Expanding estimates of North America’s supply of accessible shale gas, and more recently, shale oil, have been trumpeted in many circles as the most significant energy resource development since the oil boom in Texas in the late 1920s. How large are these resources? What challenges will need to be overcome if their potential is to be realized? How will they impact U.S. energy policy?

To address these questions, the Belfer Center for Science and International Affairs and two of its programs ― the Environment and Natural Resources Program and the Geopolitics of Energy Project ― convened a group of experts from business, government, and academia on May 1, 2012, in Cambridge, Massachusetts. The following report summarizes the major issues discussed at this workshop. Since the discussions were off-the-record, no comments are attributed to any individual. Rather, this report attempts to summarize the arguments on all sides of the issues.