Ultimately, change this drastic, to the point where it threatens the sovereignty of every free nation, only comes about in the face of global catastrophe. Nobody knows how far away Global Warming is, and until that point, many nations do not want to lose their comparative advantages in these tough economic times. The US will not agree to a single measure limiting their economy (even if it is clearly in the best interest of the global environment) until every other country agrees to do the same (China).