title: How life affects the atmosphere.
abstract: The impact of life on the atmosphere is examined through a discussion of the budgets of important atmospheric constituents and the processes that control their concentrations.  Life profoundly influences oxygen and a number of minor atmospheric constituents, but many important gases, including those with the greatest effect on global climate, appear to be little altered by biological processes, at least in the steady state.
authors.affiliation: Department of Atmospheric and Oceanic Science, University of Michigan, Ann Arbor 48109, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Walker
mesh_terms: D001272:Atmosphere / Q000032:analysis / Q000737:chemistry*; D002245:Carbon Dioxide / Q000032:analysis / Q000378:metabolism; D002980:Climate; D005740:Gases / Q000032:analysis*; D019369:Life; D009584:Nitrogen; D005741:Noble Gases; D010100:Oxygen / Q000032:analysis / Q000378:metabolism*; D010126:Ozone; D010788:Photosynthesis
chemical_list: D005740:Gases; D005741:Noble Gases; D002245:Carbon Dioxide; D010126:Ozone; D009584:Nitrogen; D010100:Oxygen