Projections of future global human population are traditionally made using birth/death trend extrapolations, but these methods ignore limits . Expressing humanity as a K-selected species whose numbers are limited by the global carrying capacity produces a different outlook . Population data for the second millennium up to the year 1970 was fit to a hyper-exponential growth equation, where the rate constant for growth itself grows exponentially due to growth of life-saving technology . The discrepancies between the projected growth and the actual population data since 1970 are accounted for by a decrease in the global carrying capacity due to ecosystem degradation . A system dynamics model that best fits recent population numbers suggests that the global biocapacity may already have been reduced to one-half of its historical value and global carrying capacity may be at its 1965 level and falling . Simulations suggest that population may soon peak or may have already peaked . Population projections depend strongly on the unknown fragility or robustness of the Earth ’ s essential ecosystem services that affect agricultural production . Numbers for the 2020 global census were not available for this study.