Hubbert linearisation (Rev #2)

This is what Wiki would call a stub to get things started. If you plot yearly (world) oil production (P) as a fraction of total cumulative production (Q), against cumulative production (that is, plot (P/Q) against Q), you get a plot that, after about 1980 looks linear and declining. Calculate the linear equation of that trend, solve the differential equation for P, and you get a logistic function that has a peak–the famous Hubbert’s peak.