Dr. Roy Spencer is a much more credible source on climate change. Dr. Mann is not an impartial scientist. http://www.drroyspencer.com/
Bought and paid for explanation. Not an expert. Temperatures are not warming.
I've never seen the show before, and so I don't know how accommodating Bruce usually is with the views of his guests, but for whatever reason any objectivity on his part seemed to have the day off. (Someone should give him Montford's book--for perspective or punishment, depending on one's own views.) However, Bob did a good job with a more balanced line of comments and questions.