The amount of methane leaked from shale gas production has been massively overestimated according to a new study.

The study was authored by University of California Professor of Physics and Lawrence Berkeley National Laboratory senior scientist Dr. Richard Muller and his daughter Elizabeth Muller, a former policy adviser for the Organisation for Economic Co-operation and Development (OECD). It was published by the Center for Policy Studies, a free-market British Policy think-tank.

Natural gas is already replacing coal as a source of electricity, particularly in the United States, but concerns about possible methane leaks have slowed adoption of shale gas. The study shows that the amount of methane leaked is much smaller than previously believed, effectively debunking one of the most used environmental arguments against natural gas.

The study calculates that over 100 years an implausible 12 percent of the produced natural gas used today would have to leak in order to negate natural gas’ emissions advantage over coal. The best current estimates for the average leakage across the whole supply chain are below 3 percent, meaning that natural gas will produce less than half the warming of coal averaged over the 100 years of emissions.

Natural gas emissions also have a much shorter legacy than coal emissions, as after 100 years only 0.03 percent of leaked natural gas remains in the atmosphere, compared to 36 percent for remnant carbon dioxide from coal power plants.

“The transition from coal to natural gas for electricity generation has probably been the single largest contributor to the … largely unexpected decline in U.S. CO2 emissions” according to Berkley Earth and the Department of Energy. High efficiency natural gas plants reduce emissions of carbon dioxide by 63 percent while generating the same amount of power as the coal plants they replace.

Methane emissions are 28 to 36 times more potent as a greenhouse gas than CO2 over a 100 year time period according to the Environmental Protection Agency. However, according to the study warming from fugitive methane is actually minuscule compared to the amount of warming from carbon dioxide.

The study shows that natural gas will produce less than half the warming of coal over the 100 year time period.

“Environmentalists who oppose the development of shale gas and fracking are making a tragic mistake” Muller previously stated.

Environmental groups, such as The Sierra Club, previously supported natural gas as a so called “bridge fuel.”

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