How have humans polluted the planet? -- What causes air pollution? -- How is air pollution related to climate change? -- What other problems does air pollution cause? -- How can land pollution affect lakes and streams? -- Are the oceans polluted? -- What do we do with fresh water? -- How can pollution affect animals and plants? -- What are we doing about pollution? -- What more can we do to reduce pollution? -- Can we clean up polluted areas? -- Can we protect wild habitats from pollution? -- How can we protect individual species?.