Acid Rain Learning Center

Along with the wonderful conveniences that the Industrial Revolution has brought to modern society is the unfortunate side effect of air pollution. Many of the products that are taken for granted today are made in factories that produce chemical emissions in the manufacturing process. Even the production of electricity itself in many parts of the world creates pollutants through the burning of coal and other fossil fuels. In addition to fouling the air and harming the lungs of many people, much of this pollution combines with water in the atmosphere and falls to the earth in the form of acid rain.

Technically speaking, acid rain can refer to any kind of acidic precipitation, though this article focuses on rain itself. In ordinary circumstances, almost all rain is acidic to some degree because of the presence of nitrogen and carbon dioxide in the earth’s atmosphere. Molecules of these substances react with water vapor as droplets are formed, making the precipitation acidic. Nitrogen and carbon dioxide are naturally present in the ecosystem, and come from a variety of sources such as plant respiration, volcanic eruptions, and the decay of vegetation. The burning of fossil fuels, however, releases more of these substances into the atmosphere, increasing the presence of these chemicals and contributing to an increase in the acidity level of rainfall. Rain that is more acidic than normal is termed “acid rain.”

Rain with an acidity level that is above normal is greatly harmful to the environment. It can cause nutrients to leach from soils, making it impossible for native vegetation to thrive in areas where much acid rain has fallen. Acid rain also makes plants more susceptible to pest infestations and diseases because it causes plants’ natural defensive systems to grow weak and ineffective. As the rain falls into lakes and runs off into streams, many fish species are also killed. Additionally, human health can be greatly impaired, and buildings and cars can also suffer corrosion. In sum, acid rain is not really good for anyone or anything.

Recognizing the problems that acid rain creates, many governments have taken steps to reduce and even eliminate acid rain. In the United States, the Clean Air Act of 1963 is the most important piece of legislation written to confront the problem of acid rain and reduce atmospheric pollutants. This piece of legislation has been amended several times since it was first passed, and the amendments offered in 1990 rank among the most important for taking care of the underlying causes of acid rain. Additionally, there are international efforts underway to facilitate global cooperation in reducing air pollution all across the planet.

In the future, it is possible that even more drastic steps will have to be taken to reduce air pollution. Today, individuals can do simple things to reduce their dependence on fossil fuels, leading to a collective reduction in the amount of theses substances to produce electricity and other things. Carpooling, walking or riding a bike, recycling, and other such efforts can go a long way towards helping to solve the problem of acid rain.

For more information on acid rain, please consult the following:

What is Acid Rain?

• Acid Precipitation — Acid precipitation is a more accurate name for acid rain because acid can fall to the earth apart from rain drops, as this site reveals.

• All About Acid Rain — An environmental systems engineering student developed this overview page on acid rain, its causes, treatments, and more.

• Natural "Acid" Rain — This page has good chemical information on normal rain and how it differs from acid rain.

• Our Changing Planet — A PBS series on acid rain is behind this overview site all about acid rain.

• TAMU: Acid Rain — Here is a good overview page on acid rain that includes information on its origin and what can be done about it.

• USGS: Do You Need to Start Wearing a Rain hat? — The U.S. Geological Survey is the home of this informative overview page on acid rain.

What Causes Acid Rain?

• Acid Rain — Causes — Discover the causes of acid rain with this brief and informative resource.

• How Does Acid Rain Form? — Brief information on the formation of acid rain is found on this page.

• Our Land, Our Literature — The information on air pollution, the primary cause of acid rain, found on this site about Indiana is applicable to industrial areas across the United States.

• What is Acid Rain and What Causes It? — Besides giving information on the origin of acid rain, this page also includes information on what can be done to combat it.

• What Causes Acid Rain? — A great kids page on the causes of acid rain from the U.S. Environmental Protection Agency can be accessed via this link.

How Do We Measure Acid Rain?

• Analysis Method — This page from a University of Massachusetts site that measures acid rain in that state describes an analysis method that can be used to measure the acidity of rain anywhere.

• Measuring Acid Rain — This site has some brief information on the pH scale, which is used to measure the acidity of rain.

• National Atmospheric Deposition Program — The National Atmospheric Deposition Program measures acid rain in different parts of the United States.

• Why is pH Important? — This page has more extensive information on the pH scale used to measure acid rain.

What Are the Effects of Acid Rain?

• Acid Deposition Case Studies — Some information on acid rain around the world is featured on this website.

• Acid Rain and Acid Deposition — Scroll down a little on this informative page to read about the effects of acid rain on seawater, soil, and more.

• Effects of Acid Rain — After some brief information on the chemical composition of acid rain, this site details its effects on many different plants and animals.

• Effects of Acid Rain: Lakes and Streams — The Environmental Protection Agency from the United States provides this page with information on the effect of acid rain on lakes and streams.

• The Effect of Acid Rain on Plants — This page details a group lab project that measured the effect of acid rain on plants, including pictures of the experiment and information on its results.

• Wood Thrush Declines Linked to Acid Rain — This article details the effect of acid rain on the North American bird known as the Wood Thrush.

What is Being Done about Acid Rain?

• Acid Rain Fact Sheet — Scroll down to find some good information on reducing acid rain and solving the problem of pollution.

• The Acid Rain Retirement Fund — The Acid Rain Retirement Fund is an organization that is dedicated to eliminating acid-rain-causing pollutants through the purchasing of pollution allowances.

• A Changing Climate of Opinion — The Economist reports on theories from several individuals on how to address climate problems, including acid rain.

• The Clean Air Act — The Clean Air Act is perhaps the most important U.S. law that addresses the underlying causes of acid rain.

• Strange Air-Cleaning Molecule — This news article describes the recent discovery of a natural molecule in the atmosphere that helps lower the acidity of rain.

 Acid Rain Educational Resources

• Acid Rain and How It Affects Our Environment — Teachers should find this lesson plan and experiment suggestion helpful for instructing kids about acid rain.

• Acid Rain Simulation — Science lab teachers can find an experiment that simulates acid rain for their students on this page.

• Acid Rain Web Quest — Instructors may find this web quest useful for teaching students all about acid rain.

• Chemistry of Acid Rain — Here is an acid rain worksheet and lesson plan that helps students learn the causes of acid rain and important details about it including pH levels and more.

• The pH Factor — The pH Factor is an extensive teacher’s guide and plan for educating students about acidity levels in rain.

• The Production of Acid Rain — This is another experiment that teachers can do with their students to simulate the production of acid rain.