Current World Population and Future Projections

Urban Road and City Building of Hong Kong

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The world population has grown tremendously over the past 2,000 years. In 1999, the world population passed the six-billion mark. By March of 2018, the official world population had jumped over the seven-billion mark to an estimated 7.46 billion.

World Population Growth

Humans had been around for tens of thousands of years by the year 1 A.D. when the Earth's population was an estimated 200 million. It hit the billion mark in 1804 and doubled by 1927. It doubled again in less than 50 years to four billion in 1975.

Year Population
1 200 million
1000 275 million
1500 450 million
1650 500 million
1750 700 million
1804 1 billion
1850 1.2 billion
1900 1.6 billion
1927 2 billion
1950 2.55 billion
1955 2.8 billion
1960 3 billion
1965 3.3 billion
1970 3.7 billion
1975 4 billion
1980 4.5 billion
1985 4.85 billion
1990 5.3 billion
1995 5.7 billion
1999 6 billion
2006 6.5 billion
2009 6.8 billion
2011 7 billion
2025 8 billion
2043 9 billion
2083 10 billion

Concerns for an Increasing Number of People

While the Earth can only support a limited number of people, the issue is not so much about space as it is a matter of resources like food and water. According to author and population expert David Satterthwaite, the concern is about the "number of consumers and the scale and nature of their consumption." Thus, the human population can generally meet its basic needs as it grows, but not at the scale of consumption that some lifestyles and cultures currently support.

While data is collected on population growth, it is difficult for even sustainability professionals to understand what will happen on a global scale when the world's population reaches 10 or 15 billion people. Overpopulation is not the biggest concern, as enough land exists. The focus would primarily be on making use of uninhabited or underpopulated land.

Regardless, birth rates have been falling around the world, which may slow down population growth in the future. As of 2017, the total fertility rate for the world was 2.5, down from 2.8 in 2002 and 5.0 in 1965, but still at a rate that allows population growth.

Growth Rates Highest in Poorest Countries

According to World Population Prospects: The 2017 Revision, most of the world's population growth is in poor countries. The 47 least developed countries are expected to see their collective population nearly double from 2017's one billion to 1.9 billion by 2050. That's thanks to a fertility rate of 4.3 per woman. Some countries continue to see their populations explode, such as Niger with a 2017 fertility rate of 6.49, Angola at 6.16, and Mali at 6.01.

In contrast, the fertility rate in many developed countries was below replacement value (more loss of people than those born to replace them). As of 2017, the fertility rate in the United States was 1.87. Others include Singapore at 0.83, Macau at 0.95, Lithuania at 1.59, the Czech Republic at 1.45, Japan at 1.41, and Canada at 1.6.

According to the UN Department of Economic and Social Affairs, the world's population has been rising at a rate of roughly 83 million people every year, and the trend is expected to continue, even though fertility rates have been dropping in almost all regions of the world. That's because the world's overall fertility rate still exceeds the rate of zero population growth. The population-neutral fertility rate is estimated at 2.1 births per woman.