A new mathematical model predicts the world’s human population will crash by 2064 if global environmental crises intensify

The global population could halve as early as 2064 if global environmental crises intensify, a physicist at the University of Milan in Italy has hypothesised.

Alessio Zaccone’s paper titled Global population crisis scenarios predicted by a general nonlinear dynamical mode, has been co-authored with his late colleague Kostya Trachenko from Queen Mary University of London.

The paper proposes a surprisingly simple nonlinear mathematical equation that unifies 12,000 years of human population growth and points to stark possible futures if global environmental crises intensify.

“Different growth regimes since the early Neolithic until the present can be interpreted within a single nonlinear rate-feedback equation in appropriate limits. These include the well-known Malthus (exponential) and Verhulst (logistic) growth laws, as well as von Foerster-type hyperbolic growth as a controlled low-order truncation,” Zaccone wrote in an article published on the science aggregator portal Phys.org.

“The proposed framework provides a compact analytical setting to explore future scenarios, including a deliberately conservative, worst-case illustration in which the global population could halve as early as 2064 if carrying-capacity constraints became abruptly active today,” the abstract of the paper notes.

“Under a deliberately conservative worst-case assumption that Earth’s sustainable carrying capacity suddenly dropped to around 2 billion people, our model predicts a rapid global population decline, with humanity potentially halving by around the year 2064,” writes Zaccone.

Interestingly, the simple nonlinear differential equation had originally been used by Zaccone and Trachenko in the context of the physics of disordered systems.

“In the article we stress that this is not a forecast, but rather an illustrative mathematical scenario intended to show how sensitive population dynamics may be to abrupt environmental or societal changes. We emphasize that the current trajectory remains relatively stable and does not imply imminent collapse,” he concludes.