A few weeks back, the Atlantic ran a story provocatively entitled ""What if We Never Run Out of Oil?". The long and short of the 11,000 word article is that methane hydrates (ice crystals of methane and water that form under high pressure) litter the coastal ocean floors, and if the technology could be developed to recover them, we could see a future of abundant energy. (i.e., retrieve the icy-solid hydrates, bring them to the surface and you have methane gas separating itself from the water just from the drop in pressure.) The author is going so far as to suggest that a New World Order may arise, one freed from the petroleum-based wealth that we currently live under.
I'm almost old enough to remember the promise of nuclear power: "Energy too cheap to meter!", so I'm pretty skeptical that we will never run out of oil. But at the same time, I can assure you in the strongest words possible that we will be using oil for far longer than most people imagine.
I've had only a few direct dealings with the oil industry so far, but one situation never ceases to amaze me. Deep-sea oil drilling rigs are currently being rented out for $1 million PER DAY. It can takes weeks to drill such a well, and those are all sunk costs (sorry about the pun) before the company recovers the first barrel of oil. But have you ever heard of any oil company not wanting to spend the money on another offshore well? Are the oil companies saying "No Mas!" to offshore drilling or "Drill Baby Drill!"? There are an endless supply of companies willing to take that million dollar a day bet.
Compare this to the alternative energy sources being proposed. Is any one company investing in solar at a million dollars a day? (Not SELLING solar panels at a millions dollars a day, BUYING them.) Or wind? There are dozens of companies doing that in oil all around the world.
There is nothing that is going to stop this train, short of the G20 agreeing on uniform and massive carbon taxes with no exceptions, and even at that, you might need to expand that to the G35 or G50. If you think that alignment is going to happen, then you would fall for the "too cheap to meter" line too.
The only time the global economy will stop using oil is when we truly run out of oil. But if you think you are going to see this anytime soon, just remember that you are betting against a whole lot of smart engineers, not only in the US, but around the world. Those same engineers are why we now have fracking and oil from the Canadian tar sands. Those energy sources were known for decades, but lacked the technology to properly access them. Do you really want to bet that engineers are going to let a few thousand feet of ocean water stand between them and a new energy source? Those depths haven't stop the oil drillers and it won't stop anyone else.