Explainer: How Methane Leaks Accelerate Global Warming

September 27 (Reuters) – Methane leaks have become a major threat to the global climate, with the latest incident involving two Russian gas pipelines under the Baltic Sea that have been at the heart of an energy crisis since Russia invaded Ukraine .

Methane, the main component of natural gas, can leak from pipelines and drilling sites, and is also emitted from agricultural and food waste.

Research increasingly shows that reducing methane emissions is key to limiting global warming to 2 degrees Celsius or less above pre-industrial times to avoid the worst impacts of climate change.

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After decades of focusing on carbon dioxide, a greenhouse gas, policymakers have begun to recognize the threat posed by methane, and last year more than 100 countries signed a pledge to cut emissions. of methane by 30% below 2020 levels by 2030.

ISSUE OF EMERGENCY

After being largely ignored for decades, scientists now know that methane is far more potent than carbon dioxide as a short-term greenhouse gas, even if it only persists in the atmosphere for a decade before to decompose while the CO2 persists for centuries.

Scientists normally compare the warming effects of methane and carbon dioxide over a century, and on that timescale, methane is 28 times worse. Over 20 years, however, methane is 80 times worse, according to recent research.

It matters because the world is on track to exceed the 2015 Paris Agreement goal of limiting warming to below 2 degrees in just a few decades.

“If I thought we had 100 years to deal with climate change, I’d be much more relaxed about it,” said carbon footprint expert and author Mike Berners-Lee. “If you’re interested in the climate impacts we’ll experience in 2050…you’ll absolutely scream about methane emissions.”

The anticipated climate impact of methane is doubly worrying, as the world is closer than previously thought to crossing “tipping points” at which climate feedback loops kick in for self-perpetuating global warming. .

A study in september have suggested that some of the events that could trigger these feedback loops, such as the collapse of the Greenland ice sheet or the melting arctic permafrostare imminent.

WHERE IS THAT FROM

Three-fifths of estimated global methane emissions come from human activity; the rest from natural sources such as wetlands.

Of man-made emissions, two-thirds come from livestock and fossil fuels, with the remainder coming largely from waste decomposition as well as rice cultivation, Climate and Clean Air Coalition the data shows.

But the transmitters haven’t kept good records, and scientists trying to improve them over the past decade have had a shock.

“Everywhere we looked, methane emissions turned out to be higher than what the agencies said they should be,” said Robert Jackson, who was lead author of the September dots study. of climate change. “That was the case with oil and gas fields, landfills and feedlots.”

While scientists can accurately measure the level of methane in the atmosphere, understanding where it comes from is crucial for policymakers looking to impose regulations that reduce emissions.

WORSE THAN COAL?

Oil companies and nations are pushing for natural gas to be a “transition fuel” to renewables as the world transitions to clean energy to fight climate change. Their argument: the combustion of natural gas emits half as much carbon per kilowatt as coal.

But factor in gas industry leaks from rigs, pipelines, compressors and other infrastructure, and those gains can quickly be wiped out.

“There is a break-even point in the amount of methane leaking for … natural gas (to be) actually worse than coal for the climate,” said Sam Abernethy, co-author of the September study.

Governments around the world, including the United States, are mandating the oil and gas industry to find and repair leaks after studies showed that leaks in the industry were a huge problem.

The European Union recently approved the labeling of certain natural gas projects as “green” in a major boost for the industry.

Read more:

What do we know about the leaks from the Nord Stream gas pipeline?

EXCLUSIVE – Mexican regulator has no record of Pemex reporting methane leak

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Reporting by Tim Cocks in Johannesburg; Editing by Lisa Shumaker

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Teresa H. Sadler