Climate Sense: Concerns rise over methane and auto-emission rules

Methane is a powerful greenhouse gas, capable of trapping far more heat than the same amount carbon dioxide, at least in the short term. This week, I point you to some new studies regarding the release of methane and news about a potential showdown between state and federal governments over fuel-economy standards.

Methane, the primary component of natural gas, is not well understood by many people. Methane can absorb more than 100 times as much energy as an equal weight of carbon dioxide, experts say, but methane breaks down in the atmosphere over time, so the effect of releasing a ton of methane actually decreases as time goes on.

Graphic: Environmental Protection Agency

Methane’s “global warming potential,” or GWP, is said to be 28-36 times higher than CO2 when considering the effects over 100 years — so methane is regarded as a major contributor to climate change. Check out the explanation of GWP by the Environmental Protection Agency.

Sources of methane are widespread — from vegetation naturally decomposing in wetlands to incidental releases during natural gas production and transport. Figuring out the amount of methane coming from various sources has been a puzzle for climate scientists.

Item 1: Oil and natural gas production increases GHG emissions

A new study led by NASA researchers and published in Nature Communications has come to the unwelcome conclusion that a dramatic increase in atmospheric methane can be linked to the increased production of petroleum in the U.S. Writer Sharon Kelly explains in EcoWatch how the study helps to solve the mystery of the “missing methane.”

“The sharp increase in methane emissions correlates closely with the U.S. fracking boom,” Jim Warren, executive director of the climate watchdog group NC WARN, was quoted as saying. “Leaking and venting of unburned gas — which is mostly methane — makes natural gas even worse for the climate than coal.”

The video, shown here, is produced by the Environmental Defense Fund, an advocacy group, but it provides a good representation of where methane leaks may occur.

Item 2: Methane leaks not easily identified in some regions

Methane leaks from oil and natural gas production are not only bad for climate change but they are a loss of potential revenue for petroleum producers, so nobody wants leaks. Since 2008, the industry in the United States has been required to use optical gas imaging technology to detect methane leaks, as described by Sabrina Shankman of Inside Climate News.

But the current technology for detecting such leaks does not function reliably when the temperature gets well below zero, as it often does in the oil fields around Prudhoe Bay, she says, adding another example where methane leaks may go undetected and unreported.

Meanwhile, the EPA under the Trump administration has been moving to reduce leak-detection requirements for oil and gas fields, although they are facing challenges in court, Sabrina reports.

Item 3: Arctic bogs could produce spiraling methane releases

Increasing rains in the Arctic could hasten the pace of spring thawing, releasing more and more methane from the permafrost, according to a new study in Geophysical Research Letters.

“At a thawing wetland complex in Interior Alaska, we found that interactions between rain and deep soil temperatures controlled methane emissions,” the authors reported. “In rainy years, recharge from the watershed rapidly altered wetland soil temperatures, warming the top ~80 centimeters (31 inches) of soil in spring and summer and cooling it in autumn. When soils were warmed by spring rainfall, methane emissions increased by ~30 percent.”

“The findings are cause for concern,” writes Phil McKenna of Inside Climate News, “because spring rains are anticipated to occur more frequently as the region warms. The release of methane, a short-lived climate pollutant more potent than carbon dioxide over the short term, could induce further warming in a vicious cycle that would be difficult if not impossible to stop.”

Item 4: Sightline series examines methane issues

Sightline Institute, a Northwest organization that promotes sustainability by offering “practical vision and innovative thinking,” has produced a three-part series on the methane issue written by Tarika Powell:

  1. Calling natural gas a ‘bridge fuel’ is alarmingly deceptive
  2. Methane’s 20- and 100-year climate effect is like ‘CO2 on steroids’
  3. Studying full methane life cycle critical to Pacific Northwest policy

The discussion about methane is part of an ongoing series (now 46 articles) called “Fracked fuel and petrochemical projects in the Pacific Northwest,” in which Sightline profiles the risks of projects that would produce or transport methanol, zylene, liquefied natural gas, liquefied petroleum gas and other products in the region.

Item 5: Showdown coming on California emissions standards

This week, Reuters and other news organizations reported that the Trump administration has formally stopped negotiating with California officials about federal plans to roll back national fuel-efficiency standards for automobiles.

For years, California maintained standards stricter than those of the federal government to reduce pollution and cut back on greenhouse gas emissions. At least 12 other states have adopted California’s standards, allowed under a special exemption from the EPA. Now that an exemption could be revoked, setting up a court fight.

Standards proposed under the Obama administration would require automakers to roughly double average fuel efficiency by 2025, but the Trump administration wants to freeze those standards at 2020 levels, saying further changes would raise the cost of vehicles to an unacceptable level.

“Climate Sense” is my attempt to share some of the important research, political developments, fascinating viewpoints or inspiring opinions that I come across during my reading. For a further explanation, read my first Water Ways post of 2019: “Climate Sense: I would like to share what I learn during this coming year.”

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