Glossary
Active Solar Heating System
System that uses solar collectors to capture energy from the sun and store it as heat for space heating and water heating. Liquid or air pumped through the collectors transfers the captured heat to a storage system such as an insulated water tank or rock bed. Pumps or fans then distribute the stored heat or hot water throughout a dwelling as needed.
Advanced Sewage Treatment
Third level of sewage cleanup, which uses a series of specialized chemical and physical processes to remove specific pollutants left in the water after primary and secondary treatment.
Aerobic Respiration
Complex process that occurs in the cells of most living organisms, in which nutrient organic molecules such as glucose (C6H12O6) combine with oxygen (O2) to produce carbon dioxide (CO2), water (H2O), and energy.
Agroforestry
Planting trees and crops together.
Air Pollution
One or more chemicals in high enough concentrations in the air to harm humans, other animals, vegetation, or materials. Excess heat is also considered a form of air pollution. Such chemicals or physical conditions are called air pollutants.
Alley Cropping
Planting of crops in strips with rows of trees or shrubs on each side.
Anaerobic Respiration
Form of cellular respiration in which some decomposers get the energy they need through the breakdown of glucose (or other nutrients) in the absence of oxygen.
Anthropocentric
Human-centered.
Aquatic Life Zone
Marine and freshwater portions of the biosphere. Examples include fresh-water life zones (such as lakes and streams) and ocean or marine life zones (such as estuaries, coastlines, coral reefs, and the open ocean).
Aquifer
Porous, water-saturated layers of sand, gravel, or bedrock that can yield an economically significant amount of water.
Area Strip Mining
Type of surface mining used where the terrain is flat. An earthmover strips away the overburden, and a power shovel digs a cut to remove the mineral deposit. The trench is then filled with overburden, and a new cut is made parallel to the previous one. The process is repeated over the entire site.
Arid
Dry. A desert or other area with an arid climate has little precipitation.
Atmosphere
Whole mass of air surrounding the earth.
Background Extinction
Normal extinction of various species as a result of changes in local environmental conditions.
Bioaccumulation
An increase in the concentration of a chemical in specific organs or tissues at a level higher than would normally be expected.
Biocentric
Life-centered.
Biodegradable
Capable of being broken down by decomposers.
Biodegradable Pollutant
Material that can be broken down into simpler substances (elements and compounds) by bacteria or other decomposers. Paper and most organic wastes such as animal manure are biodegradable but can take decades to biodegrade in modern landfills.
Biodiversity
Variety of different species (species diversity), genetic variability among individuals within each species (genetic diversity), variety of ecosystems (ecological diversity), and functions such as energy flow and matter cycling needed for the survival of species and biological communities (functional diversity).
Biodiversity Hotspots
Areas especially rich in plant species that are found nowhere else and are in great danger of extinction. These areas suffer serious ecological disruption, mostly because of rapid human population growth and the resulting pressure on natural resources.
Biofuel
Gas (such as methane) or liquid fuel (such as ethyl alcohol) made from plant material (biomass).
Biogeochemical Cycle
Natural processes that recycle nutrients in various chemical forms from the nonliving environment to living organisms and then back to the nonliving environment. Examples include the carbon, oxygen, nitrogen, phosphorus, sulfur, and hydrologic cycles.
Biological Pest Control
Control of pest populations by natural predators, parasites, or disease-causing bacteria and viruses (pathogens).
Biomagnification
Increase in concentration of DDT, PCBs, and other slowly degradable, fat-soluble chemicals in organisms at successively higher trophic levels of a food chain or web.
Biomass
Organic matter produced by plants and other photosynthetic producers; total dry weight of all living organisms that can be sup- ported at each trophic level in a food chain or web; dry weight of all organic matter in plants and animals in an ecosystem; plant materials and animal wastes used as fuel.
Biome
Terrestrial regions inhabited by certain types of life, especially vegetation. Examples include various types of deserts, grasslands, and forests.
Biosphere
Zone of the earth where life is found. It consists of parts of the atmosphere (the troposphere), hydrosphere (mostly surface water and groundwater), and lithosphere (mostly soil and surface rocks and sediments on the bottoms of oceans and other bodies of water) where life is found.
Biotic
Living organisms.
Biotic Pollution
The effect of invasive species that can reduce or wipe out populations of many native species and trigger ecological disruptions.
Biotic Potential
Maximum rate at which the population of a given species can increase when there are no limits on its rate of growth.
Broadleaf Deciduous Plants
Plants such as oak and maple trees that survive drought and cold by shedding their leaves and becoming dormant.
Broadleaf Evergreen Plants
Plants that keep most of their broad leaves year-round. An example is the trees found in the canopies of tropical rain forests.
Carbon Capture and Storage (CCS)
Process of removing carbon dioxide gas from coal-burning power and industrial plants and storing it somewhere (usually underground or under the seabed) so that it is not released into the atmosphere, essentially forever.
Carbon Cycle
Cyclic movement of carbon in different chemical forms from the environment to organisms and then back to the environment.
Chemosynthesis
Process in which certain organisms (mostly specialized bacteria) extract inorganic compounds from their environ- ment and convert them into organic nutrient compounds without the presence of sunlight.
Chlorinated hydrocarbon
Organic compound made up of atoms of carbon, hydrogen, and chlorine (Eg.:Â DDT and PCBs).
Chlorofluorocarbons (CFCs)
Organic compounds made up of atoms of carbon, chlorine, and fluorine (Eg.: Freon-12, which is used as a refrigerant in refrigerators and air conditioners). Gaseous CFCs can deplete the ozone layer when they slowly rise into the stratosphere and their chlorine atoms react with ozone molecules.
Chronicle Undernutrition
Condition suffered by people who cannot grow or buy enough food to meet their basic energy needs. Most chronically undernourished children live in developing countries and are likely to suffer from mental retardation and stunted growth and to die from infectious diseases.
Climate
Physical properties of the troposphere of an area based on analysis of its weather records over a long period (at least 30 years). The two main factors determining an area’s climate are its average temperature, with its seasonal variations, and the average amount and distribution of precipitation.
Coal Gasification
Conversion of solid coal to synthetic natural gas (SNG).
Coal Liquefaction
Conversion of solid coal to a liquid hydrocarbon fuel such as synthetic gasoline or methanol.
Coastal Wetland
Land along a coastline, extending inland from an estuary that is covered with salt water all or part of the year (Eg.: marshes, bays, lagoons, tidal flats, and mangrove swamps).
Cogeneration
Production of two useful forms of energy, such as high-temperature heat or steam and electricity, from the same fuel source.
Combined Heat and Power (CHP) production
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Commercial Extinction
Depletion of the population of a wild species used as a resource to a level at which it is no longer profitable to harvest the species.
Commercial Inorganic Fertilizer
Commercially prepared mixture of inorganic plant nutrients such as nitrates, phosphates, and potassium applied to the soil to restore fertility and increase crop yields.
Community
Populations of all species living and interacting in an area at a particular time.
Competition
Two or more individual organisms of a single species (intraspecific competition) or two or more individuals of different species (interspecific competition) attempting to use the same scarce resources in the same ecosystem.
Compost
Partially decomposed organic plant and animal matter used as a soil conditioner or fertilizer.
Conventional-tillage Farming
Crop cultivation method in which a planting surface is made by plowing land, breaking up the exposed soil, and then smoothing the surface.
Coral Reef
Formation produced by massive colonies containing billions of tiny coral animals, called polyps, that secrete a stony substance (calcium carbonate) around themselves for protection. When the corals die, their empty outer skeletons form layers and cause the reef to grow. Coral reefs are found in the coastal zones of warm tropical and subtropical oceans.
Cost–Benefit Analysis
A comparison of estimated costs and benefits of actions such as implementing a pollution control regulation, building a dam on a river, or preserving an area of forest.
Crop Rotation
Planting a field, or an area of a field, with different crops from year to year to reduce soil nutrient depletion. A plant such as corn, tobacco, or cotton, which removes large amounts of nitrogen from the soil, is planted one year. The next year a legume such as soybeans, which adds nitrogen to the soil, is planted.
Crown Fire
Extremely hot forest fire that burns ground vegetation and treetops.
Crude Oil
Gooey liquid consisting mostly of hydrocarbon compounds and small amounts of compounds containing oxygen, sulfur, and nitrogen. Extracted from underground accu- mulations, it is sent to oil refineries, where it is converted to heating oil, diesel fuel, gasoline, tar, and other materials.
Cultural Carrying Capacity
The limit on population growth that would allow most people in an area or the world to live in reasonable comfort and freedom without impairing the ability of the planet to sustain future generations.
Source: Miller, G.T., Spoolman, S.E., 2008. Living in the environment, 16th ed. Brooks Cole