Birth Rate Decline
What the Chart Shows
- Population Peak: The population rises until ~2075-2085 (peaking at ~10.3-10.4 billion), then plateaus or slightly declines by 2100 as births fall below deaths.
- Birth Rate Drop: The crude birth rate continues its decline, reaching ~8 per 1,000 by 2100, reflecting a TFR of ~1.8, well below replacement.
- Decline Trigger: The population starts declining when the birth rate (and thus total births) can no longer offset deaths, projected around 2080-2085 in the UN medium scenario.
Caveats - Uncertainty: Projections depend on fertility trends, which vary by region. Policy interventions (e.g., pro-natalist policies) or unexpected events (e.g., pandemics, economic shifts) could delay or hasten decline.
- Regional Differences: Some regions (e.g., Africa) may grow past 2100, while others (e.g., Europe, East Asia) are already declining. Global decline hinges on when high-fertility regions like Africa align with global trends.
Conclusion Based on the chart and projections, global population decline due to falling birth rates is most likely to begin around 2080-2085, with some models suggesting as early as 2060-2070 if fertility declines faster. This shift will reshape economies, societies, and global resource demands. If you’d like a deeper dive into a specific region, scenario, or factor (e.g., immigration’s role), let me know!
Estimating When Population Might Decline The chart shows the crude birth rate dropping from 36.9 per 1,000 in 1950 to ~17 in 2025, while the population grew from 2.5 billion to 8.2 billion. To determine when the population might decline based on birth rates, we need to consider projections for when the global birth rate and total fertility rate (TFR) fall low enough to result in more deaths than births globally. Here’s the analysis:
- Current Trends:
- Global TFR is ~2.3 children per woman in 2025, slightly above the replacement level of 2.1 needed to maintain a stable population (assuming no migration and stable death rates).
- The crude birth rate (~17 per 1,000) is still higher than the crude death rate, so the population is growing, albeit more slowly than in past decades.
- Projections from UN and Other Sources:
- According to the UN World Population Prospects (2024 Revision), the global population is projected to peak around 2080-2086 at ~10.4 billion under the medium scenario. This assumes TFR continues to decline to ~2.1 by the late 2040s and further to ~1.8 by 2100.
- A population decline begins when the number of births falls below the number of deaths globally. The UN estimates this could happen around 2084 in the medium scenario, as the birth rate drops to ~12 per 1,000 by 2050 and continues falling, while death rates rise slightly due to aging populations.
- Some models, like those from the Institute for Health Metrics and Evaluation (IHME), suggest an earlier peak and decline (e.g., ~2064 at 9.7 billion) if fertility declines faster than expected, as seen in countries like South Korea (TFR 0.58 in 2024) or China (TFR ~1.0).
- Key Factors for Decline:
- Regional Variations: Sub-Saharan Africa’s high fertility (~4.0 TFR) sustains global growth, but even there, rates are falling (e.g., Nigeria’s TFR down from 6.4 in 2000 to ~5.0 in 2025). Meanwhile, over 60% of countries (e.g., Europe, East Asia) already have TFRs below replacement, experiencing natural decline without immigration.
- Aging and Death Rates: As populations age, death rates may rise (projected to ~11-12 per 1,000 by 2050), accelerating the point where deaths outnumber births.
- Tipping Point: Global decline is likely when TFR falls below 2.0 and stays there, expected around 2050-2060 in medium scenarios. Absolute births (~140 million in 2025) are projected to drop to ~126 million by 2100, per UN data.
- Estimated Timeline:
- Based on the chart’s trend of declining birth rates and UN projections, global population decline due to births falling below deaths is most likely to begin around 2080-2085 in the medium scenario. This assumes no major disruptions (e.g., policy changes boosting fertility or catastrophic events).
- In faster-decline scenarios (e.g., IHME’s low-fertility model), this could occur as early as 2060-2070, especially if economic pressures, climate challenges, or cultural shifts further suppress birth rates.
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