Human overpopulation (or human population overshoot) is the idea that human populations may become too large to be sustained by their environment or resources in the long term. The topic is usually discussed in the context of world population, though it may concern individual nations, regions, and cities.
Since 1804, the global living human population has increased from 1 billion to 8 billion due to medical advancements and improved agricultural productivity. Annual world population growth peaked at 2.1% in 1968 and has since dropped to 1.1%. According to the most recent United Nations' projections, the global human population is expected to reach 9.7 billion in 2050 and would peak at around 10.4 billion people in the 2080s, before decreasing, noting that fertility rates are falling worldwide. Other models agree that the population will stabilize before or after 2100. Conversely, some researchers analyzing national birth registries data from 2022 and 2023—which cover half the world's population—argue that the 2022 UN projections overestimated fertility rates by 10 to 20% and were already outdated by 2024. They suggest that the global fertility rate may have already fallen below the sub-replacement fertility level for the first time in human history and that the global population will peak at approximately 9.5 billion by 2061. The 2024 UN projections report estimated that world population would peak at 10.29 billion in 2084 and decline to 10.18 billion by 2100, which was 6% lower than the UN had estimated in 2014.