Acid rain is a pollution problem because it transcends political boundaries. After much research and understanding of the acid rain problem in the 70s and 80s, Canada and the United States did not have a joint agreement in emission controls. However, the US held off making any policies until late 1990 after amendments to the Clean Air Act . Atmospheric pollution can be transported large distances by air masses and then precipitated somewhere else. It was ironic for industrial plants to build extremely tall smokestacks because it made local pollution problems become a regional one.
Acid rain is still a very large environmental problem that the world is trying to solve.
Until the atmospheric release of pollutants is stopped, acid rain will continue to fall and become one of the greatest examples of the destructive behaviour of mankind.