Environmental Problems, Their Causes, and Sustainability 1

GLOSSARYabiotic Nonliving. Compare biotic.acid See acid solution.acid deposition The falling of acids andacid-forming compounds from the atmosphereto the earth’s surface. Acid depositionis commonly known as acid rain, aterm that refers only to wet deposition ofdroplets of acids and acid-formingcompounds.acid rain See acid deposition.acid solution Any water solution that hasmore hydrogen ions (H ) than hydroxideions (OH ); any water solution with a pHless than 7. Compare basic solution, neutralsolution.active solar heating system System thatuses solar collectors to capture energy fromthe sun and store it as heat for space heatingand water heating. Liquid or air pumpedthrough the collectors transfers the capturedheat to a storage system such as aninsulated water tank or rock bed. Pumps orfans then distribute the stored heat or hotwater throughout a dwelling as needed.Compare passive solar heating system.adaptation Any genetically controlledstructural, physiological, or behavioralcharacteristic that helps an organism surviveand reproduce under a given set ofenvironmental conditions. It usually resultsfrom a beneficial mutation. See biologicalevolution, differential reproduction, mutation,natural selection.adaptive management Flexible managementthat views attempts to solve problemsas experiments, analyzes failures to seewhat went wrong, and tries to modify andimprove an approach before abandoning it.Because of the inherent unpredictability ofcomplex systems, it often uses the precautionaryprinciple as a management tool. Seeprecautionary principle.adaptive radiation Process in whichnumerous new species evolve to fill vacantand new ecological niches in changed environments,usually after a mass extinction.Typically, this takes millions of years.adaptive trait See adaptation.administrative laws Administrative rulesand regulations, executive orders, andenforcement decisions related to the implementationand interpretation of statutorylaws.advanced sewage treatment Specializedchemical and physical processes that reducethe amount of specific pollutants left inwastewater after primary and secondarysewage treatment. This type of treatmentusually is expensive. See also primary sewagetreatment, secondary sewage treatment.aerobic respiration Complex process thatoccurs in the cells of most living organisms,in which nutrient organic molecules such asglucose (C 6 H 12 O 6 ) combine with oxygen(O 2 ) and produce carbon dioxide (CO 2 ),water (H 2 O), and energy. Compare photosynthesis.affluenza Unsustainable addiction tooverconsumption and materialism exhibitedin the lifestyles of affluent consumers inthe United States and other developedcountries.age structure Percentage of the population(or number of people of each sex) ateach age level in a population.agricultural revolution Gradual shiftfrom small, mobile hunting and gatheringbands to settled agricultural communities inwhich people survived by learning how tobreed and raise wild animals and to cultivatewild plants near where they lived. Itbegan 10,000–12,000 years ago. Compareenvironmental revolution, hunter–gatherers,industrial–medical revolution, information andglobalization revolution.agroecology See sustainable agriculture,low-input agriculture, and organic farming.agroforestry Planting trees and cropstogether.air pollution One or more chemicals inhigh enough concentrations in the air toharm humans, other animals, vegetation, ormaterials. Excess heat and noise are alsoconsidered forms of air pollution. Suchchemicals or physical conditions are calledair pollutants. See primary pollutant, secondarypollutant.albedo Ability of a surface to reflect light.alien species See nonnative species.allele Slightly different molecular formfound in a particular gene.alley cropping Planting of crops in stripswith rows of trees or shrubs on each side.alpha particle Positively charged matter,consisting of two neutrons and two protons,that is emitted as a form of radioactivityfrom the nuclei of some radioisotopes. Seealso beta particle, gamma rays.altitude Height above sea level. Comparelatitude.anaerobic respiration Form of cellularrespiration in which some decomposersget the energy they need through thebreakdown of glucose (or other nutrients)in the absence of oxygen. Compare aerobicrespiration.ancient forest See old-growth forest.animal manure Dung and urine of animalsused as a form of organic fertilizer.Compare green manure.annual Plant that grows, sets seed, anddies in one growing season. Compareperennial.anthropocentric Human-centered. Comparebiocentric.aquaculture Growing and harvesting offish and shellfish for human use in freshwaterponds, irrigation ditches, and lakes,or in cages or fenced-in areas of coastallagoons and estuaries. See fish farming, fishranching.aquatic Pertaining to water. Compareterrestrial.aquatic life zone Marine and freshwaterportions of the biosphere. Examples includefreshwater life zones (such as lakes andstreams) and ocean or marine life zones(such as estuaries, coastlines, coral reefs,and the deep ocean).aquifer Porous, water-saturated layers ofsand, gravel, or bedrock that can yield aneconomically significant amount of water.arable land Land that can be cultivated togrow crops.area strip mining Type of surface miningused where the terrain is flat. An earthmoverstrips away the overburden, and apower shovel digs a cut to remove the mineraldeposit. After removal of the mineral,the trench is filled with overburden, and anew cut is made parallel to the previousone. The process is repeated over the entiresite. Compare dredging, mountaintop removal,open-pit mining, subsurface mining.arid Dry. A desert or other area with anarid climate has little precipitation.GLOSSARYG1