Bavaria, Germany, high-altitude forest damaged by acid rain. Photo by Spitzbergler. From AccuWeather.
Wisconsin passed one of the first and strongest state acid rain control laws in the nation in 1986, making the state a leader in acid rain policy; Clean Wisconsin had an active role in getting that law passed.
Acid rain results from sulfur dioxide and nitrogen oxides entering the atmosphere. These two pollutants are mainly produced by human activities; sulfur dioxide is a common emission from coal-fired power plants and factories, while nitrogen oxides come from vehicles, engines, coal-fired power plants, factories, even home furnaces.
The Acid Rain Law required Wisconsin’s major electric utility companies to reduce their sulfur dioxide emissions by 50 percent from 1980 emission levels by 1993. It was a great success: By 1990, three years earlier than specified in the law, overall annual sulfur dioxide emissions from Wisconsin electric utility companies had fallen 46 percent, and in 1992, all were in compliance.
The law also sought to raise the pH of Wisconsin’s rain; the pH scale is a measure of a material’s acidity or alkalinity and the lower the number, the more acidic something is on a scale of 0 to 14. Battery acid, for instance, has a relative pH of 1, while milk of magnesia, which helps quell an upset stomach, has a pH factor of 10 to 11. Rain uncontaminated by any pollutants has a pH of 5.0 to 6.0; rain with pH less than 5.0 to be “acid rain.
The higher level of acidity in acid rain makes it a threat to plants, fish and to some manmade materials and structures. Acid rain (or snow or fog or smog) can overwhelm the neutralizing capacity of some soils and lake water, leaving the environment unable to defend itself against the effects of these acids. Look at photos of Germany’s Black Forest and New York’s Adirondack Mountains to see the devastating effects acid rain can have on the natural landscape.
In addition to state law, Congress passed the Clean Air Act Amendments of 1990, which contained strong acid rain control measures. This federal law required electric utility companies nationwide to reduce their collective sulfur dioxide emissions by 10 million tons per year (which is a 40-percent reduction) from 1980 emission levels by the year 2000, as well as a reduction in nitrogen oxide emissions of about two million tons per year.
Moving to cleaner, renewable energy sources and increasing energy-efficiency measures would have massive impacts on acid rain in Wisconsin, and Clean Wisconsin continues to work for these policies in the state. You can play a role as well. In addition to supporting our work, reduce your energy consumption with easy actions such as switching to CFLs, turning back your thermostat and purchasing energy-efficient appliances when you need to upgrade to reduce your reliance of coal-powered energy.
The new year brings changes to some of our largest polluters. Power plants, refineries and other large industrial sources will be required to obtain permits for greenhouse gas emissions, just as they do for other pollutants.