Table of Contents Just People 4 People and the Air 10 People and the Water and Land 17 People and Renewable Energy 24 People Pollution and the Planet 30 Animal Habitats and the Planet 36 Balancing the Planet 41 Glossary 46 Index 47 Show What You Know 47 Websites to Visit 47 About the Author 48
Just People The population of the world we live in grows every eight seconds Earth has more than 7 2 billion people living on it The United States is the third most populated country in the world behind China and India Population affects the planet in many ways Much of the world’s air water and land are facing a global crisis China is the most densely populated country with nearly 1 4 billion people China 4
The challenge is to create and maintain an effective sustainable way of living that involves preventing global warming and climate change clean air and water the management of natural and manmade resources to avoid waste and protecting energy supplies and all living things Many branches of science involve people and the planet Broadly they all fall under the category of natural science 5
