Energy Exchange

A new scientific study published today in the Proceedings of the National Academy of Sciences, coordinated by EDF, reports findings from the most comprehensive examination of regional methane emissions completed to date. Focused on Texas’ Barnett Shale – one of the nation’s major oil-and-gas-producing regions – the study uses a new, more accurate way to determine the total amount of methane escaping into the atmosphere from the region’s oil and gas production, processing and transportation.

The result is that methane emissions in the Barnett Shale are 90 percent higher than EPA’s inventory data would suggest.

This is just one of several recent studies showing a pattern of underestimating methane emissions in locations across the country. One big reason is that conventional inventories typically fail to accurately account for very large, unpredictable emissions from leaks, malfunctions or other problems. In the Barnett study, these were the source of a large share of total emissions.

Why Methane Matters

The higher emissions rate and the agreement among measurement methods represent an important step forward in our understanding of what it will take to mitigate those emissions. Methane is the main ingredient in natural gas, and a highly potent greenhouse gas, with over 80 times the 20-year warming power of carbon dioxide.

When methane leaks, the climate impact of using natural gas increases. In the case of Barnett Shale gas, based on emissions identified in the study, the climate impact is 50 percent higher over 20 years as compared to the use of natural gas in the absence of any emissions. Read More »

Methane emissions from vast oil and gas operations in the densely populated Barnett Shale region of Texas are 50 percent higher than estimates based on the Environmental Protection Agency’s (EPA) greenhouse gas inventory, according to a series of 11 new papers published today in Environmental Science & Technology.

The majority of these emissions are from a small but widespread number of sources across the region’s oil and gas supply chain. These emissions come from the sort of leaks and equipment malfunctions that are relatively easy to prevent with proper and frequent monitoring and repair practices.

The sprawling Barnett region, fanning out westward from the cities of Dallas and Fort Worth, contains about 30,000 oil and gas wells, 275 compressor stations, and 40 processing plants. It is one of the country’s largest production areas, responsible for 7 percent of total U.S. natural gas output.

Unpredictable, Widespread Sources Dominate Read More »

The everyday use of natural gas across the greater Boston area is resulting in much higher emissions of methane than previously thought, according to a study published this month in the Proceedings of the National Academy of Sciences. These emissions represent the waste of a valuable energy resource as well as an important source of greenhouse gas, since methane—the main component of natural gas—is 84 times more potent than carbon dioxide for the first 20 years it is in the atmosphere.

The reported emissions are more than two times higher than previously estimated using state emissions inventory data, with a yearly average loss rate from delivery and use of natural gas in the Boston urban region of 2.7 percent (with a margin of error of 0.6 percent). That’s enough natural gas to fuel about 200,000 homes each year.

While EPA data indicates that investments by many gas utilities in reducing leaks have made a difference, this study, led by scientist at Harvard University, demonstrates that the national statistics may mask significantly higher emissions in some parts of the country. Read More »