You will find capitalism in a prison or in a refugee camp. People will invest some capital in a shady way to buy a carton of cigarettes, and boom the market is open and there are profits to be made. No matter what system purports to be in place, capitalism is going to happen since the pursuit of self-interest is inherent in human nature. It was around before fossil fuels, and will continue afterwards because people don't know any better. If you think they can be retrained somehow, merely take a gander at the People's Republic of China. No one had to teach them how to become capitalists and love luxury again.

There are many, many territories on Earth where fossil fuels can't be explored or extracted because laws say that can't be done in consideration of environmental or territorial whatevers. Laws can and do change all the time. It's not like the fuels aren't down there.