Causes of Acid Rain

Even before we start discussing the causes of acid rain, you need to understand that acid rain doesn't mean acid falling from the sky. It may seem very childish to start the write-up with such a statement, but this very ignorance about some important acid rain facts, including what is acid rain and what are its effects, has resulted in large-scale circulation of misconceptions about it. Basically, acid rain refers to precipitation wherein the water coming to the surface of the planet is highly acidic, i.e. low in pH value, in nature. Use of terms like pH value and acidic may make it seem like the process is very intricate, however, that is not at all the case. Understanding what causes acid rain can explain how the pH content of rainwater is lowered to an extent that it can turn out to be harmful for all lifeforms on the planet.

What are the Causes of Acid Rain?

If we are supposed to answer that question in one sentence the answer would be - all anthropogenic activities which result in air pollution. That, however, doesn't quite highlight the seriousness of this environmental issue. In fact, one has to delve deeper into various acid rain causes in order to understand how we are contributing to this hazard and what the future implications of acid rain are. The entire process starts with us releasing hazardous chemicals such as sulfur oxide and nitrous oxide in the atmosphere as a result of burning of fossil fuels. These chemicals, which have the ability of dissolving in water with immense ease, are suspended in the atmosphere in form of microscopic particles. When it starts raining, these particles get dissolved in the water and come down to the Earth. However, when they dissolve in rainwater they alter its chemical content and make it more toxic.

That, however, doesn't mean only air pollution is responsible for acid rain as even water pollution has the tendency to do so. When polluted water is evaporated as a part of the water cycle, all the pollutants in it get evaporated with water. When this contaminated water comes down, the pollutants in it react with chemical substances present in the atmosphere and cause acid rain. That explains one of the lesser known facts about acid rain which states that oils spills play a key role in this phenomenon.

Causes of Acid Rain: Chemistry Perspective

A look at the chemistry of acid rain gives you a brief overview as to what actually happens during the occurrence of this phenomenon. In course of precipitation various particles that are suspended in the atmosphere of the Earth get dissolved in water and come down to the surface of the Earth. These particles include dust, carbon dioxide, volcanic ash, etc. As a result of this, the pH value of rainwater decreases and this water becomes acidic in nature. (Basically, water with its pH value less than 7 is considered to be acidic water). While dust, carbon dioxide, volcanic ash, etc. can be regarded as the natural causes of acid rain, the implications caused as a result of the entire phenomenon don't become severe until certain harmful chemical substances - including sulfur, phosphoric acid, hydrochloric acid, etc. don't come into play. As we mentioned earlier, these chemical substances are released in the Earth's atmosphere as a result of various human activities. When these chemicals get dissolved in rainwater, they further bring down its pH levels to as low as 3.5 - thus making it more acidic and harmful for various lifeforms on the planet.

These causes and effects of acid rain are quite severe, and therefore we need to look into the matter seriously. The need of the hour is to identify various acid rain solutions, and implement them at the earliest. Any further delay will only increase the intensity of the numerous acid rain effects on plants and animals on this planet, and eventually make it a barren planet - incapable of supporting life.