Skip to main content

What Is Acid Rain? Causes and Effects of Acid Rain

Muhammad Rafiq is a freelance writer, blogger, and translator with a master's degree in English literature from the University of Malakand.

Read on to learn all about acid rain, including what it is, what causes it, and how it effects our world.

Read on to learn all about acid rain, including what it is, what causes it, and how it effects our world.

What Is Acid Rain?

Acid rain is a type of precipitation that is unusually acidic, meaning that it has a pH level generally below 4.4, or it is a ‘rain’ that becomes acidic due to atmospheric-acidic emissions. These emissions can be from coal-fired power plants (to produce electricity, for example), factories, cars, other large machines, etc.

The emissions, in this case, are sulfur dioxide and nitrogen oxides. The sulfur dioxide and nitrogen oxides that escape into the air are oxides of sulfur and nitrogen and combine with water in the air to form acid rain. Acid rain is formed when particulates (sulfur dioxide and nitrogen oxides) react with the water vapor in the air. When these particulates are in the atmosphere, they form into droplets of acid rain. When the droplets fall to the ground, they either evaporate or turn to rain again when they hit the ground.

The deleterious effects of acid rain are far-reaching and can be seen in both natural and man-made environments. In forests, acid rain can cause the death of trees and other plants, as well as the leaching of nutrients from the soil. This can lead to a decline in the productivity of the ecosystem, affecting both the flora and the fauna. In addition, acid rain can cause corrosion of man-made structures and monuments, such as buildings and statues.

5 Causes of Acid Rain

There are many different causes of acid rain, but the most common ones are explained below:

  1. Coal-Fired Power Plants
  2. Vehicle Emissions
  3. Volcanic Activity
  4. Natural Fires
  5. Decaying Vegetation
A pH scale showing how acidic or basic various substances are in relation to acid rain.

A pH scale showing how acidic or basic various substances are in relation to acid rain.

1. Coal-Fired Power Plants

The first cause of acid rain is coal-fired power plants. When coal is burned in power plants, the sulfur dioxide that is created escapes into the atmosphere, where it is broken down by moisture into sulfuric and sulfuric acid. These acid rain contaminants, such as sulfur dioxide, nitrate, and chloride, are carried through the stratosphere and can affect the weather in other regions.

The sulfur released by coal burning reacts with moisture in the air to form sulfuric acid, which fall to the ground as acid rain. Sulfuric acid is the most dangerous form of acid rain, as its corrosive nature can cause acid burns on exposed skin, damage plant life, and damage buildings.

According to the World Nuclear Association, over 15 billion tons of sulfur dioxide are released into air by burning of fossil fuels each year, most of which comes out of the smokestacks of coal-fired power plants. To put it into perspective, the Martin Lake Power Station in Texas has an annual output of nearly 48,000 tons of sulfur dioxide (SO2), making it one of the biggest carbon polluters in the United States. The power plant is located in the town of Martin Lake, Texas, U.S.A.

India is the largest emitter of sulphur dioxide (SO2) in the world, contributing more than 15 percent of global anthropogenic emissions, according to a new report by Greenpeace released on August 19, 2019.

India’s emissions of sulphur dioxide are the result of both coal power plants and the burning of lignite (brown coal), which releases large amounts of sulphur with the coal it is mined. India’s coal industry is dominated by government-owned and -controlled firms, and the industry’s economic performance is listed as one of the factors hindering India’s fight against climate change.


2. Transportation Sector

Transportation sector is the second major cause of acid rain. It is the fastest-growing source of emissions worldwide and accounts for 17 percent of global greenhouse gas emissions - behind only the power sector.

When automobiles belch out pollutants, the chemical reaction between nitrogen oxides and sulfur oxides (commonly known as NOx and SOx) and water vapor in the air produces deadly acid rain. NOx and SOx are gases that are present in the atmosphere, but automobiles release them in an uncontrolled way, causing acid rain. The NOx and SOx react with the water vapor in the air, forming sulfuric and nitric acid mist. Some of the acid mist is known to drop on the ocean, hence damaging marine flora and fauna.

The United States has some of the highest emissions from road transportation per capita in the world. The average American emitted approximately 4,500 kilograms of CO2 from road transport in 2018, which was slightly more than in neighboring Canada. The United States emits more carbon dioxide from road transportation than any other country.

Currently, cars are the biggest source of emissions in the transportation sector, but cars are evolving and becoming increasingly efficient. It’s important to remember that improving fuel efficiency does not only reduce emissions, it also reduces fuel consumption and leads to increased consumer savings.

The increasing use of electric vehicles and improvements to hybrid and plug-in hybrid vehicles are among the steps being taken to combat climate change.


3. Volcanic Activity

The third major cause of acid rain is volcanic activity. Volcanic eruptions release sulfur dioxide and other gases into the atmosphere, which combine with water droplets to produce sulfuric acid aerosols. The aerosols can be carried by winds over large distances, causing acid rain in areas where it is not usually present.

The amount of sulfur dioxide released from volcanoes varies considerably from year to year and from volcano to volcano. In some years, the amount released by volcanoes is more than enough to contribute to global levels of sulfur dioxide in the atmosphere. Other years, there is not enough sulfur dioxide being released from volcanoes to make a significant contribution at all.

The year 2022 saw 69 confirmed eruptions from 67 different volcanoes. Of these, 17 were new eruptions that started during the year. This activity was widely distributed across the globe, with notable eruptions occurring in Indonesia, Iceland, Japan, Russia, and the United States.

These findings suggest that the eruptions could have released large quantities of gas into the atmosphere, contributing to acid rain. This is a cause for concern, as acid rain can have a damaging effect on the environment.


4. Natural Fires

The fourth major cause of acid rain is natural fires. Burning forests and peatlands are a major source of acid rain-causing pollutants. The pollutants emitted from these fires include sulfur dioxide, nitrogen oxides, volatile organic compounds, and particulate matter.

For example, the Ashfall in 1983 followed by the Bhopal gas tragedy was an ecological disaster that took place in India. It was caused by a major fire accident at a pesticide factory, which released methyl isocyanate into the air. Methyl isocyanate is a toxic gas that is known to be highly carcinogenic. It more than 15000 people, while more than 6000,000 workers were badly affected.

The 2019-2020 bushfire season in Australia, colloquially known as Black Summer, is another example of natural fires. It was one of the most devastating on record. Starting in June 2019 and ending in May 2020, the fires and smoke affected over 80 percent of the country's population.

The release of 400 tons of carbon during the fires had a significant impact on the environment. The pollution caused by the fires was far-reaching and had a negative effect on the quality of the air, water, and soil.

In addition to the human toll, the fires also had a devastating impact on the environment and wildlife. Over 19 million hectares of land were burned, and an estimated three billion animals were killed. The bushfire season also exacerbated the country's already-serious drought problem.


5. Decaying Vegetation

Decaying vegetation is the fifth major cause of acid rain. When leaves and other plant matter decay, they release carbon dioxide and other gases into the atmosphere. These gases combine with water vapor to form acid rain. Although these gases are not directly emitted by decaying vegetation, they are produced in large quantities as a result of the decomposition process.

In addition to being an important source of greenhouse gases, plants also contribute to the formation of acid rain by depositing carbon dioxide into the ground during photosynthesis. Trees, shrubs and other plants absorb carbon dioxide from the atmosphere through their leaves, store it in their tissues and then release it when they die or fall over. The decomposition process releases this stored carbon dioxide back into the atmosphere as a gas or dissolved compound.

Because decaying vegetation is responsible for releasing large amounts of these greenhouse gases into the atmosphere, it can have a significant impact on climate change over time. The amount of carbon dioxide released will affect how much additional heat is trapped in our planet's atmosphere, which in turn affects global temperatures and weather patterns around the world.


Effects of Acid Rain on Humans

The human health effects from acid rain are not as well known as the effects on plants and animals. However, some studies have shown that there is a link between exposure to acid rain and increased rates of certain health conditions.

Some studies have found that people who live in areas with high levels of acid rain have a higher risk for developing lung problems than their peers who do not live in these areas. Other research has also linked exposure to acid rain with an increased risk for chronic respiratory problems including asthma attacks.


Effects of Acid Rain on Vegetation

The most obvious effect of acid rain is on trees and plants. Trees absorb carbon dioxide from the atmosphere before it rains down onto the ground, giving them a boost in growth. This can be seen as acidity levels rise. The tree may be killed or die, depending on how much acidity is present in its surroundings.

If a tree does not die, it will suffer severe damage as a result. The bark will turn brown or black and become flaky, while the leaves will fall off completely or may burn, which can lead to more serious health problems for both humans and animals who eat them.

Vegetation can be damaged by acidic deposition as well, through direct contact with the rain or runoff water, or through leaching into water supplies used by humans and animals.

The effect of acid precipitation on vegetation depends on both pH levels and exposure time. The lower the pH value becomes, the more susceptible a plant species is to damage from acid rain.

Acid rain can cause a number of problems for plants, including leaching of essential nutrients, foliar damage, and root damage. These problems can lead to a decrease in plant growth and productivity, and in some cases, death.


Effects of Acid Rain on Animals

Animals such as birds and fish are also affected by acid rain, but they do not enjoy the same protection that trees do against this pollution. Birds breathe in small amounts of air every time they fly through an area where there is an increase in acidity levels compared with their own environment (which usually means higher than normal). As well as inhaling these pollutants directly into their lungs when flying through an area with higher than normal levels of acidity, they may ingest some of this pollution when they eat food that has been contaminated by acid rain.

Scientists have now determined that acid rain has a negative impact on the breeding habits of at least one North American songbird species. This is a significant finding, as it suggests that acid rain may be having a negative impact on the breeding patterns of other songbird species as well.

Acid rain can have devastating effects on fish populations. In addition to birds, fish are especially vulnerable to the harmful effects of acid rain. Acid rain can lower the pH of water bodies, making them more acidic. This can cause fish to experience a number of problems, including reduced growth, reduced reproduction, and increased mortality. In some cases, acid rain can even lead to the complete extinction of fish species.


Effects of Acid Rain on Buildings

Acid rain can have devastating effects on buildings and other structures. The acidity of the rainwater can eat away at building materials, causing them to weaken and crumble. This can lead to serious damage to the structure of a building, and in some cases, the collapse of the building. Acid rain can also cause paint to peel and metal to rust.

Acid rain damages buildings and structures by dissolving stone or corroding metal that is exposed to the weather. The damage is most severe on buildings and statues that contain calcium carbonate or calcium-based compounds.

Old statues, monuments, and tombstones are particularly vulnerable to acid rain because they are often made of limestone. Over time, exposure to acid rain can slowly erode the details of a statue, turning it into a featureless blob. This process, known as weathering, can irreparably damage historical structures and artwork.

In addition to eroding stone, acid rain can also discolor paint, causing it to fade or peel. If left unchecked, acid rain can eventually destroy entire buildings and monuments.


How to Measure Acid Rain?

There are two methods regularly used to measure acid rain. To measure the acidity of rain, pH paper can be used as a qualitative indicator. pH paper changes color based on the acidity of the solution it is placed in, with a range from 0-14. A pH below 7 is considered acidic, while a pH above 7 is considered basic. Moreover, a pH of 7 is considered neutral.

To use pH paper to measure acid rain, simply place the pH paper in the rainwater and compare the color to the pH scale. If the pH paper turns a color that corresponds to a pH below 7, then the rainwater is acidic.

Another method for measuring acid rain is to use a pH meter. This device measures the acidity or alkalinity of a solution and displays the results on a scale of 0 to 14.

pH meters are widely used in many different industries, including in environmental science to measure the acidity of rainwater. This method is considered to be more accurate than other methods, such as the use of litmus paper.

When it rains, the pH of the water is typically around 5.6. This is due to carbon dioxide from the air dissolving into the rainwater and forming weak carbonic acid. However, when acid rain falls, the pH of the rainwater is usually between 4.2 and 4.4.


How to Reduce Acid Rain?

There are a number of things that people can do to help reduce acid rain and its impact.

  1. We can help reduce acid rain by conserving energy. This can be done by using energy-efficient appliances, using public transportation, carpooling, and walking or biking when possible. Conserving energy will help reduce the amount of emissions that contribute to acid rain.
  2. We can help reduce acid rain by planting trees and shrubs. This will help to create a natural barrier that will help to intercept the acid rain before it hits the ground. This is a great way to reduce the amount of damage that acid rain can cause to the environment.
  3. We should support industries and businesses that are working to reduce their emissions. This can include buying products from companies that have green initiatives or investing in companies that are working to develop new, cleaner technologies.
  4. Ammonia emissions from agriculture are a significant source of air pollution. Ammonia is a gas that forms when nitrogen-containing compounds break down. It is also a key ingredient in many fertilizers. When ammonia is released into the air, it can eventually fall back to the ground, where it can contaminate water and soil. Ammonia emissions can also contribute to the formation of fine particulate matter, which can lead to respiratory problems. There are a number of agricultural practices that can reduce ammonia emissions. For example, farmers can choose fertilizers that are less likely to release ammonia into the air. They can also implement management practices that reduce the amount of manure that is produced on their farms. Additionally, farmers can take steps to prevent ammonia-rich manure from coming into contact with the air, such as using covered storage facilities. By taking these measures, farmers can help to reduce the amount of ammonia that is released into the environment.
  5. Catalytic converters can be used on vehicles to reduce the emissions of nitrogen oxides. Nitrogen oxides are a major contributor to air pollution, and they can also have harmful effects on human health. By using catalytic converters, we can help to reduce the amount of these harmful emissions and make the air cleaner for everyone.
  6. We can help spread awareness about the dangers of acid rain by talking to their friends and family about the issue, sharing articles and information about acid rain on social media, and contacting their local representatives to voice their concerns about the issue.
  7. We should support businesses and organizations that are working to mitigate the effects of acid rain, such as by donating to their cause or purchasing their products.
  8. Finally, individuals can help to prevent acid rain by reducing their own emissions of pollutants that contribute to the problem.

By taking these steps, we can help to reduce the negative impact of acid rain and protect our environment.

Questions About Acid Rain

Below you'll find answers to some of the most common questions about acid rain.

Can Acid Rain Cause Death?

Acid rain is a serious environmental problem that can cause a range of negative health effects in humans. In some cases, acid rain can be deadly. A 1984 Congressional report found that acid rain was responsible for the premature death of an estimated 50,000 people in the United States and Canada.

Can Acid Rain Burn Your Skin?

This is a question that we get asked a lot, and it's understandable why. After all, acid is a corrosive substance, so it stands to reason that it could potentially cause burns if it comes into contact with your skin.

However, the answer is no, acid rain will not burn your skin. This is because the pH level of acid rain is not high enough to cause any damage. In fact, the pH level of acid rain is actually quite similar to that of normal rainwater.

So, if you're ever caught in a downpour of acid rain, don't worry; your skin will be just fine.

Is There Such a Thing as Acid Snow?

The answer to this question is a bit complicated. Acid snow is a type of precipitation that occurs when sulfur dioxide and other acidic pollutants mix with moisture in the atmosphere. This can happen in areas where there is a lot of industrial activity or where there is a volcanic eruption.

Acid snow can have a negative impact on the environment. It can cause trees and plants to lose their leaves when it falls on them. It can also make it harder for fish and other aquatic creatures to survive in affected bodies of water.

So, while acid snow is a real phenomenon, its impact on the environment is something that needs to be monitored closely.

Is Acid Rain an Actual Thing?

Acid rain is an actual phenomenon. It occurs when rainwater becomes unusually acidic, typically as a result of pollutants in the atmosphere. These pollutants can originate from a variety of sources, including power plants, automobiles, and factories. Acid rain can cause a number of environmental problems, such as damage to vegetation, soil erosion, and water contamination.

Can You Drink Acid Rain?

It's a question that many people ask, given the harmful effects of acid rain on the environment. The answer is no, you cannot drink acid rain. The ingestion of water contaminated with acid rain can lead to brain damage over an extended period of time. If you suspect that the water you're drinking may be contaminated, it's important to get it checked out as soon as possible. Brain damage can lead to a whole host of problems, including memory loss, difficulty concentrating, and even depression.


  1. Acid Rain. (n.d.). WonderWorks. Retrieved November 5, 2022, from
  2. Acid Rain | Climate & Weather. (n.d.). Climate and Weather. Retrieved November 5, 2022, from
  3. Acid Rain: What it is, Causes and Consequences. (n.d.). Iberdrola. Retrieved November 5, 2022, from
  4. Australian Bushfires - WWF-Australia. (n.d.). WWF-Australia. Retrieved November 5, 2022, from
  5. Australia's fires 'killed or harmed three billion animals'. (2020, July 28). BBC. Retrieved November 5, 2022, from
  6. Boumis, R. (2019, June 19). Negative Health Effects of Acid Rain on Humans. Sciencing. Retrieved November 5, 2022, from
  7. Dead Forests Release Less Carbon Into Atmosphere Than Expected. (2013, March 22). University of Arizona News. Retrieved November 5, 2022, from
  8. Duncombe, J. (2020, January 13). Five Environmental Consequences of Australia's Fires. Retrieved November 5, 2022, from
  9. Effects of Acid Rain | US EPA. (2022, June 24). EPA. Retrieved November 5, 2022, from
  10. 15 Key Facts and Statistics About Acid Rain. (2017, August 22). Arcadia Blog. Retrieved November 5, 2022, from
  11. Franklin, A. (n.d.). Is there acid snow (like acid rain)? BBC Science Focus Magazine. Retrieved November 5, 2022, from
  12. Krug, E., & Frink, C. (n.d.). Effects of Acid Rain on Soil and Water. Retrieved November 3, 2022, from
  13. Nguyen, D. H. (2018, March 9). How Does Acid Rain Affect Buildings & Statues? Sciencing. Retrieved November 5, 2022, from
  14. Nunez, C. (2019, February 28). Acid rain facts and information. National Geographic. Retrieved November 5, 2022, from
  15. Rose, L., & Boodram, S. (2019, October 21). Catalytic Converters. Let's Talk Science. Retrieved November 5, 2022, from

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2022 Muhammad Rafiq