Part Two, Issue 1

Global Population Growth

Objectives

After reading the assigned chapter and reviewing the materials presented the students will be able to understand:•What is the Earth’s population and how fast it is growing•How does human population growth threaten the environment?•Is human population growth sustainable?

Introduction

• First we take up space that at one time was forest, wetland, prairie, or hillside.

• In addition, we require land for agriculture.• The waste created by our increasing human

numbers is another major environmental problem.

Exponential Growth and Its Impacts

• The earth’s human population was about 6.52 billion in mid 2006 and growing at 1.14 percent per year.

• The compound growth equation allows demographers to project future population size (N), based on current population (N0), and the population growth rate (r): Future value N = Present value N0 x (e) r t .

• Population estimates are compiled from censuses all over the world.• For any population growing exponentially, the time (t) it takes for the

population to double is calculated using: t = 70 / r where r is the decimal growth rate. Seven percent growth rate is entered as .07

• Developing countries are experiencing the most rapid population growth.

Impact of AIDS

• According to the United Nations, AIDS is having a devastating effect on countries in Africa.

• In Botswana, one of every four adults is infected with HIV, the virus that causes AIDS.

Summary• First we take up space that at one time was forest, wetland, prairie, or

hillside.• In addition, we require land for agriculture.• The waste created by our increasing human numbers is another major

environmental problem.• Population estimates are compiled from censuses all over the world.• For any population growing exponentially, the time (t) it takes for the

population to double is calculated using: t = 70 / r where r is the decimal growth rate.

• Developing countries are experiencing the most rapid population growth.• According to the United Nations, AIDS is having a devastating effect on

countries in Africa.

Home Work

• 1. How are population estimates compiled?• 2. Which countries are experiencing the most

rapid population growth?