In early December, the Commonwealth Club of California hosted a discussion on climate change. Three science professors, including Michael Mann, author of "The Hockey Stick & the Climate Wars," examine the politics of environmental monitoring. Then James Hansen, head of NASA's Goddard Institute for Space Studies and winner of the Stephen Schneider Climate Science Communications Award, speaks about predictions he has made regarding climate-related disasters such as "Super Storm Sandy." Mr. Hansen is the author of "Storms of My Grandchildren."