Downward Revision to EPA Estimates of Natural Gas System Methane Emissions
In April 2013, the Environmental Protection Agency (EPA) released its annual Inventory of U.S. Greenhouse Gas Emissions and Sinks with updated estimates for natural gas emissions. This analysis characterizes new estimates for methane emissions and the implications for the GHG profile of natural gas.
The new Inventory data affirms a low methane emissions profile for natural gas systems, as well as a declining trend in those same emissions. Among the key findings of the analysis:
· The effective natural gas emissions rate per unit of natural gas production is 1.5 percent. This emissions rate is lower than earlier estimates of 2.2 to 2.4 percent derived using data from prior EPA Inventories for 2009 and 2010.
· The EPA revised its estimates of natural gas system methane emissions downward 33 percent for 2010, from 215.4 million metric tons of carbon dioxide equivalent in the 2012 Inventory to 143.6 MMTe in the 2013 Inventory.
· The long-term trend for methane emissions from natural gas systems is downward. Annual methane emissions have dropped 10 percent since 1990 and are 17 percent below the all-time peak set in 2007.
· Distribution system methane emissions have dropped 16 percent since 1990, even as the industry added nearly 300,000 miles of distribution mains to serve 17 million more customers, an increase of 30 percent in both cases.
· Expanding natural gas use provides a demonstrated path for reducing greenhouse gas emissions now and well into the future. Natural gas use produces far fewer GHG emissions than coal or oil on an energy-equivalent basis, an advantage further enhanced by the efficient use of natural gas in home appliances and industrial processes.
Contact: Richard Meyer, Energy Analyst, Policy Analysis (202) 824-7134
Full Report: Finding the Facts: What the EPA Greenhouse Gas Inventory Says about Methane Emissions from Natural Gas Systems (Energy Analysis 2013-02)