Botkin Environmental Science Earth as Living Planet 8th txtbk

Glossary G-3
deposition of crustal rocks. The carbonate-silicate cycle is
believed to provide important negative feedback mechanisms
that control the temperature of the atmosphere.
Carcinogen Any material that is known to produce cancer in
humans or other animals.
Carnivores Organisms that feed on other live organisms;
usually applied to animals that eat other animals.
Carrying capacity The maximum abundance of a population
or species that can be maintained by a habitat or ecosystem
without degrading the ability of that habitat or ecosystem
to maintain that abundance in the future.
Cash crops Crops grown to be traded in a market.
Catastrophe A situation or event that causes great damage
to people, property or society and from which recovery is
a long and involved process. Also defined as a very serious
disaster.
Catch per unit effort The number of animals caught per unit
of effort, such as the number of fish caught by a fishing
ship per day. It is used to estimate the population abundance
of a species.
Channelization An engineering technique that consists of
straightening, deepening, widening, clearing, or lining
existing stream channels. The purpose is to control floods,
improve drainage, control erosion, or improve navigation.
It is a very controversial practice that may have significant
environmental impacts.
Chaparral A dense scrubland found in areas with Mediterranean
climate (a long warm, dry season and a cooler rainy
season).
Chemical reaction The process in which compounds and
elements undergo a chemical change to become a new substance
or substances.
Chemoautotrophs Autotrophic bacteria that can derive
energy from chemical reactions of simple inorganic
compounds.
Chemosynthesis Synthesis of organic compounds by energy
derived from chemical reactions.
Chimney (or stack) effect A process whereby warmer air
rises in buildings to upper levels and is replaced in the lower
portion of the building by outdoor air drawn through a
variety of openings, such as windows, doors, or cracks in
the foundations and walls.
Chlorofluorocarbons (CFCs) Highly stable compounds
that have been or are being used in spray cans as aerosol
propellants and in refrigeration units (the gas that is compressed
and expanded in a cooling unit). Emissions of chlorofluorocarbons
have been associated with potential global
warming and stratospheric ozone depletion.
Chronic disease A disease that is persistent in a population,
typically occurring in a relatively small but constant
percentage of the population.
Chronic hunger A condition in which there is enough food
available per person to stay alive, but not enough to lead a
satisfactory and productive life.
Chronic patchiness A situation where ecological succession
does not occur. One species may replace another, or an
individual of the first species may replace it, but no overall
general temporal pattern is established. Characteristic of
harsh environments such as deserts.
Classical stability A system characterized by constant conditions
that, if disturbed from those conditions, will return
to it once the factor that disturbed the system has been
removed.
Clay May refer to a mineral family or to a very fine-grained
sediment. It is associated with many environmental problems,
such as shrinking and swelling of soils and sediment pollution.
Clean Air Act Amendments of 1990 Comprehensive regulations
(federal statute) that address acid rain, toxic emissions,
ozone depletion, and automobile exhaust.
Clear-cutting In timber harvesting, the practice of cutting all
trees in a stand at the same time.
Climate The representative or characteristic conditions of the
atmosphere at particular places on Earth. Climate refers
to the average or expected conditions over long periods;
weather refers to the particular conditions at one time in
one place.
Climatic change Change in mean annual temperature and
other aspects of climate over periods of time ranging from
decades to hundreds of years to several million years.
Climate forcing An imposed perturbation of Earth energy
that balance major climatic forcings associated with global
warming. Includes: greenhouse gases, such as carbon dioxide
and methane; reflective aerosols in the atmosphere,
black carbon. Forcing of the climate system also includes
solar activity and Milankovitch Cycles.
Climax stage (or ecological succession) The final stage of
ecological succession and therefore an ecological community
that continues to reproduce itself over time.
Closed system A system in which there are definite boundaries
to mass and energy and thus exchange of these factors with
other systems does not occur.
Closed-canopy forest Forests in which the leaves of adjacent
trees overlap or touch, so that the trees form essentially
continuous cover.
Coal Solid, brittle carbonaceous rock that is one of the
world’s most abundant fossil fuels. It is classified according
to energy content as well as carbon and sulfur content.
Coal gasification Process that converts coal that is relatively
high in sulfur to a gas in order to remove the sulfur.
Cogeneration The capture and use of waste heat; for example,
using waste heat from a power plant to heat adjacent factories
and other buildings.
Cohort All the individuals in a population born during the
same time period. Thus all the people born during the year
2005 represent the world human cohort for that year.
Common law Law derived from custom, judgment, or
decrees of courts rather than from legislation.
Commons Land that belongs to the public, not to individuals.
Historically a part of old English and New England
towns where all the farmers could graze their cattle.
Community, ecological A group of populations of different
species living in the same local area and interacting
with one another. A community is the living portion of an
ecosystem.