> That said, fossil fuels are nowhere near to depletion and may well last for centuries. They ARE getting more expensive (see U.S shale oil in the last decade)

> That said, fossil fuels are nowhere near to depletion and may well last for centuries. They ARE getting more expensive (see U.S shale oil in the last decade) because the best spots are always mined first. Once gone you have to dig deeper and harder and use increasingly more complex and expensive methods to extract it. At some point you will get negative return on energy - so even if it is there it will be wasteful to extract.