This is a glossary of environmental science. Environmental science is the study of interactions among physical, chemical, and biological components of the environment. Environmental science provides an integrated, quantitative, and interdisciplinary approach to the study of environmental systems.
0-9 1-in-100 flood – a flood with 1 in 100 chance of occurring in any given year (used as a safety requirement for the construction industry.) 20/30/10 standard - 20 mg/L Biochemical Oxygen Demand (BOD), 30 mg/L Suspended Solids (SS), 10 units of E. coli: the water quality standard for greywater use in toilets, laundry and surface irrigation. 5Rs - (sustainability) reduce, remanufacture, reuse, recycle, recover.
A abiotic component - Any non-living chemical or physical part of the environment that affects living organisms and the functioning of ecosystems, such as the atmosphere and water resources. (see also biotic). absorption pit (soakaway) – a hole dug in permeable ground and filled with broken stones or granular material and usually covered with earth allowing collected water to soak into the ground. absorption - one substance taking in another, either physically or chemically. acclimation - the process of an organism adjusting to chronic change in its environment. acid mine drainage - the outflow of acidic water from metal mines or coal mines. acid rain - rain or other forms of precipitation that is unusually acidic. adaptation - a characteristic of an organism that has been favoured by natural selection. adaptive radiation - closely related species that look very different, as a result of having adapted to widely different ecological niches. additionality - (of biodiversity offsets) where the conservation outcomes delivered by a biodiversity offset are demonstrably new and would not have resulted without the offset. adsorption - one substance taking up another at its surface. aerobic - requiring air or oxygen; used in reference to decomposition processes that occur in the presence of oxygen. aerosols - solid or liquid particles suspended within the atmosphere. affluenza - as defined in the book of the same name 1. the bloated, sluggish and unfulfilled feeling that results from efforts to keep up with the Joneses. 2. an epidemic of stress, overwork, waste and indebtedness caused by dogged pursuit of the Australian dream. 3. an unsustainable addiction to economic growth. The traditional Western environmentally unfriendly high consumption life-style: a play on the words affluence and influenza cf. froogle, freegan. afforestation - planting new forests on lands that have not been recently forested. agroforestry - (sustainability) an ecologically based farming system, that, through the integration of trees in farms, increases social, environmental and economic benefits to land users. air pollution - the modification of the natural characteristics of the atmosphere by a chemical, particulate matter, or biological agent. albedo - reflectance; the ratio of light from the Sun that is reflected by the Earth's surface, to the light received by it. Unreflected light is converted to infrared radiation (heat), which causes atmospheric warming (see "radiative forcing"). Thus, surfaces with a high albedo, like snow and ice, generally contribute to cooling, whereas surfaces with a low albedo, like forests, generally contribute to warming. Changes in land use that significantly alter the characteristics of land surfaces can alter the albedo. algal bloom - the rapid and excessive growth of algae; generally caused by high nutrient levels combined with other favourable conditions. Blooms can deoxygenate the water leading to the loss of wildlife. alien species - see introduced species. alloy - composite blend of materials made under special conditions. Metal alloys like brass and bronze are well known but there are also many plastic alloys. alternative fuels - fuels like ethanol and compressed natural gas that produce fewer emissions than the traditional fossil fuels. anaerobic digestion - the biological degradation of organic materials in the absence of oxygen to yield methane gas (that may be combusted to produce energy) and stabilised organic residues (that may be used as a soil additive). anaerobic - not requiring air or oxygen; used in reference to decomposition processes that occur in the absence of oxygen. ancient forest - see old growth forest. anoxic - with abnormally low levels of oxygen. anthropogenic - man-made, not natural. anthroposophy - spiritual philosophy based on the teachings of Rudolf Steiner (25 February 1861 – 30 March 1925) which postulates the existence of an objective, intellectually comprehensible spiritual world accessible to direct experience through inner development - more specifically through cultivating conscientiously a form of thinking independent of sensory experience. Steiner was the initiator of biodynamic gardening. application efficiency - (sustainability) the efficiency of watering after losses due to runoff, leaching, evaporation, wind etc. appropriated carrying capacity - another name for the Ecological Footprint, but often used in referring to the imported ecological capacity of goods from overseas. aquaculture - the cultivation of aquatic organisms under controlled conditions. aquifer – a bed or layer yielding water for wells and springs etc.; an underground geological formation capable of receiving, storing and transmitting large quantities of water. Aquifer types include: confined (sealed and possibly containing “fossil” water); unconfined (capable of receiving inflow); and Artesian (an aquifer in which the hydraulic pressure will cause the water to rise above the upper confining layer). arable land - land that can be used for growing crops. atmosphere – general name for the layer of gases around a material body; the Earth's atmosphere consists, from the ground up, of the troposphere (which includes the planetary boundary layer or peplosphere, the lowest layer), stratosphere, mesosphere, ionosphere (or thermosphere), exosphere and magnetosphere. autotroph - an organism that produces complex organic compounds from simple inorganic molecules using energy from light or inorganic chemical reactions. available water capacity – that proportion of soil water that can be readily absorbed by plant roots. avoidance – (sustainability) the first step in the waste hierarchy where waste generation is prevented (avoided).
B backflow - movement of water back to source e.g. contaminated water in a plumbing system. baffle - (landscape design) an obstruction to trap debris in drainage water. bagasse - the fibrous residue of sugar cane milling used as a fuel to produce steam in sugar mills. baseload - the steady and reliable supply of energy through the grid. This is punctuated by bursts of higher demand known as “peak-load”. Supply companies must be able to respond instantly to extreme variation in demand and supply, especially during extreme conditions. Gas generators can react quickly while coal is slow but provides the steady "baseload". Renewable energies are generally not available on demand in this way. batters - (landscape design) the slope of earthworks such as drainage channels. best practice - a process, or innovative use of technology, equipment or resources or other measurable factors that have a proven record of success. bioaccumulation - the accumulation of a substance, such as a toxic chemical, in the tissues of a living organism. biocapacity - a measure of the biological productivity of an area. This may depend on natural conditions or human inputs like farming and forestry practices; the area needed to support the consumption of a defined population. biocoenosis (alternatively, biocoenose or biocenose ) – all the interacting organisms living together in a specific habitat (or biotope). biodegradable - capable of being decomposed through the action of organisms, especially bacteria. biodiversity - the variety of life in all its forms, levels and combinations; includes ecosystem diversity, species diversity, and genetic diversity. biodiversity banking - a market system for biodiversity offsetting that turns offsets into assets that can be traded. biodiversity credit - a certificate that represents a measured and evidence-based unit of positive biodiversity outcome that is durable and additional to what would otherwise have occurred. biodiversity offset - measurable conservation outcomes that result from actions designed to compensate for significant residual impacts on biodiversity, arising from a project and persisting after appropriate avoidance, minimization and restoration measures have been taken. The goal of biodiversity offsets is to achieve "no net loss" while adhering to a "like- for-like" principle, where offsets conserve the same biodiversity values that a project impacts. bioelement - an element required by a living organism. bioenergy - used in different senses: in its most narrow sense it is a synonym for biofuel, fuel derived from biological sources. In its broader sense it encompasses also biomass, the biological material used as a biofuel, as well as the social, economic, scientific and technical fields associated with using biological sources for energy. biofuel - the fuel produced by the chemical and/or biological processing of biomass. Biofuel will either be a solid (e.g. charcoal), liquid (e.g. ethanol) or gas (e.g. methane). biogas - landfill gas and sewage gas, also called biomass gas. biogeochemical cycle - a circuit or pathway by which a chemical element or molecule moves through both biotic ("bio-") and abiotic ("geo-") parts of an ecosystem. biogeochemical cycles - the movement of chemical elements between organisms and non-living components of the atmosphere, aquatic systems and soils. biological oxygen demand (BOD) - a chemical procedure for determining how fast biological organisms use up oxygen in a body of water. biological pest control - a method of controlling pests (including insects, mites, weeds and plant diseases) that relies on predation, parasitism, herbivory, or other natural mechanisms. biological productivity - (bioproductivity) the capacity of a given area to produce biomass; different ecosystems (i.e. pasture, forest, etc.) will have different levels of bioproductivity. Biological productivity is determined by dividing the total biological production (how much is grown and living) by the total area available. biologically productive land - is land that is fertile enough to support forests, agriculture and / or animal life. All of the biologically productive land of a country comprises its biological capacity. Arable land is typically the most productive area. biomass - the materials derived from photosynthesis (fossilised materials may or may not be included) such as forest, agricultural crops, wood and wood wastes, animal wastes, livestock operation residues, aquatic plants, and municipal and industrial wastes; the quantity of organic material present in unit area at a particular time mostly expressed as tons of dry matter per unit area; organic matter that can be used as fuel. biome - a climatic and geographically defined area of ecologically similar communities of plants, animals, and soil organisms, often referred to as ecosystems. biophysical - the living and non-living components and processes of the ecosphere. Biophysical measurements of nature quantify the ecosphere in physical units such as cubic metres, kilograms or joules. bioregion - (ecoregion) an area comprising a natural ecological community and bounded by natural borders. bioremediation - a process using organisms to remove or neutralise contaminants (e.g. petrol), mostly in soil or water. biosolids - nutrient-rich organic materials derived from wastewater solids (sewage sludge) that have been stabilised through processing. biosphere - the part of the Earth, including air, land, surface rocks, and water, within which life occurs, and which biotic processes in turn alter or transform. biosphere - the zone of air, land and water at the surface of the earth that is occupied by living organisms; the combination of all ecosystems on Earth and maintained by the energy of the Sun; the interface between the hydrosphere, geosphere and atmosphere. biotic potential - the maximum reproductive capacity of a population under optimum environmental conditions. biotic - relating to, produced by, or caused by living organisms. (see also abiotic). birth rate - number of people born as a percentage of the total population in any given period of time; number of live births per 1000 people. blackwater - household wastewater that contains solid waste i.e. toilet discharge. bluewater - collectible water from rainfall; the water that falls on roofs and hard surfaces usually flowing into rivers and the sea and recharging the ground water. In nature the global average proportion of total rainfall that is blue water is about 40%. Blue water productivity in the garden can be increased by improving irrigation techniques, soil water storage, moderating the climate, using garden design and water-conserving plantings; also safe use of grey water. boreal - northern; cold temperate Northern Hemisphere forests that grow where there is a mean annual temperature < 0 °C. broad-acre farm - commercial farm covering a large area; usually a mixed farm in dryland conditions. brownfield - a term often used to describe land previously used for industrial or commercial purposes with known or suspected pollution including soil contamination due to hazardous waste. Brundtland Commission Report - a UN report, Our Common Future, published in 1987 and dealing with sustainable development and the policies required to achieve it, which the report characterizes as "development that meets the needs of the present without compromising the ability of future generations to meet their own needs."
C C3 & C4 plants – C4 plants comprise about 5% of all plants, are most abundant in hot and arid conditions, and include crops like sugar cane and soybeans. During photosynthesis they form molecules with 4-carbon atoms and saturate at the given level of CO2. C3 plants, the other 95%, photosynthesise to form 3 carbon molecules and increase photosynthesis with as CO2 levels increase. calorie – a basic measure of energy that has been replaced by the SI unit the joule; in physics it approximates the energy needed to increase the temperature of 1 gram of water by 1 °C which is about 4.184 joules. The Calories in food ratings (spelled with a capital C) and nutrition are ‘big C’ Calories or kcal. calorific value – the energy content of a fuel measured as the heat released on complete combustion. cancer – a group of diseases in which cells are aggressive (grow and divide without respect to normal limits), invasive (invade and destroy adjacent tissues), and sometimes metastatic (spread to other locations in the body). capillary action (wicking) – water drawn through a medium by surface tension. car pooling – giving people lifts to help reduce emissions and traffic. carbon budget – a measure of carbon inputs and outputs for a particular activity. carbon credit – a market-driven way of reducing the impact of greenhouse gas emissions; it allows an agent to benefit financially from an emission reduction. There are two forms of carbon credit, those that are part of national and international trade and those that are purchased by individuals. Internationally, to achieve Kyoto Protocol objectives, ‘caps’ (limits) on participating country's emissions are established. To meet these limits countries, in turn, set ‘caps’ (allowances or credits: 1 convertible and transferable credit = 1 tonne of CO2-e emissions) for operators. Operators that meet the agreed ‘caps’ can then sell unused credits to operators who exceed ‘caps’. Operators can then choose the most cost-effective way of reducing emissions. Individual carbon credits would operate in a similar way cf. carbon offset. carbon cycle – the biogeochemical cycle by which carbon is exchanged between the biosphere, geosphere, hydrosphere, and atmosphere of the Earth. Carbon Dioxide Equivalent (CO2e ) – the unit used to measure the impacts of releasing (or avoiding the release of) the seven different greenhouse gases; it is obtained by multiplying the mass of the greenhouse gas by its global warming potential. For example, this would be 21 for methane and 310 for nitrous oxide. carbon dioxide – a gas with the chemical formula CO2; the most abundant greenhouse gas emitted from fossil fuels. carbon equivalent (C-e) – obtained by multiplying the CO2-e by the factor 12/44. carbon footprint – a measure of the carbon emissions that are emitted over the full life cycle of a product or service and usually expressed as grams of CO2-e. carbon labelling – use of product labels that display greenhouse emissions associated with goods (www.carbontrustcertification.com for product carbon footprint methodology). carbon neutral – activities where net carbon inputs and outputs are the same. For example, assuming a constant amount of vegetation on the planet, burning wood will add carbon to the atmosphere in the short term but this carbon will cycle back into new plant growth. carbon pool – a storage reservoir of carbon. carbon sink – any carbon storage system that causes a net removal of greenhouse gases from the atmosphere. carbon source – opposite of carbon sink; a net source of carbon for the atmosphere. carbon stocks – the quantity of carbon held within a carbon pool at a specified time. carbon taxes – a surcharge on fossil fuels that aims to reduce carbon dioxide emissions. carcinogen – a substance, radionuclide or radiation that is an agent directly involved in the promotion of cancer or in the facilitation of its propagation. carrying capacity – the maximum population that an ecosystem can sustain cf. biocapacity. catchment area – the area that is the source of water for a water supply whether a dam or rainwater tank. cell – (biology) the structural and functional unit of all known living organisms and is the smallest unit of an organism that is classified as living CFC – chlorofluorocarbon. CFCs are potent greenhouse gases which are not regulated by the Kyoto Protocol since they are covered by the Montreal Protocol. chlorinated hydrocarbon – see organochloride chlorofluorocarbons – one of the more widely known family of haloalkanes. circular metabolism – a system in which wastes, especially water and materials, are reused and recycled cf. linear metabolism. Class A pan – (water management) an open pan used as a standard for measuring water evaporation. cleaner production – the continual effort to prevent pollution, reduce the use of energy, water and material resources and minimise waste – all without reducing production capacity. clearcutting – a forestry or logging practice in which most or all trees in a forest sector are felled. climate change – a change in weather over time and/or region; usually relating to changes in temperature, wind patterns and rainfall; although may be natural or anthropogenic, common discourse carries the assumption that recent climate change is anthropogenic. climate – the general variations of weather in a region over long periods of time; the "average weather" cf. weather. cogeneration – the simultaneous production of electricity and useful heat from the combustion of the same fuel source. cohousing – clusters of houses having shared dining halls and other spaces, encouraging stronger social ties while reducing the material and energy needs of the community. coir – fibre of the coconut. commercial and industrial waste – (waste management) solid waste generated by the business sector as well as that created by State and Federal government, schools and tertiary institutions. Does not include that from the construction and demolition industry. commingled materials – (waste management) materials mixed together, such as plastic bottles, glass, and metal containers. Commingled recyclable materials require sorting after collection before they can be recycled. comparative risk assessment – a methodology which uses science, policy, economic analysis and stakeholder participation to identify and address areas of greatest environmental risk; a method for assessing environmental management priorities. The US EPA (www.epa.gov/seahome/comprisk.html) offers free software which contains the history and methodology of comparative risk, as well as many case studies. compensation point – the point where the amount of energy produced by photosynthesis equals the amount of energy released by respiration. Complex system is a system composed of many components which may interact with each other. compost – the aerobically decomposed remnants of organic matter. composting – the biological decomposition of organic materials in the presence of oxygen that yields carbon dioxide, heat, and stabilised organic residues that may be used as a soil additive. confined aquifer – aquifers that have the water table above their upper boundary and are typically found below unconfined aquifers. conspicuous consumption – the lavish spending on goods and services that are acquired mainly for the purpose of displaying income or wealth rather than to satisfy basic needs of the consumer. construction and demolition waste – (waste management) includes waste from residential, civil, and commercial construction and demolition activities, such as fill material (e.g. soil), asphalt, bricks and timber. C&D waste excludes construction waste which is included in the municipal waste stream. C&D waste does not generally include waste from the commercial and industrial waste stream. consumer democracy – using your economic capacity to promote your values. consumer – organism, human being, or industry that maintains itself by transforming a high-quality energy source into a lower one cf. Producer, primary production. consumption (ecology) – the use of resources by a living system, the inflow and degradation of energy that is used for system activity. consumption (economics) – part of disposable income (income after taxes paid and payments received) that is not saved, essentially the goods and services used by households; this includes purchased commodities at the household level (such as food, clothing, and utilities), the goods and services paid for by government (such as defence, education, social services and health care), and the resources consumed by businesses to increase their assets (such as business equipment and housing). contour ploughing (contour farming) – the farming practice of plowing across a slope following its contours. The rows formed have the effect of slowing water run-off during rainstorms so that the soil is not washed away and allows the water to percolate into the soil. controlled burning – a technique sometimes used in forest management, farming, prairie restoration or greenhouse gas abatement. Convention on the International Trade in Endangered Species (CITES) – International agreement among 167 governments aiming to ensure that cross-border trade in wild animals and plants does not threaten their survival. The species covered by CITES are listed in three Appendices, according to the degree of protection they need (see: http://www.cites.org) Corporate Social Responsibility – integration of social and environmental policies into day-to-day corporate business. covenants – formal agreements or contracts, often between government and industry sectors. The national packaging covenant and sustainability covenants are examples of voluntary covenants with a regulatory underpinning. Land covenants protect land for wildlife into the future. critical load – a concept in pollution studies hypothesizing that there exist quantitative thresholds for one or more pollutants above which significant detrimental effects on ecological systems (e.g. the eutrophication of natural waterways) will occur, and/or conversely below which they are not known to occur. crop coefficient (Kc) – (water management) a variable used to calculate the evapotranspiration of a plant crop based on that of a reference crop. crop evapotranspiration (ETc) – (water management) is the crop water use – the daily water withdrawal. crop rotation (crop sequencing) – the practice of growing a series of dissimilar types of crops in the same space in sequential seasons for various benefits such as to avoid the buildup of pathogens and pests that often occurs when one species is continuously cropped. crude oil – naturally occurring mixture of hydrocarbons under normal temperature and pressure. cullet – crushed glass that is suitable for recycling by glass manufacturers. cultural eutrophication - the process that speeds up natural eutrophication because of human activity. cultural services – the non-material benefits of ecosystems including refreshment, spiritual enrichment, knowledge, artistic satisfaction. culture jamming – altering existing mass media to criticise itself (e.g. defacing advertisements with an alternative message). Public activism opposing commercialism as little more than propaganda for established interests, and the attempt to find alternative expression. culvert – drain that passes under a road or pathway, may be a pipe or other conduit. cut and fill – removing earth from one place to another, usually mechanically. cyanobacteria (Cyanophyta or blue-green algae) – a phylum of bacteria that obtain their energy through photosynthesis. cyclone – intense low pressure weather systems; mid-latitude cyclones are atmospheric circulations that rotate clockwise in the Southern Hemisphere and anti-clockwise in the Northern Hemisphere and are generally associated with stronger winds, unsettled conditions, cloudiness and rainfall. Tropical cyclones (which are called hurricanes in the Northern Hemisphere) cause storm surges in coastal areas.
D DDT - a chlorinated hydrocarbon used as a pesticide that is a persistent organic pollutant. debt-for-Nature Swap - a financial transaction in which a portion of a developing nation's foreign debt is forgiven in exchange for local investments in conservation measures. decomposers – consumers, mostly microbial, that change dead organic matter into minerals and heat. deforestation - the conversion of forested areas to non-forest land for agriculture, urban use, development, or wasteland. dematerialisation – decreasing the consumption of materials and resources while maintaining quality of life. desalination producing potable or recyclable water by removing salts from salty or brackish water. This is done by three methods: distillation/freezing; reverse osmosis using membranes and electrodialysis; ion exchange. At present, all these methods are energy intensive. desert – an area that receives an average annual precipitation of less than 250 mm (9.8 in) or an area in which more water is lost than falls as precipitation. desertification - the degradation of land in arid, semi arid and dry sub-humid areas resulting from various climatic variations, but primarily from human activities. detritivore (detritus feeder) - animals and plants that consume detritus (decomposing organic material), and in doing so contribute to decomposition and the recycling of nutrients. detritus - non-living particulate organic material (as opposed to dissolved organic material). developing countries – development of a country is measured using a mix of economic factors (income per capita, GDP, degree of modern infrastructure (both physical and institutional), degree of industrialisation, proportion of economy devoted to agriculture and natural resource extraction) and social factors (life expectancy, the rate of literacy, poverty). The UN-produced Human Development Index (HDI) is a compound indicator of the above statistics. There is a strong correlation between low income and high population growth, both within and between countries. In developing countries, there is low per capita income, widespread poverty, and low capital formation. In developed countries there is continuous economic growth and a relatively high standard of living. The term is value-laden and prescriptive, as it implies a natural transition from "undeveloped" to "developed" when such transitions can instead be imposed. Although poverty and physical deprivation are clearly undesirable, it does not follow that it is therefore desirable for "undeveloped" economies to move towards affluent Western-style "developed" free market economies. The terms "industrialised" and "non-industrialised" are no different in this assumption. dfE – design for the environment; dfE considers 'cradle to grave' costs and benefits associated with material acquisition, manufacture, use, and disposal. dfM – design for manufacturing; designing products in such a way that they are easy to manufacture. dfS – design for sustainability; an integrated design approach aiming to achieve both environmental quality and economic efficiency through the redesign of industrial systems. dfX – design for assembly/disassembly, re-use. recycle. dieback – (arboriculture) a condition in trees or woody plants in which peripheral parts are killed, either by parasites or due to conditions such as acid rain. dietary energy supply – food available for human consumption, usually expressed in kilocalories per person per day. dioxin - any one of a number of chemical compounds that are persistent organic pollutants and are carcinogenic. distributed water – (water management) purchased water supplied to a user; this is usually through a reticulated mains system (but also through pipes and open channels, irrigation systems supplied to farms). diversion rate – (waste disposal) the proportion of a potentially recyclable material that has been diverted out of the waste disposal stream and therefore not directed to landfill. divertible resource – (water management) the proportion of water runoff and recharge that can be accessed for human use. downcycling – (waste management) recycling in which the quality of an item is diminished with each recycling. downstream – those processes occurring after a particular activity e.g. the transport of a manufactured product from a factory to the wholesale or retail outlet cf. upstream. drainage – (water management) that part of irrigation or rainfall that runs off an area or is lost to deep percolation. drawdown – (water management) drop in water level, generally applied to wells or bores. dredging - (water management) the repositioning of soil from an aquatic environment, using specialized equipment, in order to initiate infrastructural and/or ecological improvements. drift net - a type of fishing net used in oceans, coastal seas and freshwater lakes. drinking water – (potable water) – water fit for human consumption in accordance with World Health Organisation guidelines. drip irrigation – (water management) a drip hose placed near the plant roots so minimising deep percolation and evaporation. driver – (ecology) any natural or human-induced factor that directly or indirectly causes a change in an ecosystem. A direct driver is one that unequivocally influences ecosystem processes and that can be measured. drop-off centre – (waste management) a location where discarded materials can be left for recycling. drought – an acute water shortage relative to availability, supply and demand in a particular region. An extended period of months or years when a region notes a deficiency in its water supply. Generally, this occurs when a region receives consistently below average precipitation. dryland salinity - (water management) accumulation of salts in soils, soil water and ground water; may be natural or induced by land clearing
E eco- - a prefix now added to many words indicating a general consideration for the environment e.g. ecohousing, ecolabel, ecomaterial. eco-asset – a biological asset that provides financial value to private land owners when they are maintained in or restored to their natural state. ecolabel - seal or logo indicating a product has met a certain environmental or social standards. ecological deficit - of a country or region measures the amount by which its Ecological Footprint exceeds the ecological capacity of that region. Ecological Footprint (Eco-footprint, Footprint)– a measure of the area of biologically productive land and water needed to produce the resources and absorb the wastes of a population using the prevailing technology and resource management schemes; a measure of the consumption of renewable natural resources by a human population, be it that of a country, a region or the whole world given as the total area of productive land or sea required to produce all the crops, meat, seafood, wood and fibre it consumes, to sustain its energy consumption and to give space for its infrastructure. ecological niche - the habitat of a species or population within its ecosystem. ecological succession - the more-or-less predictable and orderly changes in the composition or structure of an ecological community with time. ecological sustainability - the capacity of ecosystems to maintain their essential processes and function and to retain their biological diversity without impoverishment. ecologically sustainable development - using, conserving and enhancing the human community's resources so that ecological processes, on which all life depends, can be maintained and enriched into the future. ecology - the scientific study of living organisms and their relationships to one another and their environment; the scientific study of the processes regulating the distribution and abundance of organisms; the study of the design of ecosystem structure and function. externality – a cost or benefit that are not borne by the producer or supplier of a good or service. In many environmental situations environmental deterioration may be caused by a few while the cost is borne by the community; examples would include overfishing, pollution (e.g. production of greenhouse emissions that are not compensated for in any way by taxes etc.), the environmental cost of land-clearing etc. ecoregion - (bioregion) the next smallest ecologically and geographically defined area beneath realm (or ecozone). ecosystem boundary – the spatial delimitation of an ecosystem usually based on discontinuities of organisms and the physical environment. ecosystem services - the role played by organisms, without charge, in creating a healthy environment for human beings, from production of oxygen to soil formation, maintenance of water quality and much more. These services are now generally divided into four groups, supporting, provisioning, regulating and cultural. ecosystem - a dynamic complex of plant, animal and microorganism communities and their non-living environment all interacting as a functional unit. e-cycling – recycling electronic waste. effective rainfall – the volume of rainfall passing into the soil; that part of rainfall available for plant use after runoff, leaching, evaporation and foliage interception. energy efficiency - using less energy to provide the same level of energy service. effluent - a discharge or emission of liquid, gas or other waste product. El Niño - a warm water current which periodically flows southwards along the coast of Ecuador and Peru in South America, replacing the usually cold northwards flowing current; occurs once every five to seven years, usually during the Christmas season (the name refers to the Christ child); the opposite phase of an El Niño is called a La Niña. embodied energy - the energy expended over the entire life cycle of a good or service cf. emergy. emergent property – a property that is not evident in the individual components of an object or system. emergy – “energy memory” all the available energy that was used in the work of making a product directly and indirectly, expressed in units of one type of available energy (work previously done to provide a product or service); the energy of one type required to make energy of another. emission standard - a level of emissions that, under law, may not be exceeded. emissions intensity – emissions expressed as quantity per monetary unit. emissions trading – see carbon trading. emissions - substances such as gases or particles discharged into the atmosphere as a result of natural processes of human activities, including those from chimneys, elevated point sources, and tailpipes of motor vehicles. endangered species – a species which is at risk of becoming extinct because it is either few in number, or threatened by changing environmental or predation parameters. energetics – the study of how energy flows within an ecosystem: the routes it takes, rates of flow, where it is stored and how it is used. energy - a property of all systems which can be turned into heat and measured in heat units. * available energy – energy with the potential to do work (exergy); * delivered energy – energy delivered to and used by a household, usually gas and electricity; * direct energy - the energy being currently used, used mostly at home (delivered energy) and for fuels used mainly for transport; * embodied energy - t the energy expended over the entire life cycle of a good or service OR the energy involved in the extraction of basic materials, processing/manufacture, transport and disposal of a product OR the energy required to provide a good or service; * geothermal energy – heat emitted from within the Earth's crust as hot water or steam and used to generate electricity after transformation; * hydro energy – potential and kinetic energy of water used to generate electricity; * indirect energy – the energy generated in, and accounted for, by the wider economy as a consequence of an agent's actions or demands; * kinetic energy - the energy possessed by a body because of its motion; * nuclear energy - energy released by reactions within atomic nuclei, as in nuclear fission or fusion (also called atomic energy); * operational energy – the energy used in carrying out a particular operation; * potential energy – the energy possessed by a body as a result of its position or condition e.g. coiled springs and charged batteries have potential energy; * primary energy – forms of energy obtained directly from nature, the energy in raw fuels (electricity from the grid is not primary energy), used mostly in energy statistics when compiling energy balances; * solar energy – solar radiation used for hot water production and electricity generation (does not include passive solar energy to heat and cool buildings etc.); * secondary energy – primary energies are transformed in energy conversion processes to more convenient secondary forms such as electrical energy and cleaner fuels; * stationary energy – that energy that is other than transport fuels and fugitive emissions, used mostly for production of electricity but also for manufacturing and processing and in agriculture, fisheries etc.; * tidal/ocean/wave energy– mechanical energy from water movement used to generate electricity; * useful energy – available energy used to increase system production and efficiency; * wind energy – kinetic energy of wind used for electricity generation using turbines energy accounting – measuring value by the energy input required for a good or service. A form of accounting that builds in a measure of our impact on nature (rather than being restricted to human-based items). energy audit - a systematic gathering and analysis of energy use information that can be used to determine energy efficiency improvements. The Australian and New Zealand Standard AS/NZS 3598:2000 Energy Audits defines three levels of audit. Energy Footprint - the area required to provide or absorb the waste from coal, oil, gas, fuelwood, nuclear energy and hydropower: the Fossil Fuel Footprint is the area required to sequester t