Glossary Of Environmental Science

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.

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 build up 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 the term used to describe 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 cause storm surges in coastal areas.


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 (10 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 rather value-laden and prescriptive as it implies a natural transition from ndeveloped to eveloped. Although poverty and physical deprivation are clearly undesirable, it does not follow that it is therefore desirable for ndeveloped economies to move towards affluent Western-style eveloped free market economies. We have tended to use the terms ndustrialised and on-industrialised although these too can be misleading.

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


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.

economic externalities costs or benefits 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 Nio - 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 Nio is called a La Nia.

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 nergy 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 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 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 the emitted CO2 taking into account CO2 absorption by the sea etc.

energy management - A program of well-planned actions aimed at reducing energy use, recurrent energy costs, and detrimental greenhouse gas emissions.

energy recovery the productive extraction of energy, usually electricity or heat, from waste or materials that would otherwise have gone to landfill.

energy-for-land ratio - the amount of energy that can be produced per hectare of ecologically productive land. The units used are gigajoules per hectare and year, or GJ/ha/yr. For fossil fuel (calculated as CO2 assimilation) the ratio is 100 GJ/ha/yr.

enhanced greenhouse effect - the increase in the natural greenhouse effect resulting from increases in atmospheric concentrations of greenhouse gases due to emissions from human activities.

ENSO (El Nioouthern Oscillation) a suite of events that occur at the time of an El Nio; at one extreme of the cycle, when the central Pacific Ocean is warm and the atmospheric pressure over Australia is relatively high, the ENSO causes drought conditions over eastern Australia cf. El Nio, Southern Oscillation.

environment - the external conditions, resources, stimuli etc. with which an organism interacts.

environmental flows - river or creek water flows that are allocated for the maintenance of the waterway ecosystems.

environmental indicator - physical, chemical, biological or socio-economic measure that can be used to assess natural resources and environmental quality.

environmental movement (environmentalism) - a term that sometimes includes the conservation and green movements; a diverse scientific, social, and political movement. In general terms, environmentalists advocate the sustainable management of resources and stewardship of the natural environment through changes in public policy and individual behavior. In its recognition of humanity as a participant in ecosystems, the movement is centered around ecology, health, and human rights.

environmental science - the study of interactions among physical, chemical, and biological components of the environment.

epidemiology - the study of factors affecting the health and illness of populations, and serves as the foundation and logic of interventions made in the interest of public health and preventive medicine.

erosion - displacement of solids (sediment, soil, rock and other particles) usually by the agents of currents such as, wind, water, or ice by downward or down-slope movement in response to gravity or by living organisms.

Escherichia coli (E. coli) a bacterium used as an indicator of faecal contamination and potential disease organisms in water.

estuary - a semi-enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea.

ethical consumerism - buying things that are made ethically i.e. without harm to or exploitation of humans, animals or the natural environment. This generally entails favoring products and businesses that take account of the greater good in their operations.

ethical living adopting lifestyles, consumption and shopping habits that minimise our negative impact, and maximise our positive impact on people, the environment and the economy cf. consumer democracy, sustainable living.

eutrophication - the enrichment of waterbodies with nutrients, primarily nitrogen and phosphorus, which stimulates the growth of aquatic organisms.

eutrophication - an increase in chemical nutrients, typically compounds containing nitrogen or phosphorus, in an ecosystem.

euxenic - with extremely low oxygen cf. anoxic.

evaporation water converted to water vapour.

evapotranspiration (ET) the water evaporating from the soil and transpired by plants.

e-waste - electronic waste, especially mobile phones, televisions and personal computers.

extended producer responsibility (EPR) (product take-back) - a requirement (often in law) that producers take back and accept responsibility for the responsible disposal of their products; this encourages the design of products that can be easily repaired, recycled, reused or upgraded.

external water footprint the embodied water of imported goods cf. internal water footprint.

externality (environmental economics) by-products of activities that affect the well-being of people or damage the environment, where those impacts are not reflected in market prices. The costs (or benefits) associated with externalities do not enter standard cost accounting schemes. The environment is often cited as a negatively affected externality of the economy (see economic externality).

extinction event - (mass extinction, extinction-level event, ELE) - a sharp decrease in the number of species in a relatively short period of time.

extinction - the cessation of existence of a species or group of taxa, reducing biodiversity.


feedback flow from the products of an action back to interact with the action.

feedlot (feedyard) - a type of Confined Animal Feeding Operation (CAFO) (also known as "factory farming") which is used for finishing livestock, notably beef cattle, prior to slaughter.

fertigate apply fertiliser through an irrigation system.

fertility rate - number of live births per 1,000 women aged 15 to 44 years cf. birth rate, mortality rate.

fertilizers (also spelled fertilisers) - compounds given to plants to promote growth; they are usually applied either through the soil, for uptake by plant roots, or by foliar feeding, for uptake through leaves.

flyway - the flight paths used in bird migration. Flyways generally span over continents and often oceans.

food chain (food webs, food networks and/or trophic networks) - describe the feeding relationships between species within an ecosystem.

food miles - the emissions produced and resources needed to transport food and drink around the globe.

food security - global food security refers to food produced in sufficient quantity to meet the full requirements of all people i.e. total global food supply equals the total global demand. For households it is the ability to purchase or produce the food they need for a healthy and active life (disposable income is a crucial issue). Women are typically gatekeepers of household food security. For national food security, the focus is on sufficient food for all people in a nation and it entails a combination of national production, imports and exports. Food security always has components of production, access and utilisation.

Footprint (Ecological Footprint) in a very general environmental sense a "footprint" is a measure of environmental impact. However, this is usually expressed as an area of productive land (the footprint) needed to counteract the impact.

forage - the plant material (mainly plant leaves) eaten by grazing animals.

forest land with a canopy cover greater than 30%.

fossil fuel - any hydrocarbon deposit that can be burned for heat or power, such as coal, oil and natural gas (produces carbon dioxide when burnt); fuels formed from once-living organisms that have become fossilized over geological time.

fossil water groundwater that has remained in an aquifer for thousands or millions of years; when geologic changes seal the aquifer preventing further replenishment, the water becomes trapped inside and is then referred to as fossil water. Fossil water is a limited resource and can only be used once.

freegan - a person using alternative strategies for living based on limited participation in the conventional economy and minimal consumption of resources. Freegans embrace community, generosity, social concern, freedom, cooperation, and sharing - in opposition to materialism, moral apathy, competition, conformity, and greed. The most notorious freegan strategy is "urban foraging" or "dumpster diving". This technique involves rummaging through the garbage of retailers, residences, offices, and other facilities for useful goods. The word freegan is compounded from "free" and "vegan". cf. affluenza, froogle.

freon - DuPont's trade name for its odourless, colorless, nonflammable, and noncorrosive chlorofluorocarbon and hydrochlorofluorocarbon refrigerants, which are used in air conditioning and refrigeration systems Fair trade - a guarantee that a fair price is paid to producers of goods or services; it includes a range of other social and environmental standards including safety standards and the right to form unions.

freshwater - water containing no significant amounts of salt; potable water suitable for all normal uses cf. potable water.

front (weather) the boundary between warm (high pressure) and cold (low pressure) air masses.

froogle - a play on the word frugal, referring to people who lead low-consumption life-styles: a person who is part of a new movement towards self-sufficiency and waste-reduction achieved by bartering goods and services especially through the internet, making their own products, soap, clothes, and breeding chickens and goats, growing their own food, baking their own bread, harvesting their own water and energy, and helping to develop a sense of community. Sometimes referring to people who have made a resolution to only buy essentials for a particular period of time cf. freegan, affluenza.

fugitive emissions - in the context of the National Greenhouse Gas Inventory, these are greenhouse gases emitted from fuel production itself including, processing, transmission, storage and distribution processes, and including emissions from oil and natural gas exploration, venting, and flaring, as well as the mining of black coal.

full-cost pricing - the pricing of commercial goodsuch as electric powerhat includes not only the private costs of inputs, but also the costs of the externalities required by their production and use cf. externality.


G8 - The Group of Eight is an international forum for the world's major industrialised democracies that emerged following the 1973 oil crisis and subsequent global recession. It includes Canada, France, Germany, Italy, Japan, Russia, the UK and the US which represents about 65% of the world economy.

Gaia hypothesis - an ecological hypothesis that proposes that living and nonliving parts of the earth are a complex interacting system that can be thought of as a single organism.

gene pool - the complete set of unique alleles in a species or population.

generalist species - those able to thrive in a wide variety of environmental conditions and can make use of a variety of different resources.

gene - a locatable region of genomic sequence, corresponding to a unit of inheritance, which is associated with regulatory regions, transcribed regions and/or other functional sequence regions.

genetic diversity - one of the three levels of biodiversity that refers to the total number of genetic characteristics.

greenhouse effect - the process in which the emission of infrared radiation by the atmosphere warms a planet's surface.

greenhouse gas - components of the atmosphere that contribute to the greenhouse effect.

green manure - a type of cover crop grown primarily to add nutrients and organic matter to the soil.

Green Revolution - the ongoing transformation of agriculture that led in some places to significant increases in agricultural production between the 1940s and 1960s.

groundwater - water located beneath the ground surface in soil pore spaces and in the fractures of lithologic formation.

garden organics - organics derived from garden sources e.g. prunings, grass clippings.

genetic engineering - general term covering the use of various experimental techniques to produce molecules of DNA containing new genes or novel combinations of genes, usually for insertion into a host cell for cloning; the technology of preparing recombinant DNA in vitro by cutting up DNA molecules and splicing together fragments from more than one organism; the modification of genetic material by man that would otherwise be subject to the forces of nature only.

genome the total genetic composition of an organism

geosphere - the solid part of planet Earth, the main divisions being the crust, mantle, and liquid core. The lithosphere is the part of the geosphere that consists of the crust and upper mantle.

geothermal energy - energy derived from the natural heat of the earth contained in hot rocks, hot water, hot brine or steam.

global acres see global hectares.

global dimming a reduction in the amount of direct solar radiation reaching the surface of the earth due to light diffusion as a result of air pollution and increasing levels of cloud. A phenomenon of the last 3050 years.

economic globalization - the emerging international economy characterized by free trade in goods and services, unrestricted capital flows and more limited national powers to control domestic economies.

global hectares - acres/hectares that have been adjusted according to world average biomass productivity so that they can be compared meaningfully across regions; 1 global hectare is 1 hectare of biologically productive space with world average productivity.

global warming potential - a system of multipliers devised to enable warming effects of different gases to be compared.

global warming the observable increase in global temperatures considered mainly caused by the human induced enhanced greenhouse effect trapping the Sun heat in the Earth atmosphere.

globalisation the expansion of interactions to a global or worldwide scale; the increasing interdependence, integration and interaction among people and organisations from around the world. A general term, used since the mid 1940s, referring to a mix of economic, social, technological, cultural and political interrelationships.

glyphosate the active ingredient in the herbicide RoundupTM.

governance refers to the decision-making procedure - who makes decisions, how they are made, and with what information: the structures and processes for collective decision-making involving governmental and non-governmental actors.

green architecture - building design that moves towards self-sufficiency sustainability by adopting circular metabolism.

green design - environmentally sustainable design.

green power - Electricity generated from clean, renewable energy sources (such as solar, wind, biomass and hydro power) and supplied through the grid.

green products and services - products or services that have a lesser or reduced effect on human health and the environment when compared with competing products or services that serve the same purpose. Green products or services may include, but are not limited to, those which contain recycled content, reduce waste, conserve energy or water, use less packaging, and reduce the amount of toxics disposed or consumed.

green purchasing - purchasing goods and services that minimise impacts on the environment and that are socially just.

Green Star a voluntary building rating for green design covering 9 impact categories up to 6 stars which equals world leader.

green waste (green organic material or green organics, sometimes referred to as reen wealth) - plant material discarded as non-putrescable waste - includess tree and shrub cuttings and prunings, grass clippings, leaves, natural (untreated) timber waste and weeds (noxious or otherwise).

green (sustainability) like co - a word frequently used to indicate consideration for the environment e.g. green plumbers, green purchasing etc., sometimes used as a noun e.g. the Greens.

greenhouse effect - the insulating effect of atmospheric greenhouse gases (e.g., water vapor, carbon dioxide, methane, etc.) that keeps the Earth's temperature about 60 F (16 C) warmer than it would be otherwise cf. enhanced greenhouse effect .

greenhouse gases - any gas that contributes to the greenhouse effect; gaseous constituents of the atmosphere, both natural and from human activity, that absorb and re-emit infrared radiation. Water vapor (H2O) is the most abundant greenhouse gas. Greenhouse gases are a natural part of the atmosphere and include carbon dioxide (CO2), methane (CH4, persisting 9-15 yrs with a greenhouse warming potential (GWP) 22 times that of CO2), nitrous oxide (N2O persists 120 years and has a GWP of 310), ozone (O3),hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride.

greenlash dramatic changes in the structure and dynamic behaviour of ecosystems.

greenwashing - a derogatory term used to describe companies that portray themselves as environmentally friendly when their business practices do not back this up. Generally applies to excessive use of green marketing and packaging when this does not take account of the total ecological footprint.

greenwater water replenishing soil moisture, evaporating from soil, plant and other surfaces, and transpired by plants. In nature the global average amount of rainfall becoming green water is about 60%. Of the green water about 55% falls on forests, 25% on grasslands and about 20% on crops. We can increase green water productivity by rainwater harvesting, increased infiltration and runoff collection. Green water cannot be piped or drunk (cannot be sold) and is therefore generally ignored by water management authorities but it is crucial to plants in both nature and agriculture and needs careful management as an important part of the global water cycle.

greywater household waste water that has not come into contact with toilet waste; includes water from baths, showers, bathrooms, washing machines, laundry and kitchen sinks.

gross primary productivity - total carbon assimilation.

groundwater water found below the surface usually in porous rocks, or soil, or in underground aquifers.

growth increase in size, weight, power etc.


habitat - an ecological or environmental area that is inhabited by a particular species.

hard waste - household garbage which is not normally accepted into rubbish bins by local councils, e.g. old stoves, mattresses.

heat energy derived from the motion of molecules; a form of energy into which all other forms of energy may be degraded .

herbicide a chemical the kills or inhibits growth of a plant.

herbivory - predation in which an organism known as an herbivore, consumes principally autotrophs such as plants, algae and photosynthesizing bacteria.

heterotroph (chemoorganotrophy) - an organism that requires organic substrates to obtain its carbon for growth and development.

hierarchy an organisation of parts in which control from the top (generally with few parts), proceeds through a series of levels (ranks) to the bottom (generally of many parts) cf. heterarchy.

high density polyethylene (HDPE) - A member of the polyethylene family of plastics and is used to make products such as milk bottles, pipes and shopping bags. HDPE may be coloured or opaque.

homoclime a region with the same climate as the one under investigation.

horsepower (hp) = 745.7 watts.

homeostasis - the property of either an open system or a closed system, especially a living organism, that regulates its internal environment so as to maintain a stable, constant condition.

Horton overland flow - the tendency of water to flow horizontally across land surfaces when rainfall has exceeded infiltration capacity and depression storage capacity.

house energy rating - an assessment of the energy efficiency of residential house or unit designs using a 5 star scale.

household metabolism - the passage of food, energy, water, goods, and waste through the household unit in a similar way to the metabolic activity of an organism cf. industrial metabolism.

humus - organic material in soil lending it a bark brown or black colouration.

human equivalent (He) - the approximate human daily energy requirement of 12,500 kJ or its approximate energy generating capacity at basal metabolic rate which is equivalent to about 80 watts (3.47222kWh/day). A 100 watt light bulb therefore runs at 1.25 He.

humus semi-persistent organic matter in the soil that can no longer be recognised as tissue.

hydrocarbons - chemicals made up of carbon and hydrogen that are found in raw materials such as petroleum, coal and natural gas, and derived products such as plastics.

hydroelectric power - the electrical power generated using the power of falling water.

hydrological cycle (water cycle) - the natural cycle of water from evaporation, transpiration in the atmosphere, condensation (rain and snow), and flows back to the ocean (e.g. rivers).

hydrosphere - all the Earth's water; this would include water found in the sea, streams, lakes and other waterbodies, the soil, groundwater, and in the air.


incineration - combustion (by chemical oxidation) of waste material to treat or dispose of that waste material.

indicator species - any biological species that defines a trait or characteristic of the environment.

industrial agriculture - a form of modern farming that refers to the industrialized production of livestock, poultry, fish, and crops.

Industrial Revolution - a period in the late 18th and early 19th centuries when major changes in agriculture, manufacturing, and transportation had a profound effect on socioeconomic and cultural conditions.

infiltration movement of water below topsoil to the plant roots and below.

infiltration - the process by which water on the ground surface enters the soil.

indicators quantitative markers for monitoring progress towards desired goals.

industrial ecology (term int. Harry Zvi Evan 1973) - the observation that nature produces no waste and therefore provides an example of sustainable waste management. Natural Capitalism espouses industrial ecology as one of its four pillars together with energy conservation, material conservation , and redefinition of commodity markets and product stewardship in terms of a service economy. Publications:

insecticide - a pesticide used to control insects in all developmental forms.

Integrated Pest Management (IPM) - a pest control strategy that uses an array of complementary methods: natural predators and parasites, pest-resistant varieties, cultural practices, biological controls, various physical techniques, and the strategic use of pesticides.

intercropping - the agricultural practice of cultivating two or more crops in the same space at the same time.

in-stream use - the use of freshwater where it occurs, usually within a river or stream: it includes hydroelectricity, recreation, tourism, scientific and cultural uses, ecosystem maintenance, and dilution of waste.

integrated pest management (IPM) pest management that attempts to minimise chemical use by using several pest control options in combination. The goal of IPM is not to eliminate all pests but to reduce pest populations to acceptable levels; an ecologically based pest control strategy that relies heavily on natural mortality factors and seeks out control tactics that disrupt these factors as little as possible.

integrated product life-cycle management - management of all phases of goods and services to be environmentally friendly and sustainable.

inter-generational equity the intention to leave the world in the best possible condition for future generations.

Intergovernmental Panel on Climate Change (IPCC) - the IPCC was established in 1988 by the World Meteorological Organization and the UN Environment Programme to provide the scientific and technical foundation for the United Nations Framework Convention on Climate Change (UNFCCC), primarily through the publication of periodic assessment reports.

internal water footprint the water embodied in goods produced within a country (although these may be subsequently exported) cf. external water footprint.

intrinsic value the value of something that is independent of its utility.

irrigation index an efficiency indicator showing degree of match between applied and used water. Ideal rating = 1, an Ii of 1.5 means an oversupply of water by 50%.

irrigation scheduling watering plants according to their needs.

irrigation watering of plants, no matter what system is used.

ISO 14001- The international standard for companies seeking to certify their environmental management system. International Organisation for Strandardisation (ISO) 14001 standard was first published in 1996 specifying the requirements for an environmental management system in organization (companies and institutions) with the goal of minimizing harmful effects on the environment and the goal of continual improvement of environmental performance.


joule (J) the basic unit of energy; the equivalent of 1 watt of power radiated or dissipated for 1 second. Natural gas consumption is usually measured in megajoules (MJ), where 1 MJ = 1, 000,000 J. On large accounts it may be measured in gigajoules (GJ), where 1 GJ = 1 000,000,000 J.


kerbside collection - collection of household recyclable materials (separated or co-mingled) that are left at the kerbside for collection by local council services .

keystone species - a species that has a disproportionate effect on its environment relative to its abundance, affecting many other organisms in an ecosystem and help in determine the types and numbers of various others species in a community.

Kyoto Protocol - an international agreement adopted in December 1997 in Kyoto, Japan. The Protocol sets binding emission targets for developed countries that would reduce their emissions on average 5.2 percent below 1990 levels.


land use, Land-use change and forestry (LULUCF) - land uses and land-use changes can act either as sinks or as emission sources. It is estimated that approximately one-fifth of global emissions result from LULUCF activities. The Kyoto Protocol allows parties to receive emissions credit for certain LULUCF activities that reduce net emissions.

landfill- solid waste disposal in which refuse is buried between layers of soil, a method often used to reclaim low-lying ground; the word is sometimes used as a noun to refer to the waste itself.

landfill gas the gas emissions from biodegrading waste in landfill, including CO2, CH4, and small amounts of nitrogen, oxygen...

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