Germany faces significant environmental issues from air pollution and acid rain. Major sources of air pollution in Germany are coal-burning factories and vehicle emissions in large cities. This pollution contributes to acid rain when sulfur and nitrogen oxides react in the atmosphere to form acids. Acid rain has severely damaged forests, especially the Black Forest, harming Germany's timber economy. While Western European countries have enacted policies to reduce pollution, Germany and other Eastern European countries need to further develop renewable energy and implement more stringent environmental protection policies.