How Can We Predict When a Population Will Double in Size? (2024)

As of 2017, the annual growth rate for the entire world is 1.053%. That means the human population on Earth will double from 7.4 billion in 66 years,or in 2083.

However, as previously mentioned, doubling time is not a guarantee over time. In fact, the U.S Census Bureau predicts that the growth rate will steadily decline and by 2049 it will only be at 0.469%. That is less than half of its 2017 rate and would make the 2049 doubling rate 149 years.

Factors That Limit Doubling Time

The world's resources—and those in any given region of the world—can only handle so many people. Therefore, it is impossible for the population to continually double over time. Many factors restrict doubling time from going on forever. Primary among those is the environmental resources available and disease, which contribute to what is called the "carrying capacity" of an area.

Other factors can also affect the doubling time of any given population. For example, a war can significantly lower the population and affect both the death and birth rates for years into the future. Other human factors include immigration and migrations of large numbers of people. These are often influenced by the political and natural environments of any country or region.

Humans are not the only species on Earth that have a doubling time. It can be applied to every animal and plant species in the world. The interesting factor here is that the smaller the organism, the less time it takes for its population to double.

For example, a population of insects will have a much faster doubling time than a population of whales. This is once again primarily due to the natural resources available and the carrying capacity of the habitat. A small animal requires far less food and area than a larger animal.

Source

• United States Census Bureau. International Data Base. 2017.