Yes, that ego maniac of movies chickened out. He likes to threaten people a lot (like shooting them down in the street and wanting to fight them), but when a challenge - BY HIM - to debate Global Warming was accepted by some skeptics, he first went through Orwellian contortions to change the rules (all changes were accepted) before pulling out at the very last minute!
It seems the blow hards (the real source of AGW) are good about denying all the access to the facts and information, and a good and honest debate. I seem to recall that we do have a term for that.
Oh, yea - Super Chicken! I think the "green" movement is dying like an un-watered lawn in summer. They are turning yellow.