ABSTRACT
The Organization for Economic Cooperation and Development (OECD) has been collecting and publishing handbooks of environmental indicators since 1991. Human activities treat the environment as a sink for its wastes. Air, earth and water absorb human waste products. Five trace gases that play a major role in raising the earth’s temperature through the greenhouse effect have been combined into their carbon dioxide (CO2) equivalent. The gases are CO2, methane, nitrous oxide, chlorofluoro-carbons (CFCs) and halons. CFCs and halons rise to the stratosphere and deplete the ozone layer, which protects the earth from harmful ultraviolet radiation. Many air pollutants, especially from fossil fuel consumption, add acids to the atmosphere, which can harm buildings, and destroy trees and fish as they fall to earth in rain. Modern industrial society produces many toxic wastes. Radioactive wastes and heavy metals pose the most serious risks. Renewable resources like forests are cut down for timber, fuelwood and for transformation to agricultural use.
