Acid Rain

Pollution from the burning of fossil fuels, as used to generate electricity and power automobiles, has led to a problem with acid rain. In short, chemicals such as nitrogen oxides, sulfur compounds, and hydrocarbons combine in the atmosphere with water to form nitric and sulfuric acids, which subsequently fall to the Earth when it rains. This leads to a number of problems ranging from the destruction of historic sandstone sculptures in cities to the killing of forests. Although this problem has been recognized, its solution is not as straightforward as with the ozone layer, as at present there are not any commercially viable alternatives to burning fossil fuels that are available on a large scale.