The environment is something you are very familiar with. It’s everything that makes up our surroundings and affects our ability to live on the earth—the air we breathe, the water that covers most of the earth’s surface, the plants and animals around us, and much more. In recent years, scientists have been carefully examining the ways that people affect the environment. They have found that we are causing air pollution, deforestation, acid rain, and other problems that are dangerous both to the earth and to ourselves. These days, when you hear people talk about “the environment”, they are often referring to the overall condition of our planet, or how healthy it is.