The environmental challenges we face -- Environmental sustainability and human values -- Environmental history, politics, and economics -- Risk analysis and environmental health hazards -- Hoe ecosystems work -- Ecosystems and evolution -- Human population change and the environment -- Air and air pollution -- Global atmospherics changes -- Freshwater resources and water pollution -- The ocean and fisheries -- Mineral and soil resources -- Land resources -- Agriculture and food resources -- Biological resources -- Solid and hazardous waste -- Nonrenewable energy resources -- Renewable energy resources.