I saw it mentioned offhandedly, in a trade publication that wasn't trying to use it to support a position, that the consensus estimate is that roughly 1/2 of the world's oil reserves are gone. This includes the sum of reserves sitting under the arctic ice shelf and under the deepest portions of the Oceans, etc. Most of the easy to access reserves have been used. There is definitely an issue involving depletion of natural gas reserves from North America. There are however, significant reserves of natural gas in the Middle East and Asia, but the problem is that to get gas to the US you have to liquefy it by freezing before moving it which is extremely dangerous. Also, it is a southward suck. Mexico has almost no natural gas, who imports from the US. The US, then, has to import from Canada to supply it's "needs". As such, natural gas vs. oil makes an interesting spread on the depletion of local reserves vs. total reserves. Even so, there are still tons of working wells in the US extracting gas & oil, but they have to keep going deeper. I would imagine that before the world ends up in one of these doomsday scenarios, we will likely see natural gas price fluctuations increase exponentially, and you will see the announcement of several new handling plants for liquefaction in the US, where none have been built since the early 70's I believe. Until then I wouldn't worry about the end of the world. Also, keep in mind that the sheer volume of people in China who are becoming potential oil consumers on US-like levels may cause major price increases over the next few years, but more because of an increase in demand vs. decline in supply. I've seen estimates that crude oil might rise to $40/barrel. The 52 week low was around $24/barrel There are people working on using organic waste, like "animal byproducts" to produce oil. The process actually works, but the problem is doing it in any cost effective way. Talk about a PETA/Greenpeace nightmare! Soylent Unleaded.
Also, keep in mind tritium, aka Hydrogen-3, from the moon as a fuel source for fission reactors which would produce low toxicity waste products with a 12.5 year halflife! Astronaut Harrison Schmitt thinks it's a good idea!