Saturday, November 5, 2011
While neutralizing ecosystems that have become acidic, treats the symptoms but not the sources of acidification. Although exact sources of acid rain are difficult to pinpoint and the actual amount of damage caused by acid deposition is uncertain, it is agreed that acid rain levels need to be reduced. Scientific evidence supports the notion that what goes up must come down, and because of public awareness and concerns about acid rain in many countries, politicians have begun to act decisively in controlling or eliminating human causes of such pollution. Emissions of sulfur dioxide and nitrogen oxides are being reduced, especially in Western Europe and North America. For example, in 1992 the governments of the United States and Canada signed an air-quality agreement aimed at reducing acidifying depositions in both countries. While countries in Western Europe and North American have actively carried out actions to reduce emissions of gases leading to acid deposition for a number of years, countries in other parts of the world have only recently addressed the issue. In Eastern Europe, Russia, China, India, Southeast Asia, Mexico, and various developing nations, acid rain and other pollution problems are finally gaining notice. For example, in 1999, scientists identified a haze of air pollution that hovers over the Indian Ocean near Asia during the winter. The 3.8 million-square-mile haze (about the size of the combined area of all fifty American states) is made up of small by-products from the burning of fossil fuels. Such a cloud has the potential to cool Earth, harming both marine and terrestrial life.