I think your answer is most likely to be correct. Oil won't disappear today or tomorrow, but it's very hard to imagine the technology that needs to be developed

I think your answer is most likely to be correct. Oil won't disappear today or tomorrow, but it's very hard to imagine the technology that needs to be developed so that oil is still cheap and plentiful in 2100. BP has some good reports on this issue (http://www.bp.com/en/global/corporate/about-bp/energy-economics/statistical-review-of-world-energy-2013.html http://www.bp.com/en/global/corporate/about-bp/energy-econom...). If we don't solve the energy problem, there is a reasonable chance that humans in 2100 will have a worse standard of living than those today. Seriously.