Sometimes its hard to see the big picture. Its difficult to step outside ourselves and realise that we are part of something larger than ourselves. Our plant is a living system and we are an organism on its skin – one that is rather parasitic at the moment though we could be benign.
To get a view of the living planet see the following report from the Earth Observatory. The sequence of photos linked shows the planet breathing.
Life is an integral part of the Earth system. Living things influence the composition of the atmosphere by “inhaling” and “exhaling” carbon dioxide and oxygen. They play a part in the water cycle by pulling water from the soil and the air, and they help put it back again by exhaling water vapor and aerating the soil so rain can soak into the ground. They regulate ocean chemistry by taking carbon out of the atmosphere. Earth would not be the planet that it is without its biosphere, the sum of its life.