The most important question coming out of my analysis of energy and population is whether there is in fact a maximum cumulative amount of energy that humans can produce before our population drops. This is another way of asking another question I’ve brought up before: Is there a maximum amount of resources we can consume before we pay the ultimate price?
When population is plotted as a function of either cumulative ecological footprint or cumulative production of energy, the graphs (of normalized values) are practically indistinguishable from each other. They show the same disturbing pattern: a gradual decrease in growth of population, which all curve fits from second to sixth order identify as the leading side of a downward-facing parabola.
For both footprint and energy, the peak in population occurs when the amount accumulated since 1990 reaches 43 times what was accumulated in 1991 and the population is 7.13 billion people. I’ve chosen 1990 as a reference point because, as I’ve noted elsewhere, it is the year environmental experts believe that humans started using more resources than our planet could replenish (the ecological footprint equaled one Earth). The population reaches zero when the total accumulated amount exceeds 89 times the 1991 amount. We are currently over 19.