18.0 Ecosystems and Human Populations

A sea of people throngs the street of La Plaine Saint-Denis, France. How many people do you see? Are there too many to count? This photo shows just a tiny fraction of the billions of people who live on Earth today. Our vast numbers show that we are a very successful species. But our numbers are also a problem. We are harming the environment. We are affecting ecosystems all over the planet.

How did the human population become so large? How are we affecting Earth’s ecosystems? In this chapter, you’ll find out.