acid rain
Precipitation containing higher than normal amounts of sulfuric acid and nitric acid, formed when natural rainwater combines with sulfur dioxide and nitrogen oxides emitted by burning of fossil fuels.
active solar heating
A system that uses mechanical devices such as pumps or fans to move heated air or liquid between solar collectors and a building.
adaptation
Adjustment in natural or human systems to a new or changing environment.
advanced ecologically engineered system (AEES)
A biological wastewater treatment system which use a series of tanks containing communities of microorganisms, protozoa, higher animals such as snails, and plants.
aerobic
Living systems or processes that occur in the presence of oxygen.
aerosol
Minute solid or liquid airborne particles that remain suspended in the atmosphere for at least several hours.
Agenda 21
An action plan to promote sustainable development by addressing social, economic, and environmental impacts of human activity, adopted by delegates to the 1992 United Nations Conference on Environment and Development, or Earth Summit, in Rio de Janeiro.
aggregate
Coarse particles of rock, used in concrete and paving.
agriculture
The practice of cultivating plants and animals for food and fiber.
agroecology
An interdisciplinary approach which applies principles of ecology to the practice of agriculture.
agroforestry
The intercropping of annual or perennial agricultural crops with trees or other woody plants.
albedo
A measure of a surface’s ability to reflect sunlight, often expressed as a decimal fraction on a scale of 0 to 1.
allergen
A substance that activates the body’s immune system, causing a response when a response is not necessary.
alternative energy
An energy source that is an alternative to fossil fuels.
anaerobic
Living systems or processes that occur in the absence of oxygen.
Anthropocene
An informal term for the most recent period in Earth’s history during which human activities have had significant impact on climate and ecosystems.
anthropocentrism
A view of reality in which human values and interests are primary.
anthropogenic
Resulting from human activities.
aquaculture
The industrial farming of fish or seafood.
aquifer
An underground water-bearing layer of permeable rock, sand, or gravel capable of supplying wells or springs.
background rate of extinction
The normal rate at which species go extinct in the absence of human factors.
barrel (bbl)
A liquid volume equal to 42 US gallons, used to indicate quantities of petroleum products.
benthic organism
An organism that lives on the bottom of a water body.
bioaccumulation
The process in which the concentration of a substance taken in by an organism increases faster than the rate at which the organism can remove it.
bioaugmentation
The addition of microorganisms to a polluted site to assist in bioremediation.
biocentrism
A view of reality in which all living things have intrinsic value and are morally considerable.
biochemical oxygen demand (BOD)
A measure of organic content in water, given by the amount of dissolved oxygen consumed by aquatic organisms as they break down organic matter.
biodiesel
A fuel made of oils from plant materials or animal fats and used as a diesel fuel substitute or diesel fuel extender.
biodiversity hotspot
One of several areas that contains an especially great diversity of endemic species facing a high risk of extinction.
biodiversity
The variety of genes, species and ecosystems found in a particular area.
biofuel
A liquid fuel made of plant material and used as a partial substitute for gasoline.
biogas
A gas generated by the decomposition of organic waste.
biogeochemical cycle
The movement of matter in cycles through the atmosphere, lithosphere, hydrosphere, and biosphere. Examples include the carbon cycle and the hydrologic cycle.
biointensive agriculture
An approach to producing high yields of food crops in small spaces using raised beds; also known as French intensive agriculture.
biomagnification
The process in which the concentration of a substance increases as it passes to successively higher trophic levels of a food web.
biomass
Biology: The total weight of all living organisms in a particular area.
Renewable energy: Plant or animal material, often wood or grasses, that can be converted into energy through burning or through conversion into a gas or liquid fuel which is then burned.
biome
A major regional habitat type characterized by particular climate and soil conditions and particular biological communities.
biomimicry
An approach to designing products or buildings using nature as a model.
biophilia
The genetically encoded emotional need of human beings to affiliate with nature and with other living organisms, rooted in human biology and evolution.
biophilic design
An approach to designing the built environment in ways that connect people with the natural world.
bioreactor see membrane bioreactor
bioregion
An area with similar climate, topography, plant and animal communities.
bioremediation
The use of microorganisms to break down pollutants in soil or water.
biosphere
The part of the Earth system on land, in the oceans, and in the atmosphere inhabited by living organisms.
bioswale
A vegetated linear depression used to cleanse and infiltrate stormwater.
birth rate
The total number of people born in a given year.
black swan
A large-scale event that could not have been predicted.
Blackwater
Wastewater from toilets, kitchen sinks, and dishwashers.
BREEAM
The Building Research Establishment Environmental Assessment Method, a green building rating system developed in the UK and used in Europe.
brood parasite
A bird that lays its eggs in the nest of another bird, which then cares for the offspring.
brownfield
An abandoned or under-used industrial site in which redevelopment or reuse is complicated by the presence or potential presence of a hazardous material.
CAFO
Acronym for concentrated animal feeding operation, an industrial-scale facility for housing animals at high densities for feeding prior to slaughter; also known as a feedlot.
cancer cluster
A greater-than-expected number of cancer cases in a particular location, usually associated with exposures to toxins in the workplace.
cap and trade
The buying and selling of permits to pollute; also known as emissions trading.
capital
The supply of resources available.
capital project
A long-term investment in the improvement of a fixed asset, such as a building or infrastructure, requiring a comparatively high financial outlay.
carbon capture and sequestration (CCS)
Technology which removes carbon dioxide from industrial processes and stores it underground or under the ocean floor.
carbon dioxide equivalent (CO2e)
The climate impact of a greenhouse gas expressed as the tons of carbon dioxide that would result in the same impact; determined by multiplying the tons of the given gas by its global warming potential.
carbon footprint
A measure of greenhouse gas emissions associated with an activity; technically expressed as area of land needed for carbon dioxide sequestration, but often used more loosely to mean the quantity of greenhouse gases emitted, measured in tons.
carbon neutral
Living or doing business in a way which results in no net carbon emissions; also known as climate neutral.
carbon sequestration
The removal and storage of carbon in a carbon sink through biological or physical processes.
carcinogen
A substance known to increase the risk of developing cancer.
carrying capacity
The maximum number of individuals that a given environment can support indefinitely.
CERCLA
The Comprehensive Environmental Response, Compensation, and Liability Act, also known Superfund, U.S. law which regulates wastes on land and in navigable waters.
certification
A procedure by which a third party verifies the level of performance of a product, process or service compared to some standard.
chaos theory
The mathematical theory that very small changes in the initial state of a system lead to large and unpredictable effects. See also nonlinearity.
charrette
A fast-paced planning process in which participation by multiple stakeholders produces a collaborative solution.
chlorofluorocarbons (CFCs)
Chemical compounds containing atoms of carbon, chlorine, and fluorine that are harmful to the ozone layer of the atmosphere.
circular economy
A closed-loop economy with a continuous cyclic flow of materials, where output from one process becomes input for another.
clathrate see methane hydrate
climate change
A significant change in measures of climate such as temperature, precipitation, and wind lasting for an extended period of time; can result from natural processes or human activity.
climate commitment
The climate change that would still occur even with no further human influence, resulting from greenhouse gases already emitted.
climate neutral
Living or doing business in a way which results in no net climate impact; also known as carbon neutral.
climax community
Historic term for a community resulting from a process of ecological succession that remains unchanged in the absence of disturbance.
closed loop
A cyclical system of production in which the concept of waste is eliminated.
cob
A composite mixture of clay, sand, straw, and water used as a building material which is built up by hand.
cogeneration see combined heat and power
combined heat and power (CHP)
The production of electricity and useful heat using a common energy source.
commissioning
The systematic process of verifying and documenting that building systems are functioning as intended.
common pool resources (CPRs)
Resources from which it is difficult to exclude or limit users and in which use of the resources by one person decreases the benefits for other users.
commons
A common pool resource plus a community plus a set of protocols: the rules and social practices for managing the resources.
community
A group of interacting species living in a particular area.
community garden
A piece of land on which food is grown by a group of people.
community-supported agriculture (CSA)
An approach to supplying food in which customers buy subscriptions to local farms in return for regular deliveries of shares of the harvests.
compact fluorescent light
A small fluorescent lamp used as a replacement for a screw-in incandescent bulb.
compaction
A process in which particles of soil are pushed together and the pore spaces between them are reduced in size or closed off.
complex adaptive system
A self-organizing system of interacting elements, regulated by feedbacks and resulting in emergent behavior.
complexity
A term used to characterize interacting relationships in a system in which simple rules of cause and effect do not apply and outcomes are not predictable.
compost
Decomposed organic matter which has been broken down by microorganisms in a controlled environment.
consensus
The outcome of a group decision-making process in which the views of each participant have been heard and considered and the resolution is one that can be supported by every participant.
conservation
Activity to maintain biodiversity and ecosystem function in a particular area. Also, a term used in the early twentieth century to mean a view of nature as a resource to be efficiently managed for human use.
conservation agriculture
An approach to growing crops based on 3 principles: crop rotation, protecting soil with cover crops and retained crop residue, and no-till.
conservation banking
A mechanism similar to wetland mitigation banking in which habitat areas are set aside to compensate for habitat that is destroyed elsewhere; banked habitats provide credits which can be bought and sold.
conservation biology
A scientific discipline that focuses on the preservation of biodiversity.
conservation easement
A legal agreement in which a landowner retains ownership of their property but permanently relinquishes the right to build on or develop the property, often in exchange for financial or tax benefit.
constructed wetland
A wetland feature engineered to use natural processes of plants, soils, and bacteria living in association with wetland plant roots for the purpose of water or wastewater treatment.
conventional pollutants
Major water pollutants regulated by the U.S. Clean Water Act: biochemical oxygen demand, total suspended solids, fecal coliform bacteria, pH, and oil and grease.
cool roof
A roof covered with material which reflects rather than absorbs sunlight.
corporate social responsibility
The voluntary commitment of a business to take responsibility for the social, economic, and environmental impacts of its activities.
corridor see habitat corridor
cradle to cradle
A design approach in which materials are thought of as nutrients which recycle continuously.
cradle to grave
The life cycle of a product or material from production to disposal, excluding recycling or reuse.
criteria pollutants
Major air pollutants regulated by the U.S. Clean Air Act: particulates, carbon monoxide, sulfur oxides, nitrogen oxides, lead, and ground-level ozone.
critical root zone
The area around a tree within which soil must be protected from excavation or compaction; also known as the tree protection zone.
cryosphere
Earth’s ice and snow cover.
daylighting
Buildings: The use of natural sunlight for illumination in order to reduce or eliminate electric lighting.
Stream restoration: The act of returning a buried stream to the surface and allowing it to flow aboveground.
decoupling
The condition in which development occurs without increases in environmental impact.
de-listing
The removal of a formerly endangered species from the list of endangered species.
demographic transition
The shift from high birth rates and death rates to low birth rates and death rates in developed countries.
demography
A field of social science that applies the principles of population ecology to human populations.
design for environment
The practice of designing products and manufacturing processes in environmentally responsible ways.
development
An increase in the quality of goods and services, with or without quantitative growth; development is a qualitative measure.
diatomic
A molecule composed of two atoms.
disturbance
A natural or human-caused event such as fire, flood, or urban development that changes the structure and function of an ecosystem.
downcycling
A characteristic of reprocessing a material in which the quality of the material decreases over time.
dump
A place where waste is deposited without further treatment or protection.
Earth system
The total complex of atmosphere, hydrosphere, lithosphere, and biosphere that influence conditions at the Earth’s surface.
ecobabble
Speech which uses the technical language of ecology to make the user appear ecologically aware.
ecocentrism
A view of reality in which ecosystems or biotic communities, and not just individuals, have intrinsic value and are morally considerable.
eco-district
A collaborative planning approach to sustainable development at a neighborhood scale.
eco-efficiency
An approach to product and process design that seeks to minimize material consumption, waste, and pollution.
eco-industrial park
A complex of industrial facilities which applies the principles of industrial ecology in an industrial ecosystem.
eco-label
A label which gives information about a product or service in terms of its environmental or social impacts.
ecolinguistics
A subdiscipline of linguistics which studies the role of language in environmental problems and solutions.
ecological economics
A discipline that merges economics and ecology and conceives of the economy as a subsystem of the Earth ecosystem.
ecological footprint
A measure of the demand a person, population, or activity places on nature in order to produce the resources it consumes and to absorb the waste it generates, usually expressed as acres or hectares of productive land and water.
ecological restoration
Activity to assist the recovery of degraded biodiversity and ecosystem function in a particular area.
ecological rucksack
The total weight of material “carried” by a product; the material displaced in order to extract, process, and use the material over the course of its lifetime.
ecology
The study of the relationships between organisms and their environment.
ecoregion
A physical area with a particular combination of environmental conditions, including climate, topography, geology, and vegetation.
ecosystem
A system of living organisms interacting with each other and their physical environment.
ecosystem services
The essential benefits people obtain from ecosystem processes.
edge effects
Altered environmental conditions that impact organisms living near the edge of a fragmented habitat.
elevator speech
A concise summary, brief enough to be conveyed within a 30-second elevator trip.
embodied energy
The total energy used to produce, transport, and dispose of a product.
emergence
The spontaneous appearance of novel properties at the level of a system that cannot be predicted by knowledge of the system’s parts.
emissions trading
The buying and selling of permits to pollute; also known as cap and trade.
endangered species
A species considered to be facing a high risk of extinction in the wild in the near future.
endocrine disruptor
A pollutant that interferes with normal hormone functions.
energy
The ability to do work
energy audit
A systematic, detailed analysis of how and where a building uses energy.
energy efficiency
Using less energy to perform the same tasks.
energy service
The amount of useful work done by each unit of fuel.
energy services company (ESCO)
A company which provides measurement and verification and energy efficiency services for a building and whose fees are paid for out of the energy savings.
energy utilization index (EUI)
An index used to measure building efficiency, usually expressed as a ratio of Btu per square foot of gross floor area per year.
entropy
The degree of disorder in a system.
environment
All the living and nonliving external conditions that affect and interact with organisms, populations, or other living systems.
environmental ethics
The branch of philosophy that studies the moral value of, and humans’ ethical relationship to, the nonhuman world.
environmental health
The discipline which studies the effects of environmental factors on human health.
environmental history
The study of human relationships to the natural world through time.
environmental impact statement
A document that outlines the positive and negative environmental impacts of a proposed action, together with one or more alternative actions, as an aid to decision-making.
environmental justice
The concept that access to a clean, healthy environment is a fundamental human right.
environmental management system (EMS)
A formal system within an organization for developing, implementing, and maintaining environmental policies and procedures.
equilibrium
The state of a system in which opposing influences are balanced and in which the system will remain unless disturbed.
equity
The fair distribution of resources and opportunities to all people which enables them to reach an equal outcome.
erosion
A process in which rock or soil is loosened, removed, and transported from one place to another by the action of water, wind, or other natural agents.
eutrophication
Accelerated plant growth and decay in aquatic environments caused by nitrogen and phosphorus pollution and resulting in oxygen depletion.
evidence-based design
An approach to designing the built environment in which decisions are based on the best available current research evidence.
e-waste
Discarded electrical or electronic equipment.
experiential learning
Education which involves learning by doing.
externality
A cost which is external to the entity creating the damage and not reflected in the price.
extinction
The death of all individuals within a species.
Factor 4
A concept which proposes that humans should reduce their consumption of resources to one-fourth of the current levels in order not to exceed the planet’s carrying capacity.
Factor 10
A concept which proposes that humans should reduce their consumption of resources to one-tenth of the current levels in order not to exceed the planet’s carrying capacity.
factory farm
A large-scale animal factory.
failed state
A state, or self-governing political body, in which the ability to govern has broken down.
failing state
A state which is in the process of breaking down toward a failed state.
fate
The description of how a pollutant changes over time.
fecal coliform bacteria
A group of bacteria found in the feces of humans and other animals which are used as indicators of disease-causing bacteria.
feebate
A system that taxes socially undesirable activities and products and uses the money to support more desirable ones; a recently coined word combining “fee” and “rebate.”
feedback
A circular mechanism in which the result of an initial process triggers changes in a second process that in turn influence the initial process. An interaction which increases or amplifies the original change is called positive feedback; an interaction which decreases the original change is called negative feedback.
feedlot
An industrial-scale facility for housing animals at high densities for feeding prior to slaughter; also known as a CAFO.
fertility rate see total fertility rate
first flush
The initial quantity of water that runs off a surface at the beginning of a rainstorm.
floodplain
The flat area adjacent to a river or stream that is subject to period flooding.
food chain
A linear sequence of feeding relationships.
food desert
An urban area in which residents do not have ready access to healthy food.
food forest
A small-scale form of agroforestry in a multi-story combination of food-bearing trees, shrubs, perennials, and annuals.
food miles
The distance from where a product is grown to where it is eaten.
food security
The state of having access at all times to sufficient, nutritionally adequate, and safe foods that meet dietary needs and food preferences.
food sovereignty
The right of people to healthy and culturally appropriate food along with their right to define their own food and agriculture systems.
food web
A network of feeding relationships in an ecosystem.
foodshed
A geographic area within which the food for a population is produced, transported, and consumed.
foraging
The practice of gathering food found in public or common spaces.
fossil fuel
Combustible geologic deposits formed from partially decomposed remains of organisms trapped in the Earth’s crust and converted to coal, oil, and natural gas by exposure to heat and pressure.
fracking see hydraulic fracturing
fragmentation
The breaking up of a habitat patch into two or more smaller pieces, usually by human activities such as agriculture, urban development, or roads.
fuel cell
A device that generates an electrical current by converting the chemical energy of a fuel supplied from outside the cell into electrical energy.
fuel switching
Substituting one fuel for another to do the same task.
Gaia theory
The theory that the Earth is an evolving, self-regulating system that maintains conditions favorable to life.
gap analysis
Comparing conservation goals, biophysical data, and existing protected areas to identify gaps in ecosystem protection.
generator
A device that converts mechanical energy into electrical energy.
genetic drift
The gradual loss of genetic variation in a small population due to random events.
genetically modified organism (GMO)
An organism whose genetic code has been altered in a way that could not have occurred naturally by mating or recombination.
Genuine Progress Indicator
A measure of economic progress that considers improvement in well-being and quality of life, proposed as an alternative to Gross Domestic Product.
geographic information systems (GIS)
Computer software which combines maps and databases, with information stored on layers.
gleaning
The practice of gathering food from leftover crops in farmers’ fields.
global warming potential (GWP)
A ratio that indicates the greenhouse effect of a particular gas relative to that of the same quantity of carbon dioxide over a fixed period of time, usually 100 years.
global warming
An average increase in the temperature of the atmosphere near the Earth’s surface.
governance
The process of decision-making by which an organization or society regulates activities and exercises control over resources; often refers to collective actions of multiple stakeholders working together in order to achieve common goals.
graywater
Untreated wastewater collected from bathroom sinks, showers, bathtubs, and clothes washers which has not come into contact with toilet waste.
green building
An energy- and water-efficient building made of nontoxic and often locally-sourced materials that is environmentally responsible and healthy for its occupants; also known as a high-performance building.
green chemistry
The use of chemical materials and processes with little or no toxicity.
green revolution
The intensification of global food production in the mid-twentieth century based on technologies such as fertilizers, pesticides, irrigation, and high-yield crop varieties.
green roof
A kind of roof covering made of a waterproof layer, growing medium, and plants.
greenfield
Open space that has never been built upon.
greenhouse effect
The warming of a planet’s surface as a result of certain atmospheric gases which absorb some of the infrared solar radiation that would otherwise escape into space and re-radiate this energy back to the surface.
greenhouse gas
A gas that absorbs infrared radiation in the atmosphere; greenhouse gases include water vapor, carbon dioxide, methane, nitrous oxide, ozone, and others.
greenwashing
The use of deliberately misleading terms in order to portray an environmentally responsible image.
grid
A network of interconnected transmission and distribution lines that distributes electricity from power generation stations to users.
gross domestic product (GDP)
A measure of economic growth consisting of the total value of goods and services produced within the boundaries of a country.
groundwater
Water that has accumulated in saturated soil or rock below the Earth’s surface.
growth
An increase in size or an increase in production; growth is a quantitative measure.
habitat
The physical environment where an organism lives and finds food, water, cover, and space to grow and reproduce.
habitat corridor
A linear landscape element that connects otherwise isolated habitat patches, allowing movement and dispersal.
habitat fragmentation see fragmentation
habitat patch
A discrete area large enough to support breeding by a particular species.
hazard
A phenomenon or activity that can cause damage, disease, injury, or death.
hazardous air pollutants (HAPs)
A list of chemicals identified by the EPA which are considered particularly dangerous.
hazardous waste
A substance which has been discarded which poses a risk to humans or the environment.
heat island see urban heat island effect
heat pump
A refrigeration machine with a reversing valve, used to transfer heat into a building to provide heating or out of a building to provide cooling.
heavy metals
Metals which have high atomic weight, such as lead, mercury, and arsenic.
high-performance building
An energy- and water-efficient building made of nontoxic and often locally-sourced materials that is environmentally responsible and healthy for its occupants; also known as a green building.
hotspot see biodiversity hotspot
homegarden
A food forest in a tropical region.
HVAC
Acronym for heating, ventilation, and air-conditioning, the system or systems that condition air in a building.
hydraulic fracturing
The fracturing of fossil fuel-bearing rock using fluids injected underground at high pressures. Also known as fracking.
hyperaccumulator
A plant which can accumulate larger amounts of micronutrients than most other plants.
hyporheic zone
The subsurface environment below a stream channel.
hypothesis
The first step in the scientific method, a proposed explanation of a phenomenon that can be tested scientifically.
in Situ
In its original position, from the Latin phrase meaning “in position.”
index
A composite indicator which combines multiple sources of data into one number.
indicator
A representative factor which indicates the condition or functioning of a characteristic or a system, used to measure progress toward to a goal.
indicator species
A species whose presence indicates particular environmental conditions.
industrial ecology
An approach to the design of products and processes that helps an industrial system behave like an ecosystem, where the output from one industry is the input for another.
industrial symbiosis
A network of exchanges in which the output from one industry is the input for another.
industrialized agriculture
Large-scale farming using fossil fuel-driven machinery, large amounts of irrigation water, synthetic fertilizers, pesticides, and monoculture planting; also known as agribusiness.
infiltration
The process in which rainwater flows through or is absorbed by pores in soil.
infrastructure
The technological support systems used to transport people, goods, water, waste, energy, and information in human communities.
instrumental value The assumption that a thing is valuable only insofar as it benefits humans.
integrated pest management (IPM)
An ecologically based strategy which controls insects with minimal use of pesticides.
intergenerational equity
The concept that all human generations, including present and future, have an equal right to a stable climate and healthy biosphere.
intrinsic value
The assumption that a thing has value in and for itself, regardless of its usefulness to humans.
invasive species
A species introduced outside its normal distribution which increases in abundance at the expense of native species, interfering with an ecosystem’s normal functioning.
irradiation
A food processing method in which food is exposed to a dose of radiation for the purpose of killing pathogenic bacteria and insects by disrupting their DNA.
No entries.
keystone species
A species so critical to an ecosystem that its removal could cause major disruption for the whole ecosystem.
knowledge capital
A community’s or cultural group’s store of knowledge, skills, and understanding of the places where they live.
Kyoto Protocol
An international treaty adopted in 1997 at the United Nations Framework Convention on Climate Change and expiring in 2012 which limited carbon dioxide emissions for those developed countries that signed it.
land trust
A nonprofit organization that works to acquire land, to help others acquire land or conservation easements, and to provide stewardship.
landfarming
A type of bioremediation in which waste or contaminated soil is spread in a thin layer on the land so that it is easily accessible by aerobic soil microorganisms.
landfill
A waste disposal site for long-term storage of solid waste in which waste is buried. See also sanitary landfill.
leachate
Liquid in a landfill consisting of rainwater, liquid from organic waste, and dissolved pollutants.
LEED
Leadership in Energy and Environmental Design, a green building certification system.
life cycle assessment
A method for quantifying the total environmental impacts of a material, product, or building through all phases of its life from cradle to grave; also known as life cycle analysis.
LED
Light-emitting diode; a semiconductor device used for lighting which consumes less energy and lasts longer than other current lighting technologies.
listing
The addition of a species considered to be facing a high risk of extinction to a list of endangered species such as the international IUCN Red List or the lists maintained by the US Fish and Wildlife Service and National Marine Fisheries Service, mandated by the US Endangered Species Act.
Living Building
A stringent green building certification system based on the Living Building Challenge.
Living Machine
A proprietary biological wastewater treatment system which use a series of tanks containing communities of bacteria, plants, and animals. A brand of advanced ecologically engineered systems (AEES) now known as the Eco-Machine.
locavore
A person who eats primarily locally produced food.
low-hanging fruit
An informal term used to describe targets which are easy to achieve and which carry no or low cost.
mass extinction
An extraordinary extinction event in which a large proportion of the world’s species become extinct in a relatively short time period
matter
Any physical substance; something which occupies space and has mass.
measurement and verification (M&V)
A written plan which verifies that investments in energy efficiency measures are providing the benefits expected.
membrane bioreactor
A compact device for wastewater treatment consisting of a series of tanks where bacteria living on membranes break down nutrients.
metapopulation
A collection of local populations of the same species linked by some degree of migration; a “population of populations.”
methane hydrate
A partly frozen mix of methane gas and ice, usually found in sediments.
microplastic
Particles of synthetic plastic which are smaller than a few millimeters.
microtopography
Small-scale variations in the shape of the surface of the land, resulting in a diversity of microhabitats.
Milankovitch cycles
Regularly recurring changes in the tilt of Earth’s axis, precession of Earth’s axis, and eccentricity of Earth’s orbit which influence cycles of cooling and warming climate.
mitigation
Climate change: Measures undertaken to minimize the extent or impact of a problem such as climate change.
Habitat: A mechanism in which a damaged habitat is rehabilitated or an intact habitat area is set aside to compensate for habitat that is destroyed elsewhere.
monoculture
The planting of a single crop over a large area.
Montreal Protocol
An international treaty signed in 1987 which phases out the production and use of ozone-depleting chlorofluorocarbons.
moral standing The status of an entity whose interests matter intrinsically and must be given consideration in the moral assessment of actions and events.
mulch
A layer of organic material spread over the surface of soil.
municipal solid waste (MSW)
Waste from households, offices, institutions, and small businesses; called ‘municipal’ because such waste is the responsibility of local governments.
mutagen
A substance which damages genetic material, or DNA, in cells.
mycoremediation
The use of fungi to break down contaminants.
mycorrhizae
A symbiotic relationship between the roots of most plants and certain fungi.
nanoplastic
Particles of synthetic plastic which are smaller than a few micrometers.
native species
Species that developed in the place where they live and are adapted to conditions there.
natural capital
Environmental resources and ecosystem services that make all economic activity possible.
nest predation
The action of predators who eat juvenile birds in the nest.
net metering
A billing arrangement that allows customers who generate their own electricity to sell excess electricity to the local power utility.
net zero carbon
The condition in which the amount of CO2 entering the atmosphere equals the amount that is removed.
net zero energy
A net-zero energy building is one which produces as much energy as it uses over the course of a year.
neurotoxin
A toxin that damages the nervous system.
New Urbanism
An urban design movement similar to smart growth promoted by the Congress for the New Urbanism.
niche
The role an organism plays in its ecosystem.
nonlinearity
A condition in which there is no simple proportional relationship between cause and effect.
nonpoint source
A diffuse source of pollutants that cannot be tied to a specific point of origin.
nonrenewable resource
A natural resource with a finite supply that cannot be replaced once used, or one that cannot be replaced as fast as it is consumed.
no-till farming
An approach to growing crops by planting in undisturbed soil covered by crop residues and other mulch.
novel ecosystem
A self-organizing ecosystem composed of species and their interactions that differ from those that prevailed historically, resulting from human influence.
novel entities
One of 9 planetary boundaries which includes includes synthetic chemicals, plastics, radioactive materials, and interventions such as genetically modified organisms.
off-gassing
The emission of volatile organic compounds from synthetic and natural products.
offset
A voluntary payment made to reduce pollution or emissions at one location in order to compensate for an equal quantity of pollution or emissions at another location.
oil shale
Underground formation of fine-grained sedimentary rock that contains kerogen, a waxy hydrocarbon that can be converted to a heavy oil called shale oil when heated.
open graded
Aggregate all of which is within the same size range.
organic agriculture
The general method of growing crops using environmentally healthy methods and without using synthetic fertilizers or pesticides; also known as organic farming.
overconsumption
The act of consuming something in excess of its ability to be renewed.
overshoot
The gap between the demand for ecosystem services and the rate at which nature can provide them, that is, the amount by which resource consumption and waste production exceed nature’s capacity to create new resources and absorb waste.
paradigm
A fundamental framework for understanding the world; a coherent set of assumptions and concepts that defines a way of viewing reality.
particulate material
Matter in the form of fine solid particles or liquid droplets small enough to be suspended in air or water.
passive solar heating
Methods for using sunlight for heating without the use of active mechanical devices such as pumps or fans.
passive ventilation
Methods for using air movement for cooling without the use of active mechanical devices such as pumps or fans.
PassivHaus
A European design standard for energy-efficient buildings that use passive heating and cooling methods.
patch see habitat patch
peak oil
The point at which oil reaches its highest production levels, after which the rate of production declines.
peat
Partially decomposed plant material that has accumulated in a water-saturated anaerobic environment.
peer review
The process in which writing or research work is evaluated by outside experts in a relevant field to determine whether the work is of high enough quality to publish.
permaculture
A design strategy for agriculture and human communities based on observing patterns in nature; the word was coined by combining the words “permanent” and “agriculture.”
persistence
The property of a substance which lasts a long time without changing.
persistent organic pollutant
A class of organic chemicals that remain unchanged for long periods of time, accumulate in the food chain, and are toxic to humans and other animals.
pesticide
A synthetic substance designed to kill unwanted organisms; categories of pesticides include insecticides, rodenticides, herbicides, and fungicides.
petroleum
One of the three types of fossil fuel; also known as oil.
pH
A scale which indicates the degree of acidity or alkalinity, based on a measure of the concentration of hydrogen ions in water.
phantom power
Energy consumed by electronic devices when they are turned off or in standby mode.
photovoltaic cell
A semiconductor device which converts solar energy directly to electricity.
phytoremediation
The use of plants to treat pollutants.
pioneer
A species that colonizes a site in the earliest stages of succession.
place-based learning
An approach to learning in which curriculum is based on local knowledge.
point source
A source of pollution that comes from a single, identifiable source.
pollution
The accumulation of substances with adverse effects on the health of living organisms.
pollution prevention
The design of a process or activity to reduce or eliminate the creation of pollution or waste at the source.
polycrisis
An emergent phenomenon of multiple crises interacting in a complex system.
population
A group of individuals of one species living within a particular area.
population ecology
The study of the growth, decline, and changes in populations of organisms.
potable water
Water which is suitable for drinking.
power grid see grid
power
The rate at which energy is transferred.
ppb
Parts per billion; the number of parts of a chemical found in one billion parts of a particular gas, liquid, or solid mixture.
ppm
Parts per million; the number of parts of a chemical found in one million parts of a particular gas, liquid, or solid mixture.
precautionary principle
An approach to making decisions in a way that leaves a margin of safety because of the possibility of causing unexpected harm.
preservation
Efforts to maintain an area in a state that is relatively undisturbed by humans.
proxy
An indicator which stands in for another measurement.
quad
One quadrillion Btus.
radioactivity
The emission of atomic particles as atomic nuclei decay.
rain garden
A planted depression in the landscape where stormwater runoff collects temporarily as it infiltrates into the soil below.
rainwater endowment
The amount of rainwater which can be captured on a particular site.
rainwater harvesting
The process of collecting water that falls as rain and storing it for later use.
rammed earth
A construction method in which soil is laid in formwork and compacted in layers.
reclamation
The process of restoring a degraded site to an ecologically healthy state.
reconciliation ecology
An approach to restoration that deliberately shares the places where humans live with other species.
recycling
A waste disposal method which extracts materials from the waste stream and processes them so that they can be reused in some way.
remanufacturing
The process of repairing or rebuilding products or parts in order to use them again with the same function.
remediation
The process of cleaning up a polluted site using physical, chemical or biological means.
renewable energy certificate (REC)
A tradable commodity that represents a unit of electricity generated from a renewable energy source; also known as renewable energy credits, green certificates, or green tags.
renewable resource
A resource that is replenished by natural processes and not depleted by moderate use.
replacement fertility rate
The number of births per woman that will maintain the human population size constant at zero population growth.
reserve
The total known amount of an economically recoverable resource.
reservoir
A location where energy or matter are stored in systems.
residence time
The average amount of time that a substance spends in a particular reservoir.
resilience
The capacity of a system to accommodate change and still retain the same function and structure.
resource
The total quantity of a material that exists in the Earth’s crust, whether or not it has been discovered.
restoration see ecological restoration
restoration ecology
A scientific discipline that focuses on the recovery of degraded biodiversity and ecosystem function.
rhizosphere
The area of soil immediately around plant roots
riparian
Relating to or inhabiting the banks of a stream or river.
risk
The probability of an adverse consequence.
R-value
A measure of a material’s resistance to heat flow.
saltwater intrusion
The movement of saltwater into freshwater aquifers.
sanitary landfill
A landfill engineered to prevent leaks from contaminating soil and water.
scientific method
A systematic study of a problem in which scientists, collectively and over time, observe and describe a phenomenon, develop a hypothesis, collect data, and use the data to evaluate the hypothesis.
seed sovereignty
The right of people to breed and exchange seeds which can be saved, from which new plants can be grown, and which are not patented, genetically modified, owned, or controlled by corporate entities.
semiconductor
A material that conducts electric current under some conditions and whose electrical properties can be manipulated.
sequestration
The removal and storage of an element such as carbon in a sink through biological or physical processes.
service learning
Learning by doing while working on solutions to community problems.
servicizing
An invented word which refers to the practice of providing a service instead of a product.
shale oil
A slow-flowing, heavy oil produced when kerogen in oil shale is heated; subsequently refined to produce gasoline and other petroleum products.
silo
An insulated, vertical unit within an organization with little outside exchange of information.
sink
A reservoir where matter is stored and removed from system interactions.
smart grid
A networked microgrid that uses two-way meters, intelligent controls, telecommunications, and distributed storage to distribute electricity.
smart growth
An approach to urban planning which features compact, walkable, and transit-oriented neighborhoods with a mix of uses, housing types, and affordability levels.
smog
Air pollution formed by the interaction of pollutants and sunlight.
social capital
The capacity of a society to act in a cohesive way, built upon its cultural institutions and relationships.
social justice see equity
social marketing
The application of marketing principles to support social change.
soil horizon
One layer of soil in a soil profile.
soil profile
The pattern of soil layers in a particular place from the surface toward the bedrock below.
solar cell see photovoltaic cell
source
A storage compartment in the environment that releases matter to another location.
sparging
The injection of air directly into groundwater to increase oxygen available to bacteria.
sprawl
A human settlement pattern characterized by low-density land use, single-use zoning, and automobile dependency.
stakeholder
A person or group who can be impacted by an outcome or decision.
steady state
The condition in which inputs and outputs of a system are in equilibrium.
stewardship
Responsible care of the natural world. Also, the belief that humans have a unique responsibility to make decisions about the use and management of natural resources.
Stockholm Convention
An international treaty signed in 2001 which limits or eliminates the production of persistent organic pollutants.
stormwater
Water that falls as rain.
strong sustainability
An approach to economics which says that human and natural capital are not interchangeable and that natural capital is the limiting factor.
structural
A regulatory and policy-based approach to sustainability solutions, in contrast to an individual approach.
structural diversity
Variation in the vertical and horizontal features of a landscape.
submetering
The practice of using additional meters provided by building owners to record energy use in selected portions of a facility.
succession
Progressive change in species composition, structure, and ecosystem characteristics in a community, often in response to a disturbance,
Superfund
The program mandated by CERCLA and operated by the EPA for remediation of particularly polluted sites.
sustainability indicator see indicator
sustainability
The state in which the needs of all members of the biosphere are met without compromising the ability of future generations to meet their needs.
sustainability science
An interdisciplinary field of study of the interactions between natural, social, and human systems and with how those interactions impact sustainable development.
sustainable development
Development that meets the needs of the present generation without compromising the ability of future generations to meet their own needs.
sustainable
A method of using resources or meeting needs in such a way that we can continue to do so indefinitely.
swale
A linear drainage channel with a vegetated surface. See also bioswale.
symbiosis
A relationship between two organisms from different species who live with and interact with each other, benefiting both of them.
system
An integrated whole made of interconnected parts.
systems thinking
A way of perceiving reality which considers relationships, processes, and interconnected parts of unified wholes.
take-back program
A practice in which manufacturers assume responsibility for reusing or recycling the products which they produced.
tar sand
A naturally occurring deposit of sand impregnated with bitumen, a heavy oil that is extracted by heating; subsequently refined to produce petroleum products.
teratogen
A substance which causes abnormalities in developing embryos.
theory
An explanation of a phenomenon that has been rigorously tested and become accepted by a general consensus of scientists.
thermal mass
A heavy, dense building material which absorbs heat, stores it, and reradiates it slowly.
thermal pollution
An unhealthy change in water temperature.
thermodynamics
A branch of physics that deals with the transformation of energy.
threatened species
A species considered to be likely to become endangered in the near future.
throughput
The amount of materials and energy that flow through a system.
tipping point
The critical transition at which accumulated small changes a cause a system to shift abruptly and irreversibly into a new state.
total fertility rate
The number of children born to an average woman during her lifetime.
total suspended solids
Fine particles suspended in water, too small to be removed by settling.
toxicant
A substance that is harmful to living organisms.
toxicity
The degree to which a substance can damage living cells.
toxin
A toxicant produced by a living organism.
Traditional Ecological Knowledge (TEK)
The cumulative body of knowledge about the natural world acquired by Indigenous and local people over time through direct experience.
tragedy of the commons
The degradation of a public resource, the accumulated result of decisions by multiple self-interested individuals to maximize their own personal interests.
transformation
A change in the fundamental attributes of a system.
transition
The process of moving to a different state or condition in incremental steps.
transit-oriented development (TOD)
An element of smart growth in which neighborhood development is clustered around convenient transit stations and located along transit corridors.
transport
The ways in which a pollutant moves through the environment.
transportation demand management (TDM)
A set of tools and strategies for changing travel behavior in order to reduce the number of automobile vehicle trips and vehicle miles driven.
triatomic
A molecule composed of three atoms.
triple bottom line
The concept that sustainability rests upon the three pillars of environment, economics, and equity, also known as planet, people, profit.
trophic level
The position a group of organisms with similar feeding function occupies in a food web.
turbidity
A measure of water clarity resulting from suspended particles which block light.
urban heat island effect
The phenomenon in which air temperature in cities is several degrees warmer than in surrounding rural areas.
U-value
A measure of a material’s ability to conduct heat; the reciprocal of R-value.
virtual water
The quantity of water required for the production of food or other goods, measured at the place where they were actually produced.
volatile organic compounds (VOCs)
Organic compounds that vaporize at room temperature.
waste
Unwanted or discarded material.
waste-to-energy
A process which captures methane from landfills and burns it in gas turbines to generate electricity or heat.
water footprint
The virtual water content of a good or service.
water service company (WASCO)
A company which provides water auditing and conservation services for a building and whose fees are paid for out of water-use savings.
water table
The upper boundary of the zone of saturation, or groundwater.
watershed
An area of land that drains water to a specific river system or water body.
weak sustainability
An approach to economics which says that human-made capital can be substituted for natural capital.
wetland delineation
The process of identifying the location and size of a wetland for the purposes of meeting regulations.
wetland
An area of land that is periodically saturated with water and characterized by vegetation adapted for life in saturated-soil conditions.
wicked problems
Problems that are difficult to solve because they are complex, interconnected, and continually evolving.
xenobiotic
A synthetic chemical substance which is foreign to living systems.
No entries.
zero waste
An approach in which every material is a resource and waste does not build up.