Comment by fwipsy

Your assumptions are equivalent to the "big tank" model. You assume that there's a fixed amount of petroleum, we know where all of it is, and we'll extract all of it. My point is that increased costs of extraction will push us away from petroleum before we reach a hard limit. Also, we could discover more petroleum -- you specify "known reserves" but it seems unlikely to me that we've really found all of it. (Not an expert though!)

Personally, I hope we transition to green energy sooner rather than later, but I think that these predictions are overconfident. A lot more will change in 50 years than in 4.