IndexIntroductionWhat is acid rain?Effect of acid rainForestsPonds, lakes and streamsEffects of pollutants that cause acid rain on humansEffects of acid rain on artificial materialsWhat is happening doing? ConclusionIntroductionMany human activities, including the burning of fossil fuels, cause pollution. Pollution is the release of harmful substances called pollutants into the environment. Air pollution created by burning fossil fuels doesn't stay in the air forever. However, it can travel long distances and fall back to the ground in the form of dust or rain. When chemicals and pollutants in the air fall to Earth or settle, it is called deposition. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay Acid rain forms when clean rain comes into contact with pollutants in the air, such as sulfur dioxide (SO2), carbon dioxide (CO2), and nitrogen oxides (NOx). Although sulfur dioxide and carbon dioxide are naturally present in the air, burning fossil fuels adds more of these chemicals to the air. When these pollutants are released into the air, they mix and react with water, oxygen and other chemicals to form acid rain. The acid rain then falls to Earth where it can damage plants, animals, soil, water and building materials. What is acid rain? Acid rain can be defined or known as any form of precipitation that is unusually acidic, meaning it has high levels of hydrogen ions. May have harmful effects on plants, aquatic animals and infrastructure. Air pollution causes acid rain. Scientists have found that air pollution from burning fossil fuels is the main cause of acid rain. Power plants and factories burn coal, oil, and natural gas to produce the electricity we need to do all kinds of things, like light our homes and power our factories. Cars, trucks and airplanes also run on gasoline, a fossil fuel that emits smoke and fumes into the atmosphere. In the air, these pollutants combine with moisture to form acid rain. The main chemicals in air pollution that create acid rain are sulfur dioxide (SO2) and nitrogen oxides (NOx). Acid rain usually forms high in the clouds where SO2 and NOx react with water and oxygen. This forms sulfuric acid and nitric acid in the atmosphere. Sunlight increases the speed of these reactions and therefore the amount of acid in the atmosphere. Rainwater, snow, fog, and other forms of precipitation then mix with sulfuric and nitric acids in the air and fall to Earth as acid rain. Effect of Acid Rain Forests Acid rain causes significant damage to forests. It directly affects trees and other plants that are important to the ecosystem as a whole because they are primary producers. Primary producers are organisms that make their own food through photosynthesis, a series of chemical reactions that convert water into sugar using sunlight to provide energy. Plants and some microscopic animals have this ability. Plants are important to ecosystems because they nourish everything else and provide important habitat for other animals. If trees and plants are damaged by acid rain, the effects are felt throughout the ecosystem. Acid rain causes trees in forests to grow more slowly, and in some sensitive species, it caneven cause leaves or needles to turn brown and drop. Spruce and sugar maple, two tree species found primarily in the East and New England, are highly susceptible to damage from acid rain. Acid rain damages trees by dissolving calcium in the soil and tree leaves. This harms the tree because calcium is a mineral that trees need to grow. Once the calcium dissolves, rain washes it away so that trees and other plants cannot use it to grow. Acid rain washes away other minerals and nutrients from the soil in a similar way, causing nutrient deficiency. This is why acid rain can cause trees to grow more slowly. Nutrient deficiency causes other problems for trees and plants. The lack of nutrients weakens trees and makes them more sensitive to cold. A well-nourished tree in healthy soil will survive even a very cold winter with little difficulty, but a tree already weakened by a mineral deficiency may die during a cold winter. Weakened trees and plants are also more susceptible to insects and diseases. At the same time, acid rain causes the release of substances such as aluminum from the soil. Aluminum can be very harmful to trees and plants. Once released into the ground, aluminum can end up in streams, rivers and lakes, where it can harm or even kill fish. Less aluminum is released when precipitation is cleaner. The pollution that causes acid rain also causes haze by scattering light into the sky. Haze reduces the amount of light available for plants to use in photosynthesis. Because photosynthesis is the basis of the food chain, acid rain can cause problems with the movement of nutrients to other organisms in already affected ecosystems. Acid fog further reduces the amount of photosynthesis. Fog can often be more acidic than rain. When leaves are frequently bathed in acid fog, their protective waxy coating can wear away. The loss of this coating damages the leaves and creates brown spots. Leaves are therefore unable to use photosynthesis to transform sunlight energy into food for growth. When leaves are damaged, they cannot produce enough food energy for the tree to remain healthy. Ponds, Lakes and Streams The effects of acid rain are most clearly visible in aquatic environments such as streams, lakes and swamps. Acid rain flows into streams, lakes and swamps after falling on forests, fields, buildings and roads. Acid rain also falls directly on aquatic habitats. Most lakes and streams have a pH between 6 and 8, because the soil's buffering capacity usually neutralizes clean, slightly acidic rain. Lakes and streams become acidic (the pH value drops) when the rainwater itself is so acidic that the surrounding soil cannot buffer the rain enough to neutralize it. For this reason, some lakes in areas where the soil does not have much buffering capacity are naturally acidic even without acid rain. In areas such as the northeastern United States, where soil buffering power is poor, acid rain has made already slightly acidic lakes very acidic, with some lakes having a pH value below 5. As lakes and streams become more acidic, the number and types of fish and other aquatic plants and animals that live in these waters decrease. Some types of plants and animals are able to tolerate acidic water. Others, however, are sensitive to acids and go away or die when the pH drops. Some acidic lakes have no fish because at pH 5 most fish eggs do not.