Definition: This entry lists the most pressing and important environmental problems. The following terms and abbreviations are used throughout the entry:
Acidification - the lowering of soil and water pH due to acid precipitation and deposition usually through precipitation; this process disrupts ecosystem nutrient flows and may kill freshwater fish and plants dependent on more neutral or alkaline conditions (see acid rain).
Acid rain - characterized as containing harmful levels of sulfur dioxide or nitrogen oxide; acid rain is damaging and potentially deadly to the earth's fragile ecosystems; acidity is measured using the pH scale where 7 is neutral, values greater than 7 are considered alkaline, and values below 5.6 are considered acid precipitation; note - a pH of 2.4 (the acidity of vinegar) has been measured in rainfall in New England.
Aerosol - a collection of airborne particles dispersed in a gas, smoke, or fog.
Afforestation - converting a bare or agricultural space by planting trees and plants; reforestation involves replanting trees on areas that have been cut or destroyed by fire.
Asbestos - a naturally occurring soft fibrous mineral commonly used in fireproofing materials and considered to be highly carcinogenic in particulate form.
Biodiversity - also biological diversity; the relative number of species, diverse in form and function, at the genetic, organism, community, and ecosystem level; loss of biodiversity reduces an ecosystem's ability to recover from natural or man-induced disruption.
Bio-indicators - a plant or animal species whose presence, abundance, and health reveal the general condition of its habitat.
Biomass - the total weight or volume of living matter in a given area or volume.
Carbon cycle - the term used to describe the exchange of carbon (in various forms, e.g., as carbon dioxide) between the atmosphere,...