Based on a polynomial curve fit of happiness and life expectancy to per capita footprint, the steepest increase in population growth corresponds to the period since adjusted power first cleared 50, in the 1920s. Adjusted power leveled off until the 1960s, when it began a drop that corresponded to a slowing of population growth. There was a leveling of adjusted power around 45 between 1980 and 2000, followed by resumption in the decrease that I project will end about 10 years from now at about 40, when population growth will reach zero. Beyond that point, there are broadly two possible futures.
In the most unlikely scenario, driven by a lack of energy the population will drop to zero or near to it. The other scenario involves a drop in population, accompanied by increase in ideality and power (likely a result of the drop, because more resources will be available to the survivors – which they won’t be able to effectively use because of the lack of people for processing and distribution).