Acids that fall out of the atmosphere are called Acid Rain. Airborne acidic pollutants have highly destructive results. Acid rain is defined as a “rain with a pH of below 4.0 – 4.5.” Normal rain has a pH of about 5.6, which is slightly acidic (In chemistry, pH is a measure of acidity). Acid rain was fist discovered in 1852, when the British chemist Robert Agnus invented the term.
Air quality of the urban areas of Pakistan in general, and of the larger cities of the country with more concentration of vehicular traffic (like Karachi and Lahore) in particular, is deteriorating due to several factors including increasing use of energy. Acid rain and its effects are an issue of intense debate as one of the most pressing environmental problems of the entire world.
How acid rain forms? The invisible gases that cause acid rain mainly come from automobiles or coal burning plants. Once the tiny pollutant molecules have entered the atmosphere, they can travel for thousands of miles. Eventually, the particles will combine with other compounds to produce new, often harmful, chemicals. Acid rain occurs when these gases react in the atmosphere with water, oxygen, and other chemicals to form various acidic compounds. Sunlight increases the rate of most of these reactions. The result is a mild solution of sulfuric acid and nitric acid that falls down to the earth. Once they reach the ground, the acidity in the substance can harm and even destroy both natural ecosystems and man made products. Scientists today are convinced that acid rain is severe in many areas, and that it is having an adverse effect on the environments of those locations.
The problem of acid rain is rapidly spreading. Because industrial processes, automobiles, and power plants mainly cause the problem, those countries that are developed have the most severe acid rain problems. However, as acid rain, sometime also referred to as acid deposition, moves easily, affecting locations far beyond those that let out the pollution. Moreover, when the developing nations begin to industrialize, they also add to the increasing acid rains. Determining just how much the planet is being hurt by acid rain is very difficult because the ecosystems that it affects are so diverse and complex.
Acid rain’s effects are destructive and long lasting. Scientists have studied lakes, streams, and many other natural ecosystems to prove its negative effects. They believe that acid rain continues to be produced and is increasing in many parts of the world.
Modern science has suggested various ways to limit acid rain, and some are now being used in developed world: the installation of sulfur cleaning scrubbers in factories, washing sulfur out of coal, and finding new methods of burning coal. These are all costly but concerned nations are are looking for less expensive solutions to the problem.
Individuals can help by conserving energy, driving their cars less or helping in restoration of damaged environment and more so by being aware of the problem. Governments can pass laws restricting pollution levels, can use a variety of methods such as tradable emission permits to reduce acid rain and ensure implementation of international standards. Whatever way it is done, acid rain will certainly have to be limited in the future.
Choice remains ours!