I think greed, selfishness and people truly inconsiderate happens on a greater scale than what we imagine with factoring into as an issue with the problem of global warming. I guess my scepticism is from considering the forgoing, before thinking of global warming and then thinking of other problems humanity faced (where people are concerned with their daily lifestyle continuing or improving).
Global warming is somewhat unique in the list of known problems when I think about it. I assume it will be too late, before people start being truly effected and to the point they act on something other than promoting public awareness. I've been living a lifestyle where I always walk to work & back. I don't own a car and I somewhat imagine similar steps need to be taken on a larger scale. I'm doubtful people will go from being knowledgable to acting. I have less faith on corporations and laws changing so they must act if they even care about being fined.