The Age of Oil Is Coming to an End

For humanity to advance, we need a solid plan for replacing all the energy supplied by coal, oil and natural gas with clean, environment-friendly substitutes. Replacing fossil fuels is a much bigger undertaking than most people appreciate, and it will take decades. Wind and solar are a super important part of the solution, but they're only part of any realistic solution. How many years are left before energy derived from petroleum becomes prohibitively expensive is a matter of debate.