Man Made Natural Disaster: Acid Rain

Ozone depletion, greenhouse effect, and acid rain are man-made disasters. The ozone layer is the part of the Earth's atmosphere which contains relatively high concentrations of ozone (O3). The cause of ozone depletion is the presence of Chlorofluorocarbons (CFCs) and related halocarbons gases in the atmosphere. In the presence of Ultraviolet light, these gases dissociate, releasing chlorine atoms, which then go on to catalyze ozone destruction. The greenhouse effect, on the other hand, is a natural warming process of the earth. When the sun's energy reaches the earth some of it is reflected back to space and the rest is absorbed. The absorbed energy warms the earth's surface which then emits heat energy back toward space as longwave radiation. This outgoing longwave radiation is partially trapped by greenhouse gases, such as carbon dioxide (CO2), which then radiate the energy in all directions, warming the earth's surface and atmosphere. Acid rain, or acid precipitation, another man made disaster, occurs when sulfur dioxide (SO2) and nitrogen oxides (NOx) are released into the atmosphere, undergo chemical transformations and are absorbed by water droplets in clouds. The term "acid rain" is used more generally to include all forms of acid deposition. That Acid rain is one of the most dangerous man-made disasters which forms environmental threats is a fact that makes each individual concerns about its stages, causes and effects.

The first stage of acid rain formation is produced when sulfur dioxide (SO2) and nitrogen oxides (NOx) are released into the atmosphere. These fumes are produced by two different sources. The first source is called natural phenomenon which includes forests' fires and volcanoes. When volcanoes erupt they release sulfur dioxide (SO2) and nitrogen compounds. These can create what is called natural acid rain. Natural acid rain is as destructive as industrial created acid rain, but less common. The second source is called man-made fumes, or Industrial fumes, which can be discharged from chemical, energy, and metal factories. Acid rain is most commonly caused by the burning of coal and fossil fuels and from certain industrial processes, which lets off sulfur and nitrogen oxides ("What is Acid Rain", 2002). After fumes, which contain specific chemicals, rise to upper atmosphere, where the wind is very strong, the harmful gases are spread worldwide. In a chemical reaction, oxides combine with water vapor causing nitric and sulfuric acids as a catalyst using sun light. In the last stage, the acid chemicals in the air are blown into areas where they are mixed into clouds. Moreover, the acids can fall to Earth in three forms: rain, snow, or dry particles (dry deposition). In areas where the weather is dry, the acid chemicals may become incorporated into dusts or smokes. Acid rain can damage the environment, human health and property. If the air is dry, acid rain can travel large distances to places that don’t even use fossil fuels. When the acid rain cloud comes in contact with damp or moist air, it will then fall, destroying much in its path (Lioy, 2006).

Acid deposition is dangerous. In fact, acid deposition can be wet, where acidic gases and particles are removed by rain or other precipitation, and it can be dry, where acidic gases and particles are removed by wind to the Earth's surface in the absence of precipitation ("What is Acid Rain", 2002). The question is, "What will happen after deposition?" The effects after deposition won't be only on non living materials but also on living things (Lioy, 2006).

Acid deposition has an effect on non living materials, such as metals. If acids affect metals, which are strong and beautiful, they become weak and delicate. Besides, the shiny surfaces of metals become dull. In a few words, acids are bitter enemies to metals. Stones, on the other hand, which are heavy and beautiful, can be affected by acids. In fact, acids can badly affect the appearance of stones. For instance, if white marbles were affected by acid rains, their white color would change to yellow, black and gray (Lioy, 2006).

Acid rain has an effect on living things as well. Trees derive their nutrition primarily from element ions such as calcium, magnesium, and potassium, which have dissolved from rocks into the soil. Acid deposition adds hydrogen ions, which displace these important nutrients in a process called leaching. Leaching means that the ions are washed deeper into the subsoil or washed out of the top soil. If ions are leached from the soil, they are no longer available to the roots of the plants. Calcium ion is used in the cells of a tree for cell formation and in the processes that transport sugars, water, and other nutrients from the roots to the leaves. Magnesium ion is a vital element in photosynthesis and as a carrier of phosphorus which is important in