I actually think capitalism and free markets are the most viable solution. The problem is "short-sighted" capitalism that focuses on quarterly "hand to mouth" profits as opposed to people seeing the long-term business opportunities that lie in pivoting to renewables. As much as I detest Elon Musk, I think making the eco-friendly option cool and desirable for reasons beyond environmental impact is one of the best ways to encourage growth towards a more eco-friendly society.