This document discusses several types of pollution including acid rain, the greenhouse effect, global warming, and water pollution. It provides explanations of what causes each type of pollution, such as factories and power plants emitting gases that cause acid rain when it rains. Solutions proposed include reducing emissions and fossil fuel use. The greenhouse effect and global warming are discussed as being caused by increased carbon dioxide and methane trapping heat in the atmosphere. The Kyoto Protocol aimed to reduce gas emissions but the US did not adopt it. Water pollution comes from waste waters from human activities that contaminate rivers and oceans.