I just watched an Inconvenient Truth (yes, ok, late in the game...). Indeed, a very good documentary that I strongly recommend. A very useful evangelization tool! But the issue with global warming is that it has become a moral crusade when it's actually a scientific and engineering problem. The "inconvenient truth" is that if we don't solve the problem with engineering and technical solutions, we're irreversibly lost... It is now almost certain that our kids and grandkids will never enjoy earth as we did. They will survive with machines and artificial environments until critical resources will be missing or become unaccessible. Yes, they will ask us why we haven't done anything.