dr. stephen t. mos def colbert b.f.a., dictated not read." (laughter) now i'll send this to jimmy using the late night talk show internal mail system. (audience reacts) (cheers and applause) (laughter) jimmy fallon. fallon, not kimmel. fallon. go! (laughter) he's slow now but once he takes off he's lickety-split. (laughter) we'll be right back. (cheers and applause) hey ladies. enjoying the film? of course not. because this is our movie. and dr pepper ten is our soda! it's only ten manly calories, but with all 23 flavors of dr pepper. it's what guys want. like this... catch phrase! so you can keep the romantic comedies and lady drinks. we're good. (cheers and applause) >> stephen: welcome back, everyone. thank you. my guest tonight founded www.350.org to fight global warming. he must be winning because it's kind of chilly out. please welcome bill mckibben. (cheers and applause) hey, bill, thanks for coming back. all right, firm grip, man. all right, sir, i have had you on the show. i know who you are. let me explain to these people the troubl