Acid rain refers to rain water that is slightly acidic due to the presence of air pollutants like sulfur dioxide and nitrogen oxides, much of which come from power plants and auto emissions. Acid rain impacts lakes and streams, trees and forests, and the decay of building materials and paints. The pollutants that cause acid rain also contribute to smog, haze, and health issues.

This Reading provides background information on the underlying concepts in the Activities included in the Project Earth Science: Meteorology, Revised 2nd Edition. The Reading goes beyond what is found in the background information in the activities. The Reading can be used as supplementary information for the teacher, or to enhance classroom discussions.