Acid rain: two words that are not very pretty. Instead of the romantic rain that most of us would like to imagine, acid rain brings to mind frightening images of a future wrought with pollution and other problems. But what is acid rain and what is it caused by? And is acid rain really a by-product of global warming? The short answer is both yes and no. Acid rain has causes that are rooted both in nature and in the human activity that is causing the effects of global warming to become more pronounced.
In scientific terms, acid rain refers to any kind of precipitation, including mist, snow, fog, and of course, rain, that is more acidic than normal. Most rain is naturally a bit acidic, but acid rain contains an above average level of acid in it. Generally speaking, acid rain is caused by emissions of sulfur dioxide and nitrogen oxides that react with hydroxyl radicals and water vapor that exist in many industrial environments. When this combination exists, the acid rain may come down as either dry acid deposition or, when it is mixed with water, it is known as acid rain.
What is most acid rain composed of? Acid rain as it falls in the eastern part of North America and parts of Europe is composed mostly of sulfuric acid and nitric acid. How do these things make up acid rain? Acid rain generally occurs when the burning of fuels produces sulfur dioxide and nitrogen oxides. These different oxides get into our atmosphere because of both natural environmental activity as well as human activity. When these oxides reach the troposphere, they become oxidized by the hydroxyl radicals in the atmosphere that then break down the oxides into sulfuric and nitric acids. These acids will usually break down readily into water that is then brought down in the form of precipitation, or acid rain.
So is acid rain a by-product of global warming? It is not so simple. Many natural sources are also a part of acid rain. Many tons of sulfur is released into the earth's atmosphere each year from natural sources, including volcano eruptions, microbial processes, and sea sprays. Nitrogen oxides are also released into the earth's atmosphere in a natural manner, including from burning, lightning, the burning of biomass, and many microbial processes.
However, in a sense, acid rain is indeed a type of by-product of global warming because human activity often is responsible for some kinds of acid rain. It is estimated that human beings release up to 100 to 130 million tons of sulfur dioxide into the atmosphere. Human beings are also estimated to be responsible for roughly 60 to 70 million tons of the nitrogen oxides that are released into the earth's atmosphere each year. Most acid rain occurs in highly industrialized areas where these oxides are released into the earth's atmosphere on a regular basis. However, human activity has caused more oxides to be released into the earth's atmosphere in certain concentrated areas. Thus, human activity is definitely a strong factor in the occurrence of acid rain, especially in highly concentrated areas.
The effects of acid rain are becoming recognized as a growing problem, especially around highly industrial areas. Areas that have been highly industrialized for more than 100 years are considerably more susceptible to experiencing acid rain. However, all parts of the world are susceptible to some kind of acid rain. Acid rain is especially having an effect on many fragile ecosystems, including many of the earth's aquatic ecosystems. Acid rain can also have a devastating effect on forests.