Waste and Pollution

Pollution, contamination of Earth’s environment with materials that interfere with human health, the quality of life, or the natural functioning of ecosystems (living organisms and their physical surroundings). Although some environmental pollution is a result of natural causes such as volcanic eruptions, most is caused by human activities. Sidebars | SIDEBAR | Climate Change 2001:The Scientific Basis | The Intergovernmental Panel on Climate Change (IPCC) is an international group of scientists that evaluates scientific and technical information related to climate change and global warming (an increase in Earth’s surface temperature). The IPCC publishes an assessment of the latest scientific data related to climate change about every five years. In its Third Assessment Report, released in January 2001 and summarized here, the IPCC sharply increased its projections, predicting a global average surface temperature rise of 1.4 to 5.8°C (2.5 to 10.4°F) over the period 1990 to 2100 compared to a previous assessment of 1.0 to 3.5°C (1.8 to 6.3°F) for the same period. This IPCC report also for the first time identified human activity as the primary cause for global warming. | open sidebar |
There are two main categories of polluting materials, or pollutants. Biodegradable pollutants are materials, such as sewage, that rapidly decompose by natural processes. These pollutants become a problem when added to the environment faster than they can decompose (see Sewage Disposal). Nondegradable pollutants are materials that either do not decompose or decompose slowly in the natural environment. Once contamination occurs, it is difficult or impossible to remove these pollutants from the environment. Sidebars | HISTORICAL ESSAYS | Health-Care Systems in Post-Colonial Africa | Encarta Historical Essays reflect the knowledge and insight of leading historians. This collection of essays is assembled to support the National Standards for World History. In this