Thom goes over the basics of what global warming is, what's causing it, and how we can stop it with climate scientist Michael Mann, author of the book “Dire Predictions: Understanding Climate Change.” For more information on the stories we've covered visit our websites at thomhartmann.com - freespeech.org - and RT.com. You can also watch tonight's show on Hulu - at Hulu.com/THE BIG PICTURE and over at The Big Picture YouTube page. And - be sure to check us out on Facebook and Twitter!