Human Population Size
Overview
It took the whole of human history until around 1800 for the world to reach its first billion people. The eighth billion arrived in late 2022, just twelve years after the seventh. Every day the planet gains roughly 200 000 more people than it loses. Understanding why the human population changes so fast, and what that growth does to cities, resources and the environment, is one of the central questions in environmental management.
In this lesson you will learn the four levers that change a population: birth rate, death rate, immigration and emigration. You will calculate natural increase, follow a country through the demographic transition, and weigh the push and pull factors that drive people from the countryside into ever-larger cities. Then you will trace the real consequences of rapid growth, from informal settlements and megacities to pressure on water, energy, land and clean air.
Objectives
- 7.2.1 Describe and explain the factors that affect changes in human populations, limited to: (a) birth rates: children per woman (b) death rates: life expectancy (c) migration: emigration, immigration and push and pull factors (d) rural and urban migration (e) urbanisation.
- 7.2.2 Describe the impacts of human population growth, limited to: (a) informal urban settlements (b) megacities (c) availability of resources (d) energy usage (e) sanitation (f) water supply (g) management of waste (h) availability of land (i) facilities and infrastructure (j) air, land, light, noise, visual and water pollution (k) traffic congestion (l) changes in employment opportunities.
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Lesson Evaluation
Congratulations on completing the lesson on Human Population Size. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.
You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.
Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.
- The rate of natural increase of a population is calculated as: A. Birth rate plus death rate B. Birth rate minus death rate C. Birth rate plus migration D. Death rate minus birth rate Answer: B
- A country has a birth rate of 24 per 1000 and a death rate of 9 per 1000. Its rate of natural increase is: A. 1.5% per year B. 2.4% per year C. 0.9% per year D. 3.3% per year Answer: A
- The movement of people out of an area is called: A. Immigration B. Emigration C. Urbanisation D. Natural increase Answer: B
- Which of the following is a pull factor that attracts people to cities? A. Drought and famine B. Poverty C. Better-paid jobs D. Poor services Answer: C
- In which stage of the demographic transition model is the death rate falling rapidly while the birth rate stays high? A. Stage 1 B. Stage 2 C. Stage 4 D. Stage 5 Answer: B
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