I think the thing to remember is that we don't have 'dirty' energy supplies because we don't know any better, we have them because they are plentiful, relatively cheap, and controlled by a small number of hands that got control of them before we thought much about how dirty they are. There's a pretty big incentive (for them) to not switch over immediately to something much cleaner, so it's going to be a long-ish struggle -- but I think it's safe to say that there's an (electric!) light at the end of the tunnel.
In the mean time, some things that are happening will force their hand sooner:
- Like it or not, we're moving to an electricity-based economy; something like 20% of the energy input that results in GDP was electric 20 years ago, today it's more like 40%.
- It's getting increasingly difficult/expensive to maintain the carbon supplies where they are, geopolitically speaking, wink-wink.
- Markets are distributed: places like California have always been big enough and bold enough to do things like have their own air standards that are tougher than those put forward by the (US) Federal Government. Smaller countries (Canada, Sweden, France, Japan, et al) have realized that you don't have to have everyone lined up behind an idea before you do it -- you can do it yourself and get whatever benefit that comes from your piece of the pie.
- The next round of "small number of hands" are in the formation stages today; expect a nice fight between the old haves and the new haves ...
/jordan