What Exactly Is Acid Rain?
Acid rain encompasses more than what we normally think of as rain; it also includes acidic clouds and snow, as well as other ways that acid is deposited from the atmosphere to the earth. Acid rain results from the burning of fossil fuels such as coal and oil. Smoke stacks and tail pipes emit sulfur dioxide and nitrous oxides into the atmosphere, where they mix with atmospheric moisture to form sulfuric and nitric acids. This pollution can be transported hundreds of miles on air currents and return to the Earth’s surface as acid rain. At Lakes of the Clouds Hut, AMC studies began in 1984. At an elevation of about 5,000 feet, clouds are a near-constant presence at this site. The AMC’s research here bears out the importance of cloud vapor — which envelops the environment and condenses to water when it comes in contact with plant surfaces — as a source of acid pollution. Acidity is measured using the pH scale, which runs from 0 to 14. A pH value of 7 is considered neutral, while numbers be
