Public opinion on climate change has shifted dramatically over the past 20 years, thanks to intense media coverage about global warming - coverage that, for better or worse, shaped both popular attitudes and the national political debate. Social Scientist Jon Krosnick of Stanford University argues that Americans' perceptions of climate change were severely distorted for years because so many journalists portrayed global-warming research as a heated argument between rival factions instead of what it actually was: namely, a growing body of shared knowledge. Krosnick’s analysis is an eye-opening look at how Americans know what they know, and why they believe what they believe. Program also includes an interview with National Medal of Science winner Daniel Kleppner. From the Series:Frontier