# data[].attributes.body
Is the removal and destrucution of forest

# data[].attributes.body
Any form of precipitation with acidic components

# data[].attributes.body
Is the contamination of water bodies.

# data[].attributes.body
The trees are cut down to make way for constructions.

The agriculture is one of the mayor causes

To make anything takes care wood.

# data[].attributes.body
The trees are not being reforested

Loss of natural habits

Poor air quality

# data[].attributes.body
Vehicles and the smoke.

The pollution.

Manufacturing, oil refineries and other industries.

# data[].attributes.body
It's bad for your health.

Damages the forest.

Kills aquatic animals.

# data[].attributes.attachment_link.readable_text
Acid rain, or acid deposition, is a broad term that includes any form of precipitation with acidic components, such as sulfuric or nitric acid that fall to the ground from the atmosphere in wet or dry forms. This can include rain, snow, fog, hail or even dust that is acidic.

Acid rain results when sulfur dioxide (SO ₂) and nitrogen oxides (NO X) are emitted into the atmosphere and transported by wind and air currents. The SO ₂ and NO X react with water, oxygen and other chemicals to form sulfuric and nitric acids. These then mix with water and other materials before falling to the ground.

While a small portion of the SO ₂ and NO X that cause acid rain is from natural sources such as volcanoes, most of it comes from the burning of fossil fuels. The major sources of SO ₂ and NO X in the atmosphere are:

Burning of fossil fuels to generate electricity. Two thirds of SO₂ and one fourth of NOX in the atmosphere come from electric power generators.

Vehicles and heavy equipment.

Manufacturing, oil refineries and other industries.

Winds can blow SO ₂ and NO X over long distances and across borders making acid rain a problem for everyone and not just those who live close to these sources.

Forms of Acid Deposition

Wet Deposition

Wet deposition is what we most commonly think of as acid rain. The sulfuric and nitric acids formed in the atmosphere fall to the ground mixed with rain, snow, fog, or hail.

Dry Deposition

Acidic particles and gases can also deposit from the atmosphere in the absence of moisture as dry deposition. The acidic particles and gases may deposit to surfaces (water bodies, vegetation, buildings) quickly or may react during atmospheric transport to form larger particles that can be harmful to human health. When the accumulated acids are washed off a surface by the next rain, this acidic water flows over and through the ground, and can harm plants and wildlife, such as insects and fish.

The amount of acidity in the atmosphere that deposits to earth through dry deposition depends on the amount of rainfall an area receives. For example, in desert areas the ratio of dry to wet deposition is higher than an area that receives several inches of rain each year.

Measuring Acid Rain

Acidity and alkalinity are measured using a pH scale for which 7.0 is neutral. The lower a substance's pH (less than 7), the more acidic it is; the higher a substance's pH (greater than 7), the more alkaline it is. Normal rain has a pH of about 5.6; it is slightly acidic because carbon dioxide (CO ₂) dissolves into it forming weak carbonic acid. Acid rain usually has a pH between 4.2 and 4.4.

Policymakers, research scientists, ecologists, and modelers rely on the National Atmospheric Deposition Program's (NADP) National Trends Network (NTN) for measurements of wet deposition. The NADP/NTN collects acid rain at more than 250 monitoring sites throughout the US, Canada, Alaska, Hawaii and the US Virgin Islands. Unlike wet deposition, dry deposition is difficult and expensive to measure. Dry deposition estimates for nitrogen and sulfur pollutants are provided by the Clean Air Status and Trends Network (CASTNET). Air concentrations are measured by CASTNET at more than 90 locations.

When acid deposition is washed into lakes and streams, it can cause some to turn acidic. The Long-Term Monitoring (LTM) Network measures and monitors surface water chemistry at over 280 sites to provide valuable information on aquatic ecosystem health and how water bodies respond to changes in acid-causing emissions and acid deposition.

Next, learn about the Effects of Acid Rain.

Or, learn more about:

# data[].attributes.attachment_link.description
Introduction to acid rain including its causes and the different types of acid rain.

# data[].attributes.attachment_link.readable_text
Deforestation is the permanent destruction of forests, which significantly impacts the global carbon cycle and the environment. Forests are critical in regulating the Earth's climate. They store large amounts of carbon dioxide through the process of photosynthesis and are thus carbon sinks. However, deforestation disrupts the carbon cycle by releasing carbon dioxide into the atmosphere and reducing the number of trees that absorb carbon emissions. This effect makes deforestation a major contributor to global greenhouse gas emissions, accounting for around 15% of human-caused emissions.

Deforestation has severe environmental impacts and consequences. Over 420 million hectares of forest have been lost since 1990. The loss of natural habitats and biodiversity has led to a species extinction rate that is 100 to 1,000 times faster than the natural rate. Every second, a forest the size of a football field is cut down, and every year, forested areas equal to the size of Portugal are lost. Clearing forests not only reduces their carbon storage capacity but also increases greenhouse gas emissions due to the reduction of vegetation cover. Deforestation also disrupts water cycles and soil stability, leading to erosion, changes in rainfall patterns, and flooding. Furthermore, deforestation contributes to a loss of ecosystem services and degrades the resources many communities depend on for their livelihoods.
Map of Portugal; Source: ourworldindata.org/deforestation. Help reduce deforestation by offsetting your carbon emissions
This article will explore several causes of deforestation, including the expansion of agricultural land, urbanisation, and increased demand for resources such as timber. Large-scale agriculture is responsible for more than 70% of deforestation globally. The growing population fuels the demand for agricultural land, leading to the clearing of forests to create space for food production. Urbanisation, industrialisation, and infrastructure development have also contributed significantly to deforestation, as growing cities require more land for housing, factories, and transport systems.

What is deforestation

Deforestation is the conversion of forests, through the clearing of trees, to other land uses or the long-term reduction of tree canopy cover to below 10%. Deforestation is often done for commercial or human needs. This removal of forests is a significant contributor to climatic instability and biodiversity loss. Deforestation is therefore one of the most pressing environmental issues facing the world today.

Deforestation occurs due to both natural and human-induced events. Natural events, such as forest fires, hurricanes, and droughts, can destroy forests. However, human activities are the major cause of deforestation.
Plant trees with DGB for a greener future
Deforestation negatively impacts the environment and human life. One of the primary adverse effects is the loss of biodiversity. Deforestation reduces plant and animal habitats, putting them at risk of extinction. Forest loss also leads to soil erosion, which may result in landslides and the contamination of water sources. Deforestation is also a major contributor to climate change. Forests act as carbon sinks, absorbing large amounts of carbon dioxide and other greenhouse gases from the atmosphere. So, when they are cut down through deforestation, the carbon trapped in their biomass is released into the atmosphere. Carbon dioxide is a greenhouse gas that absorbs and radiates heat, causing rising temperatures and changing environmental conditions.

Deforestation is most severe in tropical forests in South and Central America, Africa, and Southeast Asia, where millions of hectares of forest are destroyed each year. Primary forests, which contain the world's most extensive and oldest trees and provide habitats for rare and endangered species, are among the worst affected.
If you want to help mitigate deforestation, invest in nature with DGB
In this article, we will explore the 10 main causes of deforestation, the effects of deforestation, and what we can do to halt current deforestation rates.

1. Expansion of agricultural land

One of the leading causes of deforestation is the expansion of agricultural land, accounting for more than 70% of deforestation rates. Agricultural practices, such as clearing vast areas of forest for farming, logging, and fuelwood use, are primary activities that contribute significantly to deforestation. Both subsistence farming, where farmers grow crops to feed their families, and commercial agriculture, which produces crops for export or domestic use, are responsible for hundreds to thousands of hectares of forest being taken down.

Subsistence farming is common in many countries, and it is often the only way for millions of people to sustain their families. Farmers in these areas typically clear small plots of land by cutting down trees and burning them. Unfortunately, this practice is usually unsustainable, as farmers are forced to clear a larger land surface when the soil becomes infertile. Commercial agriculture, on the other hand, involves clearing vast areas of forest to make way for large-scale production of cash crops like soy and palm oil.

Some of the top agricultural products responsible for deforestation include palm oil, soy, beef, and logging for timber. Palm oil plantations, in particular, have been a major driver of tropical deforestation in Southeast Asia and Central Africa, where vast areas of land have been cleared for oil palm plantations. Soybean cultivation is another significant driver of deforestation in South America, where large swaths of tropical rainforests have been cleared to make way for soy plantations.

The environmental impacts of deforestation caused by agricultural expansion are severe. Forests are critical carbon sinks, and their destruction releases harmful greenhouse gases into the atmosphere. Deforestation also leads to biodiversity loss, destroys the natural balance of ecosystems, and contributes to the habitat loss of many animal species.

2. Livestock grazing

Livestock grazing, particularly for meat production, is also a significant cause of deforestation. Farmers often clear vast areas of land to create grazing pastures for their livestock, contributing to the loss of forested land. The degradation of soil resulting from overgrazing often also leads to repeated clearing and deforestation.
Read more: Livestock running in a field. Cattle ranch Nelore, Brazil. Deforestation in the Amazon Rainforest: causes, effects, solutions
The global demand for meat also drives the expansion of land needed for livestock farming. In addition to pasture land, large amounts of feed crops like soy are grown to feed livestock. In South America, massive forest areas have been cleared to make way for soy plantations, much of which are used to feed livestock. This increase in demand for meat puts tremendous pressure on ecosystems, particularly in the Amazon Rainforest, which is one of the most precious but threatened ecosystems on the planet.

Cattle ranching is one of the primary culprits of deforestation in the Amazon Rainforest. As beef demand increases, farmers are clearing more land for grazing and creating new pastureland. This practice has led to the destruction of millions of hectares of tropical rainforests in the region. In addition, tropical deforestation is driving Indigenous people from their homes and disrupting the natural habitats of native animal species.

One potential solution to the problem of livestock grazing and its impact on deforestation is a shift towards cyclical agriculture. This method involves rotating crops and livestock grazing to maintain soil fertility and avoid overgrazing. In addition, it reduces the need for large areas of pastureland and minimises the pressure placed on forested ecosystems.
Invest in our carbon credits and help restore forests
3. Logging and wood harvesting

Logging and wood harvesting are among the leading causes of deforestation across the world, especially in North America and Russia. Forests are valuable resources that provide timber products for construction, furniture, and paper. Unfortunately, this often leads to unsustainable logging practices that destroy millions of hectares of forested land every year.

Sustainable forestry practices involve selectively harvesting trees and allowing time for the forest to regrow. However, unsustainable logging is a multi-billion-dollar industry fueled by global demand for low-cost timber products. In Indonesia, nearly half of the country's forests have been devastated due to unsustainable logging practices.

When forests are degraded due to logging practices, they become much more vulnerable to conversion to other land uses like mining, agriculture, and settlement. The soil often becomes compacted, making it difficult for new trees to grow. The loss of tree canopy allows for increased sunlight to reach the forest floor, which can spur the growth of invasive species that choke out native flora. Once a forest is degraded, it becomes much easier for developers to obtain permits to clear the land for other uses.

To combat the destructive impacts of logging and wood harvesting, efforts are being made to stop illegal logging, protect forested areas, reform trade agreements, and educate local communities. Protecting forested areas involves creating protected areas, like national parks and wildlife reserves, that are off-limits to logging and other development activities. Reforming trade agreements involves holding companies and countries accountable for their environmental impact and requiring them to adopt sustainable forestry practices. Lastly, educating local communities about the importance of forests and sustainable forest management practices can help change behaviour and prevent further deforestation.

4. Urbanisation and expansion of cities
Read more: Green infrastructure: how nature can improve urban living
Urbanisation and the expansion of cities have a significant impact on deforestation, contributing to the destruction of forested land across the globe. As urban areas grow, they require more resources to sustain their populations, increasing demand for products like beef and agricultural goods. This demand fuels deforestation both directly-through the conversion of forested land into housing or agricultural land-and indirectly-by increasing pressure on forests to provide resources.

The expansion of cities often leads to the need for more land for housing and settlements, as well as for the construction of roads and other infrastructure to service the city. In places like Latin America and Sub-Saharan Africa, the expansion of cities has driven significant forest loss over the past few decades. For example, in the past 20 years, Brazil has lost more than 16 million hectares of forested land to urban expansion, mining, and agriculture, with much of this loss occurring in the Amazon region.
Reduce your environmental impact today
As cities expand and their populations grow, the demand for beef and other agricultural products also increases. In many countries, forests are cleared to make way for grazing land for cattle or the cultivation of crops like soybeans and oil palm. In South America, for instance, the expansion of the beef industry has been a significant driver of deforestation in the Amazon basin. Similarly, in Southeast Asia, the widespread development of palm oil plantations has led to massive deforestation, with an estimated 60% of Indonesia's deforestation being attributable to the palm oil industry.

Not only does urbanisation lead to the direct conversion of forested land for urban development and agriculture, but it also indirectly drives deforestation through the increased demand for resources and the displacement of people from urban areas. For example, farmers may be forced to clear forests to gain more acreage for crop production as land becomes more scarce and valuable due to urban expansion.
Read more: Breathe easy: How trees are nature's air-cleaning machines
5. Human population growth

As the world's population continues to grow, the demand for food, housing, and natural resources also increases. This directly impacts deforestation as the need for more land for agriculture and settlements fuels the conversion of forests into farmland and urban areas.

The expansion of agricultural land is one of the major causes of deforestation worldwide. As the population grows, so does the demand for food, which puts pressure on farmers to clear more land to cultivate crops and raise livestock. This has led to the destruction of vast areas of primary forests, particularly in tropical regions such as Latin America and Southeast Asia.

The need for housing and infrastructure to accommodate the growing population also contributes to deforestation. As populations expand, they encroach upon natural habitats, leading to a loss of forest cover and biodiversity. This harms the environment, as forests are essential for carbon sequestration, biodiversity, and climate regulation.

Human activity, such as livestock grazing and intensive crop cultivation, is also fueled by population growth and contributes to deforestation. In many countries, traditional farming practices have given way to more intensive methods that require fertilisers and machinery. This, in turn, puts pressure on natural resources such as water and contributes to soil erosion and land degradation.

To address these issues, it is important to embrace sustainable living and support organisations that actively work to fight deforestation. By adopting eco-friendly practices and choosing products that are sustainably sourced, we can reduce our environmental impact and protect the world's forests.

6. Increased need for resources

The increased need for resources is a major driver of deforestation. The demand for wood products as well as agricultural products, including palm oil and soybeans, have contributed to unsustainable levels of deforestation.

The global demand for wood products has risen significantly over the years. Timber is used for a wide range of products, including paper, furniture, and building materials. The logging industry has grown substantially to meet this demand, leading to the clearing of large areas of forested land.

Forests provide an extensive range of ecosystem services that cannot be replaced by other mechanisms. These include carbon sequestration, habitat provision, soil health, and air quality preservation. Human activities, increased demand, and expanding populations command more from forests, even though forest areas are shrinking. Taking such services for granted puts an imbalance in the ecosystems and promotes an unsustainable way of understanding and relying on nature.

Agricultural products such as palm oil and soybeans are also major drivers of deforestation. To meet the increasing demand for these products, especially in Asia and South America, vast areas of forests have been cleared to make way for palm oil plantations and soybean fields. This has resulted in extensive forest degradation and biodiversity loss, as well as displacement of Indigenous communities and traditional farming practices.

The resource curse (also the paradox of plenty) is a phenomenon where resource-rich countries face more economic, social, political, and sustainability challenges than countries with fewer resources. In some cases, forests in these countries are cleared to access resources that can be used to generate revenue, often from exporting these resources to other countries (with fewer resources), providing a significant source of income for the 'resource-cursed' country.

However, the economic gains from these resources are often short-term, and unsustainable levels of deforestation can have long-lasting negative impacts on the environment and local communities. To tackle global deforestation, it is thus essential that all countries, governments, and private organisations take action, not only on a local level but also in respect of its resource imports, ensuring that all products acquired are sustainably sourced.
Help restore our vital forests by offsetting your emissions
7. Slash-and-burn techniques

Slash-and-burn techniques, also known as shifting cultivation, are traditional forest-conversion methods that involve clearing forested land by cutting down trees and then burning the area to clear the land for agriculture or timber plantations. This practice has been commonly used in South America, Asia, and Africa for centuries.

The process of slash and burn involves cutting down trees and vegetation in a particular area, leaving them to dry for several weeks, and then setting fire to the debris. The heat from the fire burns the organic matter in the soil, releasing nutrients that can be used to fertilise the land. After the fire has burned out, crops are planted in the nitrogen-rich soil.

While this technique can provide short-term benefits, the consequences of slash-and-burn techniques on forested land can be severe. The removal of trees and vegetation exposes soil to erosion, which can lead to soil depletion and reduced agricultural productivity over time. As the soil loses its fertility, farmers are forced to clear new areas of forested land, perpetuating a cycle of deforestation.
Green ripening soybean field, agricultural landscape. Contribute to ecosystem restoration with our carbon credits
Furthermore, this practice results in large-scale harm to biodiversity, as it wipes out all insects, small reptiles, and other mammals that cannot escape the burnt area. It destroys natural habitats and leads to the displacement of animal species. Burning vegetation also releases large amounts of carbon dioxide and other greenhouse gases into the atmosphere, depleting the forest's carbon stock and highlighting the problem of emissions caused by deforestation.

8. Expansion of manufacturing and industrial sites

The expansion of manufacturing and industrial sites is one of the major drivers of deforestation worldwide. Industrialisation has brought about an increase in the demand for resources such as wood, minerals, and other raw materials. Additionally, biomass power generation, which uses organic materials derived from forests to generate energy and which is the primary energy source in some regions, can be another cause of deforestation if sourced unsustainably. This increase in demand for resources has led to the clearing of forests, resulting in the loss of forest ecosystems and natural habitats.

The consequences of large-scale deforestation for industrial purposes are numerous. Forest ecosystems are complex systems that provide a wide array of benefits, including biodiversity, soil fertility, and carbon sequestration. The loss of forest ecosystems not only results in the displacement of Indigenous communities and animal species but also contributes to increased greenhouse gas emissions.
Read more: The roots of a sustainable future: integrating trees into a circular economy
Some of the key industries responsible for deforestation due to industrial expansion include mining, logging, and oil and gas extraction. Wood production for paper products and agricultural products such as palm oil plantations are also driving deforestation globally. The demand for paper products, including newspapers, books, and packaging materials, has led to the unsustainable harvesting of trees, contributing to deforestation. The expansion of agricultural land, especially for commodities such as soybeans and beef, is another major driver of deforestation in tropical regions.

Mining is another significant cause of deforestation, as it often necessitates clearing vast forested areas to access valuable mineral and metal deposits. The extraction process involves removing vegetation and altering the natural landscape. Additionally, mining operations require extensive infrastructure development, such as building roads or processing facilities. Such further fragmentation of forest habitats creates barriers to wildlife movement patterns and breeding behaviours of species, altering the ecosystems' balance.

The consequences of deforestation for industrial purposes are far-reaching and impact numerous sectors. It affects ecosystems and natural habitats and has implications for biodiversity, soil fertility, and carbon sequestration, threatening both primary and secondary forests. As such, there is a pressing need for concerted efforts from stakeholders to promote sustainable production practices and halt the alarming rate of global deforestation.
Read more: A brown bear drinking water from a forest pond in summer. Preventing desertification: Top 5 success stories
9. Intensive crop cultivation

Intensive crop cultivation is another leading cause of deforestation worldwide. This farming practice involves the cultivation of crops on a large scale, with high inputs of fertilisers, pesticides, and other chemical additives. This method is often used to produce crops such as soybeans and palm oil, which are in high demand for use in animal feed production, particularly livestock, and various other industries. The demand for meat products has dramatically increased, requiring significant amounts of soy and palm oil to feed the animals. As a result, farmers have cleared vast forest areas to make way for soy and palm plantations, leading to a loss of forested lands and the associated ecological services they offer. However, this current productivity rate comes at a cost in the form of deforestation, soil degradation, and biodiversity loss.

New farming methods and techniques have contributed significantly to the rate of deforestation, as farmers use them to expand their crop cultivation. For example, the use of mechanised equipment such as tractors has made it easier to clear large areas of land for cultivation. Moreover, planting and harvesting crops in rotation has led to the cultivation of larger areas of land, thus increasing the rate of deforestation.
Explore DGB's nature-based projects
Cyclic agriculture is a promising approach to maintaining soil fertility while avoiding the harmful effects of intensive farming. The aim of cyclic agriculture is to create a closed system where the nutrients present in the soil are continually recycled, reducing the need for chemical additives and fertilisers. Cyclic agriculture also involves crop rotation, intercropping, and agroforestry, all of which contribute to the growth of soil health and fertility while preserving forested lands. Many other sustainable land management practices can also be implemented to ensure more sustainable crop production, such as regenerative farming and conservation agriculture. At DGB, we incorporate various sustainable agricultural techniques through our projects, such as community-based agroforestry and regenerative farming. This approach helps to restore the environment while helping local communities develop sustainably and economically. When you invest in our projects through our carbon credits, you help restore nature and fight deforestation.
Plant trees for a greener world with DGB
10. Over-exploitation of natural resources
Find out more about our carbon credits
Over-exploitation of natural resources is a major cause of deforestation. This occurs when humans extract more resources than the environment can replenish naturally, leading to the depletion of natural resources such as minerals, fossil fuels, and timber. Activities that contribute to this type of deforestation include mining, logging, and oil and gas extraction.
Make a difference today by investing in DGB's carbon credits
The negative impact of the over-exploitation of natural resources on the environment is significant. When trees are removed from a forested area, the habitats of various animal and plant species are destroyed, leading to a significant loss of biodiversity. Soil erosion also occurs when trees are cut, increasing the amount of sediment that accumulates in rivers and streams. Such sedimentation affects water quality and can lead to further habitat destruction in aquatic environments. Additionally, the release of carbon emissions due to deforestation contributes to an increased carbon footprint associated with human activities.

Minerals, fossil fuels, and timber are some of the most commonly exploited natural resources, contributing greatly to deforestation. Mining for minerals such as gold, silver, and copper often requires clearing large areas of land. Similarly, the demand for fossil fuels, primarily for transportation and electricity generation, has driven companies to extract oil, coal, and natural gas from beneath the earth's surface. As mentioned, the over-exploitation by the logging industry has also led to deforestation, with trees being harvested to produce paper and lumber.

Given the negative impact of over-exploitation of natural resources on the environment, it's important to implement conservation solutions to reduce deforestation. Sustainable forestry practices such as selective cutting and reforestation can help maintain forested lands while still allowing for sustainable timber production. Increasing the number of protected conservation areas can also help prevent further habitat destruction and loss of biodiversity. More fuel-efficient techniques and processes can reduce the strain on forests. Implementing policies that encourage the responsible use of natural resources, such as taxation and regulations, can also help reduce the over-exploitation of natural resources and protect the environment.

Society, and the processes that support it, is consumer-driven. However, over-exploitation has become an everyday occurrence. If we want to ensure a healthy, prosperous future, global action from individuals to governments is needed to create more sustainable practices and protect our planet's resources for future generations.

DGB Group, leading the way for reforestation

DGB Group is a company leading the way for reforestation through nature-based solutions. Our approach to reforestation focuses on restoring degraded forests, promoting sustainable agriculture, and empowering local communities through training and agroforestry. DGB's mission is to help nature prosper and flourish, and that means combatting deforestation by restoring the world's forests.

DGB develops and manages large-scale projects in several countries, including Cameroon, Uganda, and Kenya. We have implemented successful reforestation efforts in these countries by working with local communities , governments , landowners , and investors to restore nature at scale. For example, in Uganda, DGB helps to restore degraded forests in the Hoima, Bulindi, and Masindi districts of western Uganda. This led to increased forest cover and improved habitat for the Bulindi chimpanzees.

DGB's projects generate verified, top-quality carbon credits through the carbon emissions captured through our reforestation efforts. Carbon credits (also known as CO ₂ offset certificates) are a vital tool to restore nature as they fund these vital restoration initiatives and help individuals and organisations achieve carbon neutrality. By investing in our carbon credits, you invest in nature and help to create a greener world.

Join forces with DGB and make a difference through reforestation efforts. Whether you're an individual, investor, or a business, you have the power to make an impact. Let's work together to create a greener world. With your collaboration, we can preserve the world's forests for generations to come.

# data[].attributes.attachment_link.description
Discover the top 10 causes of deforestation, from agricultural expansion to illegal logging, what their effects are and what we can do about it.

# data[].attributes.body
Industry, agriculture and livestock farming.

Fuel spillages.

Maritime traffic.

# data[].attributes.body
Lack of potable water.

Contamination of the food chain.

Destruction of biodiversity.

# data[].attributes.attachment_link.readable_text
What Is Water Pollution?

Water pollution occurs when harmful substances-often chemicals or microorganisms-contaminate a stream, river, lake, ocean, aquifer, or other body of water, degrading water quality and rendering it toxic to humans or the environment.

This widespread problem of water pollution is jeopardizing our health. Unsafe water kills more people each year than war and all other forms of violence combined. Meanwhile, our drinkable water sources are finite: Less than 1 percent of the earth's freshwater is actually accessible to us. Without action, the challenges will only increase by 2050, when global demand for freshwater is expected to be one-third greater than it is now.

What Are the Causes of Water Pollution?

Water is uniquely vulnerable to pollution. Known as a "universal solvent," water is able to dissolve more substances than any other liquid on earth. It's the reason we have Kool-Aid and brilliant blue waterfalls. It's also why water is so easily polluted. Toxic substances from farms, towns, and factories readily dissolve into and mix with it, causing water pollution.

Here are some of the major sources of water pollution worldwide:

Agricultural

Not only is the agricultural sector the biggest consumer of global freshwater resources, with farming and livestock production using about 70 percent of the earth's surface water supplies, but it's also a serious water polluter. Around the world, agriculture is the leading cause of water degradation. In the United States, agricultural pollution is the top source of contamination in rivers and streams, the second-biggest source in wetlands, and the third main source in lakes. It's also a major contributor of contamination to estuaries and groundwater. Every time it rains, fertilizers, pesticides, and animal waste from farms and livestock operations wash nutrients and pathogens-such bacteria and viruses-into our waterways. Nutrient pollution, caused by excess nitrogen and phosphorus in water or air, is the number-one threat to water quality worldwide and can cause algal blooms, a toxic soup of blue-green algae that can be harmful to people and wildlife.

Sewage and wastewater

Used water is wastewater. It comes from our sinks, showers, and toilets (think sewage) and from commercial, industrial, and agricultural activities (think metals, solvents, and toxic sludge). The term also includes stormwater runoff, which occurs when rainfall carries road salts, oil, grease, chemicals, and debris from impermeable surfaces into our waterways

More than 80 percent of the world's wastewater flows back into the environment without being treated or reused, according to the United Nations; in some least-developed countries, the figure tops 95 percent. In the United States, wastewater treatment facilities process about 34 billion gallons of wastewater per day. These facilities reduce the amount of pollutants such as pathogens, phosphorus, and nitrogen in sewage, as well as heavy metals and toxic chemicals in industrial waste, before discharging the treated waters back into waterways. That's when all goes well. But according to EPA estimates, our nation's aging and easily overwhelmed sewage treatment systems also release more than 850 billion gallons of untreated wastewater each year.

Oil pollution

Big spills may dominate headlines, but consumers account for the vast majority of oil pollution in our seas, including oil and gasoline that drips from millions of cars and trucks every day. Moreover, nearly half of the estimated 1 million tons of oil that makes its way into marine environments each year comes not from tanker spills but from land-based sources such as factories, farms, and cities. At sea, tanker spills account for about 10 percent of the oil in waters around the world, while regular operations of the shipping industry-through both legal and illegal discharges-contribute about one-third. Oil is also naturally released from under the ocean floor through fractures known as seeps.

Radioactive substances

Radioactive waste is any pollution that emits radiation beyond what is naturally released by the environment. It's generated by uranium mining, nuclear power plants, and the production and testing of military weapons, as well as by universities and hospitals that use radioactive materials for research and medicine. Radioactive waste can persist in the environment for thousands of years, making disposal a major challenge. Consider the decommissioned Hanford nuclear weapons production site in Washington, where the cleanup of 56 million gallons of radioactive waste is expected to cost more than $100 billion and last through 2060. Accidentally released or improperly disposed of contaminants threaten groundwater, surface water, and marine resources.

Categories of Water Pollution

To address pollution and protect water we need to understand where the pollution is coming from (point source or nonpoint source) and the type of water body its impacting (groundwater, surface water, or ocean water).

Where is the pollution coming from?

Point source pollution

When contamination originates from a single source, it's called point source pollution. Examples include wastewater (also called effluent) discharged legally or illegally by a manufacturer, oil refinery, or wastewater treatment facility, as well as contamination from leaking septic systems, chemical and oil spills, and illegal dumping. The EPA regulates point source pollution by establishing limits on what can be discharged by a facility directly into a body of water. While point source pollution originates from a specific place, it can affect miles of waterways and ocean.

Nonpoint source

Nonpoint source pollution is contamination derived from diffuse sources. These may include agricultural or stormwater runoff or debris blown into waterways from land. Nonpoint source pollution is the leading cause of water pollution in U.S. waters, but it's difficult to regulate, since there's no single, identifiable culprit.

Transboundary

It goes without saying that water pollution can't be contained by a line on a map. Transboundary pollution is the result of contaminated water from one country spilling into the waters of another. Contamination can result from a disaster-like an oil spill-or the slow, downriver creep of industrial, agricultural, or municipal discharge.

What type of water is being impacted?

Groundwater pollution

When rain falls and seeps deep into the earth, filling the cracks, crevices, and porous spaces of an aquifer (basically an underground storehouse of water), it becomes groundwater-one of our least visible but most important natural resources. Nearly 40 percent of Americans rely on groundwater, pumped to the earth's surface, for drinking water. For some folks in rural areas, it's their only freshwater source. Groundwater gets polluted when contaminants-from pesticides and fertilizers to waste leached from landfills and septic systems-make their way into an aquifer, rendering it unsafe for human use. Ridding groundwater of contaminants can be difficult to impossible, as well as costly. Once polluted, an aquifer may be unusable for decades, or even thousands of years. Groundwater can also spread contamination far from the original polluting source as it seeps into streams, lakes, and oceans.

Surface water pollution

Covering about 70 percent of the earth, surface water is what fills our oceans, lakes, rivers, and all those other blue bits on the world map. Surface water from freshwater sources (that is, from sources other than the ocean) accounts for more than 60 percent of the water delivered to American homes. But a significant pool of that water is in peril. According to the most recent surveys on national water quality from the U.S. Environmental Protection Agency, nearly half of our rivers and streams and more than one-third of our lakes are polluted and unfit for swimming, fishing, and drinking. Nutrient pollution, which includes nitrates and phosphates, is the leading type of contamination in these freshwater sources. While plants and animals need these nutrients to grow, they have become a major pollutant due to farm waste and fertilizer runoff. Municipal and industrial waste discharges contribute their fair share of toxins as well. There's also all the random junk that industry and individuals dump directly into waterways.

Ocean water pollution

Eighty percent of ocean pollution (also called marine pollution) originates on land-whether along the coast or far inland. Contaminants such as chemicals, nutrients, and heavy metals are carried from farms, factories, and cities by streams and rivers into our bays and estuaries; from there they travel out to sea. Meanwhile, marine debris- particularly plastic-is blown in by the wind or washed in via storm drains and sewers. Our seas are also sometimes spoiled by oil spills and leaks-big and small-and are consistently soaking up carbon pollution from the air. The ocean absorbs as much as a quarter of man-made carbon emissions.

What Are the Effects of Water Pollution?

On human health

To put it bluntly: Water pollution kills. In fact, it caused 1.8 million deaths in 2015, according to a study published in . Contaminated water can also make you ill. Every year, unsafe water sickens about 1 billion people. And low-income communities are disproportionately at risk because their homes are often closest to the most polluting industries.

Waterborne pathogens, in the form of disease-causing bacteria and viruses from human and animal waste, are a major cause of illness from contaminated drinking water. Diseases spread by unsafe water include cholera, giardia, and typhoid. Even in wealthy nations, accidental or illegal releases from sewage treatment facilities, as well as runoff from farms and urban areas, contribute harmful pathogens to waterways. Thousands of people across the United States are sickened every year by Legionnaires' disease (a severe form of pneumonia contracted from water sources like cooling towers and piped water), with cases cropping up from California's Disneyland to Manhattan's Upper East Side.

Meanwhile, the plight of residents in Flint, Michigan-where cost-cutting measures and aging water infrastructure created a lead contamination crisis-offers a stark look at how dangerous chemical and other industrial pollutants in our water can be. The problem goes far beyond Flint and involves much more than lead, as a wide range of chemical pollutants-from heavy metals such as arsenic and mercury to pesticides and nitrate fertilizers -are getting into our water supplies. Once they're ingested, these toxins can cause a host of health issues, from cancer to hormone disruption to altered brain function. Children and pregnant women are particularly at risk.

Even swimming can pose a risk. Every year, 3.5 million Americans contract health issues such as skin rashes, pinkeye, respiratory infections, and hepatitis from sewage-laden coastal waters, according to EPA estimates.

On the environment

In order to thrive, healthy ecosystems rely on a complex web of animals, plants, bacteria, and fungi-all of which interact, directly or indirectly, with each other. Harm to any of these organisms can create a chain effect, imperiling entire aquatic environments.

When water pollution causes an algal bloom in a lake or marine environment, the proliferation of newly introduced nutrients stimulates plant and algae growth, which in turn reduces oxygen levels in the water. This dearth of oxygen, known as eutrophication, suffocates plants and animals and can create "dead zones," where waters are essentially devoid of life. In certain cases, these harmful algal blooms can also produce neurotoxins that affect wildlife, from whales to sea turtles.

Chemicals and heavy metals from industrial and municipal wastewater contaminate waterways as well. These contaminants are toxic to aquatic life-most often reducing an organism's life span and ability to reproduce-and make their way up the food chain as predator eats prey. That's how tuna and other big fish accumulate high quantities of toxins, such as mercury.

Marine ecosystems are also threatened by marine debris, which can strangle, suffocate, and starve animals. Much of this solid debris, such as plastic bags and soda cans, gets swept into sewers and storm drains and eventually out to sea, turning our oceans into trash soup and sometimes consolidating to form floating garbage patches. Discarded fishing gear and other types of debris are responsible for harming more than 200 different species of marine life.

Meanwhile, ocean acidification is making it tougher for shellfish and coral to survive. Though they absorb about a quarter of the carbon pollution created each year by burning fossil fuels, oceans are becoming more acidic. This process makes it harder for shellfish and other species to build shells and may impact the nervous systems of sharks, clownfish, and other marine life.

What Can You Do to Prevent Water Pollution?

With your actions

We're all accountable to some degree for today's water pollution problem. Fortunately, there are some simple ways you can prevent water contamination or at least limit your contribution to it:

Learn about the unique qualities of water where you live. Where does your water come from? Is the wastewater from your home treated? Where does stormwater flow to? Is your area in a drought? Start building a picture of the situation so you can discover where your actions will have the most impact-and see if your neighbors would be interested in joining in!

Reduce your plastic consumption and reuse or recycle plastic when you can.

Properly dispose of chemical cleaners, oils, and nonbiodegradable items to keep them from going down the drain.

Maintain your car so it doesn't leak oil, antifreeze, or coolant.

If you have a yard, consider landscaping that reduces runoff and avoid applying pesticides and herbicides.

Don't flush your old medications! Dispose of them in the trash to prevent them from entering local waterways.

Be mindful of anything you pour into storm sewers, since that waste often won't be treated before being released into local waterways. If you notice a storm sewer blocked by litter, clean it up to keep that trash out of the water. (You'll also help prevent troublesome street floods in a heavy storm.)

If you have a pup, be sure to pick up its poop.

With your voice

One of the most effective ways to stand up for our waters is to speak out in support of the Clean Water Act, which has helped hold polluters accountable for five decades-despite attempts by destructive industries to gut its authority. But we also need regulations that keep pace with modern-day challenges, including microplastics, PFAS, pharmaceuticals, and other contaminants our wastewater treatment plants weren't built to handle, not to mention polluted water that's dumped untreated.

Tell the federal government, the U.S. Army Corps of Engineers, and your local elected officials that you support water protections and investments in infrastructure, like wastewater treatment, lead-pipe removal programs, and stormwater-abating green infrastructure. Also, learn how you and those around you can get involved in the policymaking process. Our public waterways serve every one of us. We should all have a say in how they're protected.
This story was originally published on May 14, 2018, and has been updated with new information and links.

# data[].attributes.attachment_link.title
Water Pollution: Everything You Need to Know

# data[].attributes.attachment_link.description
Our rivers, reservoirs, lakes, and seas are drowning in chemicals, waste, plastic, and other pollutants. Here's why and what you can do to help.