane from natural systems—like wetlands and thawing Arctic soils (permafrost)—also seems to be rising. During recent La Niña years, for example, wetter tropical areas released more methane. When the weather switched to El Niño, methane growth slowed down. In the Arctic, warming and “greening” (more plants growing) may also be increasing methane releases, especially during heatwaves. Scientists are still improving their tools—like satellites and sensors—to track these changes and figure out exactly where the gas is coming from. NASA’s EMIT instrument on the International Space Station (ISS) detects methane plumes from large emission sources. Scientists also use instruments on airplanes to detect methane in the atmosphere. These aircraft carry instruments similar to NASA’s EMIT sensor, but they zoom in on smaller areas. Because planes fly lower and focus on local regions, they can capture sharper, more detailed measurements and help fill in the gaps between satellite passes.

The Human Contribution

Over the past decade, human activities have made up roughly two-thirds of total methane emissions. The main sources are:

• Fossil fuels (oil, gas, and coal production)
• Agriculture (mostly livestock and rice paddies)
• Waste (landfills and sewage)

Different ways of measuring methane—like on-the-ground reports, satellite data, and isotope analysis—sometimes give slightly different results, but they all point to the same big picture: humans are driving most of the increase.

Cutting Methane Emissions

The good news is we already know how to reduce methane. In the energy and waste sectors, fixing leaks, improving efficiency, and capturing methane can be cheap and effective. This is where NASA satellites and instruments can spot “super-emitters” — facilities releasing huge amounts of methane — so they can be repaired quickly.

In agriculture, it’s tougher but still possible. Changing livestock feed, managing manure better, drying rice fields between floods, eating less meat, and wasting less food all help.

Some scientists are also studying ways to remove methane from the air, but those technologies are still experimental.

Taking Action Globally

Many countries have joined the Global Methane Pledge, promising to cut methane emissions by 30% by 2030. To reach that goal, each country needs clear and enforceable plans that track methane separately from other greenhouse gases.

Laws like the U.S. EPA’s “super-emitter” rule, if it is still active today, and the European Union’s new methane regulations are examples of how governments can make real progress. But right now, only about 13% of global methane emissions are covered by strong policies — far from what’s needed to stay below 1.5 °C of warming.

What’s the Bottom Line?

Methane may vanish faster than CO₂, but it packs a punch.
Cutting methane now buys us time while we tackle the bigger, longer-term challenge of carbon dioxide.

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