David Doniger and Myron Ebell talked about the National Oceanic and Atmospheric Administration report that 2012 was the hottest year on record for the contiguous 48 states and the second-worst for extreme weather such as tornadoes, wildfires and drought. Topics included natural variability and human intervention in the climate, temperature records in 2012, and long term climate and pollution projections. They also responded to telephone calls and electronic communications.