Acid rain is precipitation with a pH lower than normal. The lower pH and increased acidity is due to air pollution caused primarily by the burning of fossil fuels.

Acid rain [local] contains higher than average levels of sulfuric or nitric acids (pH below 5.5-5.6). These acids are produced when sulfur dioxide and various nitrogen oxides combine with atmospheric moisture.

The United States and Canada are the most susceptible [local] to acid rain due to the high use of automobiles. Acid rain can have detrimental effects [local] on the environment and certain physical structures. However, acid rain is best known for its harmful effects on lakes and aquatic ecosystems [local].

The U.S. has been battling acid rain for over a decade, and they claim that their program is working. Canada claims that most of the acid rain that falls on their country comes from the United States, and they need to do more to combat the problem. Is the acid rain problem being addressed effectively? [local]