Acid rain is caused by emissions of sulfur dioxide and nitrogen oxides from burning fossil fuels like coal and oil. These gases mix with water vapor and fall to earth as rain with a pH lower than normal. Acid rain damages trees, forests, lakes, and buildings by dissolving stone and corroding materials. It also harms fish populations and can cause respiratory issues and other health problems for humans. Solutions include reducing emissions at power plants, conserving energy to burn less fossil fuels, developing renewable energy sources, and installing catalytic converters on vehicles.