Overview
- A University of Milan paper published May 26, 2026, tested a new mathematical model against about 12,000 years of population data and reproduced major historical growth patterns including the industrial boom and slower post-1970 growth.
- Using that model the authors ran a deliberately conservative worst-case scenario in which Earth’s sustainable carrying capacity abruptly falls to roughly two billion people and found the global population could fall to about half its current size by around 2064.
- The researchers identify plausible triggers that could impose such an abrupt carrying-capacity limit: severe climate breakdown, a large pandemic, wide-scale conflict, major resource shortages, or sustained drops in fertility.
- The paper’s authors stress this result is an illustrative mathematical sensitivity test, not a forecast, and they report that their baseline analysis shows the present global trajectory does not imply imminent collapse; the outcome depends critically on the sudden carrying-capacity assumption.
- The study presses policy relevance by showing how fragile long-term demography can be to abrupt shocks and signals practical needs for stronger climate action, pandemic preparedness, food and water security, and demographic planning to protect living standards and social systems.