The recent 2026 buzz about the population halving by 2064 comes from a theoretical paper published in the journal Chaos, Solitons & Fractals by physicists Alessio Zaccone (University of Milan) and the late Kostya Trachenko.
- What it actually says: The researchers adapted a non-linear mathematical equation (originally used in materials physics for disordered systems like glass) to map 12,000 years of human population growth.
- The Catch: The model does not forecast a collapse. Instead, it ran a deliberately conservative, absolute worst-case scenario assuming that Earth’s sustainable carrying capacity abruptly dropped to just 2 billion people today due to simultaneous, maximum-severity catastrophes (like a severe nuclear winter, total resource collapse, or an extreme climate failure). Only under this catastrophic simulation does the model show the population halving by 2064.
- The Authors’ Clarification: The physicists explicitly stressed that their paper is a mathematical tool to measure system sensitivity, noting that “the current trajectory remains relatively stable and does not imply imminent collapse.”
2. The 2020 Lancet Study: A Natural Demographic Shift
The year 2064 is highly significant in demography, but for a completely different, non-catastrophic reason. A landmark study published in The Lancet by the Institute for Health Metrics and Evaluation (IHME) used 2064 as its target timeline for a natural population peak.
- The Actual Projection: The study projected that the global population will peak at 9.7 billion in 2064 and then experience a gradual, steady decline to about 8.8 billion by 2100 due to rising female education and widespread access to contraception.
- Where the “Half” Metric Comes From: The Lancet study did not say the global population would halve by 2064. It predicted that by 2100, roughly 23 specific countries—including Japan, Thailand, Spain, Italy, and South Korea—could see their individual populations shrink by 50% or more as their total fertility rates drop well below the 2.1 replacement level.
Summary of Global Projections
To put it in perspective, major global institutions do not project a population crash by mid-century. Standard reference models track a much more stable curve:
| Source | Projected Peak Year | Peak Population | Target for 2100 |
| UN Population Division (2024 Revision) | ~2084 | ~10.3 Billion | ~10.2 Billion (Slow decline) |
| The Lancet / IHME Study | ~2064 | ~9.7 Billion | ~8.8 Billion (Gradual decline) |
| Zaccone-Trachenko Model (2026) | N/A (Simulation Only) | N/A | Halves to ~4 Billion only if carrying capacity drops to 2B today. |
Ultimately, unless humanity faces an unprecedented, total planetary catastrophe that destroys our resource baseline overnight, the Earth is not on track to lose half its population by 2064. Instead, we are looking at a thoroughly documented transition toward an aging global population and a flattening growth curve.
To understand more about the demographic shifts and the data underlying these mid-century projections, you can watch this analysis of the Lancet world population forecast. This video features an explanation from the United Nations’ Population Estimates section regarding how global power dynamics and workforces could change as populations peak and contract.
