Great visual as well for understanding why anybody with a marginal cost of production for a barrel of oil <$20 (or whatever oil is trading for at a given moment along with the profit they consider reasonable / essential), is incented to pump and sell all they can, right now. The overwhelming pile of already proven reserves are unburnable.
In this context, any barrel of oil that can be sold today for $30, but instead the producer chooses to curtail that production can be reasonably viewed as a barrel of oil that the producer has decided it will not sell, and that's an asset they will not realize. Admittedly, it's really a barrel at some point in the future, whether that is 5, 10, or 50 years, but it's still a barrel that somebody else will get to pump and sell. So prices are going to stay low, and that will drive higher cost marginal producers from the market.
