Usage figures vary quite a lot, depending on which source you use.
I was being conservative, it doesn’t affect the endgame of our future very much. Nor does it affect the veracity of my article. Collapse of oil supply will have a certain result. Accepting the truth of it is a matter of personal choice — I don’t attempt to put a date on it.
54 years is a matter of dividing quantities by annual consumption. It takes no account of wars to grab what’s left. (these are certain)
Oilwars will increase as supplies run down. If you have pay an army to protect your oilfields, then the cost shoots up. And becomes prohibitive.
Same applies to ‘proven reserves’.
The problem is not the amount of ‘reserves’ in the ground, but the energy-cost in extracting it.
A barrel of oil has a fixed calorific value in terms of usable energy. No form of ‘technology’ can change that.
.Early oilwells gave an energy return EROEI of 100:1
Now the best oilwells return 20:1. Fracked wells/tarsands give maybe 6 : 1. Which means fracked well production is supported by conventional well production.
Which explains why fracking fields run at a loss.
The amount of ‘reserves’ is irrelevant. When return drops lower than about 10: 1 at best, our lifestyle will start to break up. (see EROEI chart above), because our civilisation is dependent not just on oil, but on the energy extracted from cheap surplus oil. (Most can’t grasp that).
As the cost of oil extraction falls towards 1:1, oil will stay in the ground, no matter what “reserves” there are. (we can never actually get to 1:1, civilisation will collapse long before then)