Gaia, the Grand Idea

This introductory chapter discusses the Gaia hypothesis as well as two other competing hypotheses. Gaia, the idea that life moderates the global environment to make it more favorable for life, was first introduced in 1972 in an academic paper by James Lovelock titled “Gaia as Seen through the Atmosphere.” The Gaia hypothesis proposes planetary regulation by and for the biota, where the “biota” is the collection of all life. Lovelock suggests that life has had a hand on the tiller of environmental control, and the intervention of life in the regulation of the planet has been such as to promote stability and keep conditions comfortable. The chapter then looks at the geological hypothesis, which suggests that the nature of the Earth's environment is principally determined by a mixture of geological forces and astronomical processes, and the coevolutionary hypothesis, which asserts that life has had an enormous impact on the planetary environment.