In the vast web of natural gas pipes beneath America’s streets, leaks are a persistent challenge. In addition to wasting a source of energy, leaked natural gas (which is mostly methane) is a powerful greenhouse gas and a significant contributor to climate change. The Environmental Defense Fund (EDF) and Google Earth Outreach have joined forces to find an efficient way to find and assess leaks under our streets. They are exploring the potential of new sensing and analytical technologies to measure key environmental data, and to make that data more widely available. The initial project uses sensors attached to Google Street View cars to create detailed maps of places where natural gas is leaking from utility pipes under city streets.