Cutting down trees and not replacing them. It hurts the air quality because it reduces the number of trees that produce oxygen for us to breathe. Trees also help delay the greenhouse effect because they use carbon dioxide, which helps maintain air quality. In addition, trees protect the soil and hold it in place. An item that is made to be used once and then thrown away.
Disposable items create unnecessary garbage.
Animals that may become extinct. Any animal overhunted by people or whose food needs are not met will not survive. Each day three species on earth become extinct, a rate 400 times greater than that 1,000 years ago. Though there are laws to protect endangered animals, it is often too late to save more than a few of the species. Major hazardous wastes include medicinal wastes, sewage, and pollution from factories.