Production over discoveries
An oil depletion trend line that should get more pub plots the monotonically increasing ratio of production over estimated discoveries as a function of time. I show this value for each past decade in the following table:
I find it portentous that the numbers look like they increase at a roughly exponential rate, but we know that can't keep going forever. At some point it needs to show an inflection point and start to level off and then creep back toward 1 -- which means that we use as much as we find. And although the current decade has not contributed its data point yet, the accumulated numbers have not yet budged from the previous decade. When we look back at the inflected curve, it will point out in hindsight the physical rationale behind what we see in purely economic terms -- i.e. plotting the production peak alone only tells half the story.