World Population Day: UN projects peak of 10.3 billion by 2080s as Germany shrinks

8.3 billion and counting

As the world marks World Population Day on July 11, the United Nations estimates the global population at around 8.3 billion people, a milestone that dates back to the symbolic threshold of 5 billion reached on the same day in 1987. The number continues to rise, driven by large cohorts of women entering childbearing age. Frank Swiaczny, a researcher at the Federal Institute for Population Research (BiB), notes that while fertility rates have fallen sharply, population momentum still pushes the total upward.

A turning point mid-century

The current growth trend is projected to reverse later this century. UN forecasts suggest that the world population will peak around the mid-2080s at approximately 10.3 billion people. After that, the global total is expected to begin a gradual decline. This inflection point marks a turning point for humanity's demographic trajectory.

Germany's shrinking population

Germany has already passed its own peak. At the end of 2025, the country's population stood at 83.5 million, a decline of 0.1 percent compared to the previous year, according to the Federal Statistical Office. Net immigration was insufficient to offset the birth deficit. Swiaczny highlighted that rising life expectancy is also reshaping the demographic structure, though it does not halt the overall shrinkage.

More and more people today are reaching old age due to better living conditions and medical care.

Fertility decline and aging

The global fertility rate has dropped from roughly four children per woman in the mid-1970s to about 2.2 today. Despite this steep decline, the world population continues to grow because women born during earlier high-fertility periods are now in their childbearing years, a phenomenon known as population momentum. Swiaczny explains that once the number of potential mothers decreases, the total number of births will start to fall. Combined with rising life expectancy, which is adding more older people, many societies face a future with fewer young workers and more retirees.

Growing vs. shrinking regions

Demographic trends are diverging sharply across the world. According to UN data, 63 countries and territories, including Japan, Russia, and China, have already seen their populations shrink. China alone could lose more than half of its current inhabitants by the end of the century. In contrast, 126 countries, primarily in sub-Saharan Africa and parts of Asia, are expected to continue growing until at least 2054. Nations such as the Democratic Republic of the Congo, Nigeria, and Somalia may even double their populations between 2024 and 2054.