[joe_the_user]

Not to be a broken record on HN, but I've often said--and I'll repeat here--that I don't believe altruism will solve greenhouse gas emissions and global warming: it'll only be solved when it becomes economic to do so.

The term "economic" can mean a lot of things. Solar and Wind can be cost-effect replacements for many uses of fossil fuel. With some regulations and transformation of daily surplus energy to other forms, you could get an economy with energy costs similar to the present and low carbon usage. So if "economic" just means, idk, works in an economy, then it's essentially not an important barrier (except the state should finance it's efforts with a graduated income tax and not a visibly-punishing measures like carbon or at-the-pump taxes, instead just making some things eventually prohibited but cushioning the blow for those poor or industries want to preserve).

But if by "economic", you mean the economy has to just do what it "wants" with no intervention at all, well we'll not only suffer the disasters of global warming but also unbridled pollution.