When we discuss the Earth's environment, we are talking about the
health of the atmosphere, forests, plants, animals, water, and each
ecosystem. Everything from the roots of trees underground to the air we
breathe is part of the environment, and the health of each part affects
the health of the whole. There are a lot of threats to the environment.
These include: climate change caused by greenhouse gasses, air and water
pollution, deforestation, and more. As a result of so many serious
environmental threats, the Earth is changing. Melting glaciers are
destroying habitat in the Arctic; plants and animals are becoming
extinct at a staggering rate. It's easy to look at that list and feel
small and insignificant. After all, the Earth has over 7 billion people.