Glossary 307
environmentalism advocacy of the conservation and maintenance of the natural environment
and the limitation or reversal of human impact on it.
environmental justice environmental actions based on ethical, moral, and spiritual factors
rather than on economic interest or personal preference.
estuary passageway at the lower part of a river where the sea tide meets the river.
ethanol ethyl alcohol made from corn, sugarcane or other plant material that can be used as a
renewable fuel.
ethic value system that defines what is good and bad behavior and sets forth moral duties and
obligations.
eutrophication process by which a body of water becomes very rich in dissolved nutrients (such
as phosphates) either naturally or through pollution that promotes the growth of algae and
other plant life that deplete the dissolved oxygen.
extractivism practice of trying to extract as much of a marketable natural resource as possible.
food chain the order of predation of organisms in which each uses the next, usually lower,
member as a source of food.
food web the totality of interconnecting food chains in an ecosystem.
fossil fuels coal, natural gas, petroleum, and other natural hydrocarbon resources used as fuel.
fracking See hydraulic fracturing.
fuel economy standard set mileage per gallon of fuel required for cars and light trucks.
global warming climate change marked by a worldwide increase in average temperature.
greenhouse effect warming of the lower layers of the atmosphere and of the earth’s surface as a
result of the increase of carbon dioxide and other heat-trapping gases in the atmosphere.
greenhouse gases carbon dioxide, methane, and other gases that allow the sun’s radiant energy
to penetrate the earth’s atmosphere and then prevent the resultant heat from escaping.
green movements wide-ranging social and political activities that focus on ecological issues.
Green Revolution the development and introduction of new varieties of grains, primarily wheat
and rice, that were able to dramatically increase the per acre yield of these crops.
habitat place where an organism or group of organisms lives.
hybrid a plant or animal that is the offspring of parents of two different, but interbreedable,
varieties, species, or genera.
hydraulic facturing (fracking) a drilling process that uses a mixture of water, sand, and chemi-
cals injected deep into the earth at high pressure to blast through underground rock in order
to extract natural gas and oil.
hydroelectric power electric power generated using flowing water as the source of energy.
insecticide any chemical used to destroy insects.
invasive species plant or animal introduced into an ecosystem where it multiplies rapidly and
eventually reduces or replaces native specie populations.