run out of coal (note 3), oil, and natural gas to burn. They're finite, so this is guaranteed to happen - the question is whether it happens before anything else

Running out is not likely to happen any time soon at expected usage growth rates. The cost of extracting coal, oil, and natural gas will (possibly) increase over time but new technologies may depress the price of each (see the current state of natural gas). The estimates for potentially extractable reserves gives a figure such that if ways are found to extract such reserves oil and coal will be in continual usage (at present growth rates) for over another hundred years in the future.

Further, there are ways of producing oil substitutes that become feasible as oil hits certain price points. As these get implemented large scale it is likely that economies of scale and incremental improvements will kick in so that even though there will still be oil being produced most ways that we currently use oil will be changed over to the new technologies. Oil just happens to be the lowest cost alternative currently but as demand increases and cost of production increase then the other alternatives will be used.