A new study featured on Nature.com indicates that natural gas drilling is much more damaging to the environment than the public has been led to believe, with losses as high as 9 percent demonstrated at a gas drilling site in Utah.
Natural gas is mostly methane, which is a greenhouse gas with 72 times the Global Warming Potential (GWP) of carbon dioxide on a 20-year time horizon. The U.S. Environmental Protection Agency (EPA) estimates that only 2.4 percent of gas is lost into the atmosphere during production, and a Princeton University study has concluded that natural gas is cleaner to use than coal as long as the leakage rate is not higher than 3.2 percent.
The latest study by researchers for the National Oceanic and Atmospheric Administration (NOAA) and the University of Colorado in Boulder found a leakage rate of 9 percent at a Utah gas field. This follows an earlier Colorado study that determined a leakage rate of 4 percent.
If those numbers provide an accurate picture of how much methane is being lost into the atmosphere during drilling, then natural gas is harming the environment more than other fuels like oil and coal. Methane emissions from natural gas also continue during distribution, and a recent article by the Conservation Law Foundation indicates that natural gas pipelines are causing "enormous environmental consequences."
At an American Geophysical Union (AGU) meeting in San Francisco in December, the NOAA research team reported preliminary results from a field study in the Uinta Basin of Utah suggesting a 9 percent rate of methane leakage. "That figure is nearly double the cumulative loss rates estimated from industry data," Nature wrote.
"We were expecting to see high methane levels, but I don't think anybody really comprehended the true magnitude of what we would see," NOAA researcher Colm Sweeney told Nature.
The results build on those of the earlier Colorado study in the Denver-Julesburg Basin, led by NOAA scientist Gabrielle Petron. That study relied on pollution measurements taken in 2008 on the ground and from a nearby tower, and estimated a leakage rate that was about twice as high as official figures suggested, Nature reported.
In a related matter, law enforcement and environmental officials in six states recently urged the EPA to take new action to control methane emissions related to natural gas drilling. They said they intend to sue the EPA unless it establishes standards for new sources of methane and guidelines for existing sources.
"EPA has determined that emissions of this potent greenhouse gas endanger public health and welfare," Connecticut Attorney General Jepsen said in a statement. Connecticut joins Delaware, Maryland, Massachusetts, New York, Rhode Island and Vermont in the effort.
To read the article on Nature.com, click here.
To read a Hartford Courant article about the state actions on methane emissions, click here.