The Center on Global Energy Policy hosted a presentation by Dr. Steven Hamburg (Chief Scientist) and Mark Brownstein, (Associate Vice President & Chief Counsel, US Climate and Energy Program) of the Environmental Defense Fund (EDF). Hamburg and Brownstein presented the findings of a new study, published Monday in the Proceedings of the National Academy of Sciences, that examines sources of methane emissions from shale gas production sites across the U.S. The study, conducted by scientists at UT-Austin and executed in close collaboration with nine oil and gas companies and EDF, finds -- among other things -- that natural gas sites release 0.42 percent of methane produced. This finding is in line with EPA's current emission inventory estimate for the production segment of the supply chain, though the study also found emissions from specific phases of production are likely to be higher or lower than EPA estimates. Hamburg and Brownstein discussed the study's findings and methodology as well as its implications for shale gas policy and the role of natural gas in our energy future. A moderated discussion followed. This event was open to the press.