The energy crisis has even die-hard environmentalists reconsidering it. Stewart Brand and Mark Z Jacobson square off over the pros and cons – a discussion that will make you think and might even change your mind. Since the counterculture 60s, Stewart Brand has been a critical thinker and innovator who helped lay the foundations of our internetworked world. At Stanford, Mark Z Jacobson uses numerical models to study the effects of energy systems and vehicles on climate and air pollution, and to analyse renewable energy resources.