rate of natural increase

The rate of natural increase in a population is determined by the difference between its birthrate and death rate. This rate is a key component of population growth, alongside migration. Historically, human populations grew slowly due to high mortality rates. However, since the 18th century, advancements in sanitation, public health, and living standards have led to declining death rates and accelerated population growth, particularly in developing countries.12

While the highest known rate of natural increase for a national population was approximately 4.1 percent per year in Kenya during the 1980s, industrialized nations typically have much lower rates, often below 1 percent, and some even experience negative natural increase. Despite declining fertility rates globally, the human population continues to grow due to "population momentum," where a large youth population enters reproductive age. The world population reached 8 billion in 2022 and is projected to peak around 10.4 billion by 2080.134