New drilling technologies and the discovery of significant new natural gas reserves in the U.S. are changing the landscape of energy production. As methane becomes plentiful and cheaper, it is likely to account for an increased share of energy production both in the U.S. and worldwide. Understanding the environmental implications of this shift is an important step for evaluating current and future regulatory regimes and potential policy responses to the “shale revolution.” This grant supports a series of independent research projects coordinated by the Environmental Defense Fund (EDF) that jointly aim to increase our understanding of the source and quantity of gas leaks by residential, commercial, and industrial end users of methane.  Led by Chief Scientist Steven Hamburg, EDF will bring environmental researchers from Harvard, Purdue, West Virginia University, and the University of Illinois together with engineers from the sensor industry and experts from the U.S. Geological Survey to launch a series of studies designed to measure how much methane gas escapes during its final stop in the distribution pipeline. Since methane is a more potent greenhouse gas than carbon dioxide, understanding the quantities emitted during end use is a crucial element in evaluating the potential climate impacts of a shift to increased reliance on gas. The work also has the potential to identify especially problematic, high-leak varieties of end use as topics worthy of further scientific attention. Grant funds provide research support, offset administrative costs of the project, and support efforts at synthesis and dissemination.