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Engineering LibreTexts

3.1: The Human Population

  • Page ID
    12172
  • learning objectives

    By the end of this chapter, you will be able to:

    • State the current size of the human population.

    • Interpret age-structure diagrams.

    • Explain what the demographic transition model represents and describe the societal changes that cause the demographic transition.

    • Describe what happens to birth rates, death rates, population growth rate, and population size as a country moves through the stages of the demographic transition model.

    • Give examples of countries in the different stages of the demographic transition models and match age-structure diagrams with the stages of the demographic transition model.

    • Define life expectancy and explain how it changes as a country moves through the demographic transition model.

    • Define fertility and explain how it changes as a country moves through the demographic transition model.

    The human population is growing rapidly. For most of human history, there were fewer than 1 billion people on the planet. During the time of the agricultural revolution, 10,000 B.C., there were only 5-10 million people on Earth - which is basically the population of New York City today. In 1800, when the Industrial Revolution began, there were approximately 1 billion people on Earth (Figure \(\PageIndex{1}\)). We’ve added 6 billion people to the human population in just a little over 200 years. This demonstrates the capacity of the human population to exhibit exponential growth (Chapter 2). What is the current human population? Use this World population clock link to determine the current human population: http://math.berkeley.edu/~galen/popclk.html

    Screenshot (26).png

    Figure \(\PageIndex{1}\): Shows the increase in human population size starting in 1750 and predicted out to 2050. The orange area represents the human population in industrialized countries and the blue/green area represents the human population in less-industrialized (developing) countries. The greatest amount of human population growth will be in less-industrialized countries.