It is not just a question of limited resources. We will run out of oil one day.
Bio-fuels may do more harm than good as land previoulsy use to grow food is turned to growing bio-fuels. Clearance of tropical rain forests in order to grow palm oil is a major problem.
We could go nuclear but even uranium isn't limitless. We may be able to use nuclear fusion at some point in the future but although that may produce less CO2 we have a stack of other environmental problems to contend with.
Some have highlighted how quickly anarchy could arise and I agree. We think of society as being stable but there is no question this can break down extremely quickly.
This world as we know it will end one day. The question is when, and will mankind be able to shutdown in an orderly way?