According to researchers from the National Oceanic and Atmospheric Administration (NOAA) and the University of Colorado at Boulder, hydrofracking operations at a gas field in Utah leak 9% of the methane they produce.
These numbers are much higher than earlier, contested findings by the same scientists. In 2012, they measured a leakage rate of 4% at a gas field in Colorado.
From an article on the findings in the journal Nature:
"We were expecting to see high methane levels, but I don’t think anybody really comprehended the true magnitude of what we would see,” says Colm Sweeney, who led the aerial component of the study as head of the aircraft programme at NOAA’s Earth System Research Laboratory in Boulder.
Whether the high leakage rates claimed in Colorado and Utah are typical across the US natural-gas industry remains unclear. The NOAA data represent a “small snapshot” of a much larger picture that the broader scientific community is now assembling, says Steven Hamburg, chief scientist at the Environmental Defense Fund (EDF) in Boston, Massachusetts.
A debate over whether natural gas production will be a cleaner electricity source than coal has raged since researchers at Cornell University estimated methane emissions at up to 7.9%. The Colorado and Utah findings are the first to be based on field measurements.
Methane is a 20-times more potent greenhouse gas than carbon dioxide over a 100-year time period.
New York Attorney General Eric Schneiderman along with six other attorneys general plan to sue the federal government for failing to regulate methane emissions.
If lower estimates of around 2% leakage are accurate, then natural gas could be a climate-friendly replacement for coal. If the higher findings are correct, then the opposite could be true.