The continent of Africa has the highest fertility rates in the world, with countries such as Nigeria-Africa’s most populous and the world’s eighth most populous country-growing rapidly each year. World population increase is pronounced on the continent of Asia: China and India are the most populous countries in the world, each with more than a billion people, and Pakistan is an emerging population giant with a high rate of population growth. In 2010, the world’s population was growing by about eighty million per year, a growth rate found almost exclusively in developing countries, as populations are stable or in decline in places such as Europe and North America. Although the exact figures are unknown, demographers expect the world’s population to stabilize by 2100 and then decline somewhat. This means that population growth rates-while still higher in the developing world than in the developed world-are declining. Meanwhile, birth rates-and family size-have also been declining in most developing countries as people leave agricultural professions and move to urban areas. Low death rates and high birth rates resulted in rapid population growth. In developing countries with agricultural societies, however, birth rates remained high. During the twentieth century, death rates due to disease and malnutrition decreased in nearly every corner of the globe. This rapid growth occurred as the demographic transition spread from developed countries to the rest of the world. One hundred years later, there were roughly six billion people in the world, and as of 2011, the number was approaching seven billion. The process just described is called the demographic transition.Īt the beginning of the twentieth century, the world’s population was about 1.6 billion. In some countries (e.g., Russia and Japan), population is actually in decline, and the average age in developed countries has been rising for decades. Fewer families worked in agriculture, more families lived in urban areas, and women delayed the age of marriage to pursue education, resulting in a decline in family size and a slowing of population growth.
However, by the middle of the twentieth century, birth rates in developed countries declined, as children had become an economic liability rather than an economic asset to families. Things changed dramatically during Europe’s Industrial Revolution in the late 1700s and into the 1800s, when declining death rates due to improved nutrition and sanitation allowed more people to survive to adulthood and reproduce.
Only about five hundred million people lived on the entire planet in 1650 (that’s less than half India’s population in 2000). Geographers study how populations grow and migrate, how people are distributed around the world, and how these distributions change over time.įor most of human history, relatively few people lived on Earth, and world population grew slowly. It is a branch of human geography related to population geography, which is the examination of the spatial distribution of human populations. Demography is the study of how human populations change over time and space.
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