Note that the various gases are important. Nitrogen supplies the nitrogen needed by plants by lightning converting nitrogen into forms that the plants can use. Also without the presence of nitrogen, there will spontaneous combustion of earth materials. Oxygen is used by humans and animals. Water vapor is important as it provides rain, snow sleet, hail and helps to insulate the earth from the sun's rays.
Carbon dioxide is a greenhouse gas.
Stress the input by us. Ozone occurs naturally in the stratosphere and helps to protect us from harmful ultra violet radiation from the sun. Depletion of the ozone layer can lead to increase in skin cancer, reduction in crop yield, and killing of certain aquatic life form. Hydrosphere Let us examine the ocean. The oceans are very important in terms of function.