IMO Solar and wind are nice suplements, best suited for small and remote loads, until we have nuclear alternatives (like fusion), in the near term we will need coal and nuclear fission, we can burn coal without excess pollution, I beleive this carbon idea is a fad, and biofuel is a small niche market, practical for people who have resturants or factories with deep friers, unless you can start with waste oil it doesn't make sense. The Earth has changed many times through out history, man's contribution to carbon is only a small part, the geological record shows cycles of warming and ice ages long before industrialization -- the Earth isn't dependant on what man does, it is the other way around.