A population decline (or depopulation) in humans is a reduction in a human population size caused by short term events such as pandemics, wars, famines or other catastrophes, or by long-term demographic trends, as in sub-replacement fertility rate, or persistent emigration.
Even though short-term population shocks have caused terrible loss of life and human misery, sometimes lasting several centuries, over the long-term, stretching from prehistory to the present, this planet’s human population has continued to grow. However, current events suggest that this long-term trend may be coming to an end. Up until the beginning of the industrial revolution, global population grew very slowly. After about 1800 the growth rate accelerated to a peak of 2.1% annually in 1962; but since then, due to the world-wide collapse of the total fertility rate, it has declined to 1.1% today (2020). Long-term projections predict that the growth rate of the human population of this planet will continue to decline, and that by the end of the 21st Century, will reach zero.
An example of this emerging trend is Japan, whose population is currently (2015-2020) declining at the rate of 0.2% per year. By 2050, Europe’s population is projected to be declining at the rate of 0.3% per year.
Possible consequences of long-term national population decline can be net positive or negative. If a country can increase its workforce productivity faster than its population is declining, the results, both in terms of its economy, the quality-of-life of its citizens, and the environment, can be net positive. If it cannot increase workforce productivity faster than its population’s decline, the results can be mostly net negative.
National efforts to confront population decline to-date have been focused on the possible negative economic consequences and have been centered around increasing the size of the nation’s workforce and the productivity of its workers.
Many countries in Europe are faced with a huge net decrease in population and hence an increase in the average age of the working population. Some countries face the first large population reduction since the Black Death plague in the 14th century.