Of the one-third of the earth's surface covered with land, only a portion is useable for farming and living. Deserts are too hot and mountain regions are usually too rocky and rough. Snow covered areas are too cold and extreme to support farming. Life is supported by the plants which live in the soil. Many other organisms and bacteria are also active and living in the land.
Air surrounds the earth like a large envelope.
People, plants, and animals need the clean air to live and survive. The air that surrounds our planet is affected by all the activities that take place on the earth. Once this air is fouled, there is no way for humans to replace it. The atmosphere protects us from harmful rays and heat of the sun. Water is another renewable resource.