A large stormwater wetland at Wade Park near Wilmington, NC. (Contributed photo)

NC - North Carolina's wetlands emit lots of climate-warming methane gas. Is that bad?

When Duke Energy unveiled its plans to meet North Carolina's aggressive carbon-cutting goals, attention quickly focused on the utility giant's plan to replace much of the energy produced by its pollution-spewing coal-fired power plants with new natural gas-powered facilities.

The reason was while natural gas is a cleaner-burning fuel than coal, it is still a fossil fuel that releases climate-warming greenhouse gases, namely methane, into the atmosphere through the burning of the gas and leakages from pipes and the plants themselves. Duke said natural gas offered a cleaner way than coal to provide a reliable, affordable and secure power source to its customers. Environmentalists argued it was simply replacing one fossil fuel with another and locking North Carolina and its customers into a "dirty" energy future for decades to come when renewable energy sources could meet the power need in a cleaner, cheaper way.

Methane has a much bigger impact than carbon dioxide on global warming − an impact 25 times greater, according to researchers. Since pre-industrial times, increases in atmospheric methane have contributed to a quarter of the climate-warming effect from greenhouse gases.

That's prompted increased efforts to control methane releases from sources like landfills, agriculture and fossil fuels, including natural gas plants. Many scientists also are studying ways to remove methane from the atmosphere. That's because methane is 81 times more potent in terms of warming the climate over the first 20 years after its release, and about 27 times more potent over a century, according to two 2021 Stanford University-led studies.

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Natural methane pumps

But there's a dirty little secret about methane that can be seen all across North Carolina, especially in the boggy and wet eastern portions of the state. Natural wetlands emit between 30% and 40% of global methane emissions. The water‐logged soils in wetlands are ideal for producing methane as microbes in the soil decompose organic matter like dead plants, and the patterns and intensity of these emissions are likely to increase as the planet warms and gets wetter in many places, according to the U.S. Geological Survey.

This means that global warming is driving greater wetland methane emissions. This process is called the “wetland methane feedback”.

According to the state's 2022 greenhouse gas inventory report, methane emissions accounted for approximately 11% of North Carolina's total greenhouse gas emissions.

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