Glossary of Terms

This page contains definitions and explanations for some of the more frequently used words contained within the site.


A non living component of an ecosystem e.g. sunlight


Produced by human activity

Agenda 21

A framework of political recommendations designed to protect the environment and encourage nations to move towards achieving sustainable development in the 21st Century.

Available biological capacity

The quantity of biologically productive space available for human use.


The variety of life in all its forms, levels and combinations. Includes ecosystem, species and genetic diversity.

Biodiversity responsibility

The amount of biologically productive area a nation would need to set aside in order for global biodiversity to be maintained. A figure of 12% is generally accepted as the minimum requirement.


A fuel produced from dry organic matter or combustible oils produced by plants. Examples of biofuel include alcohol (from fermented sugar), bio diesel from vegetable oil and wood.

Biological capacity

The total annual biological production capacity of a given biologically productive area.

Biological productivity

A measurement of biological production of a given area over a given time period. A typical indicator of biological productivity is the annual biomass accumulation of an ecosystem.

Biologically productive area

The land and water area that is biologically productive.


The total mass of all living organisms within a biological community.


The part of the earth and its atmosphere in which living organisms exist or that is capable of supporting life.


The living components of an ecosystem.

Carbon dioxide

(CO2) A greenhouse gas produced through respiration and the decomposition of organic substances. Combustion of fossil fuels is primarily responsible for increased atmospheric concentrations of this gas.

Carbon footprint

A representation of the effect human activities have on the climate in terms of the total amount of greenhouse gases produced (measured in units of carbon dioxide).

Carbon sequestration

Refers to the process by which atmospheric carbon is absorbed in to carbon sinks such as the oceans, forests and soil.

Carrying capacity

The total population an area is able to support given the quality of the natural environment and the prevailing technology available.


All the goods and services used by households.

Ecological deficit

The amount by which the ecological footprint of a country or region exceeds the biological capacity of the space available

Ecological footprint

The area of land and water required to support a defined economy or human population at a specified standard of living indefinitely, using prevailing technology.


The system of interactions between living organisms and their environment.

Embodied energy

The energy used during the entire life cycle of a commodity i.e. manufacture, transportation and disposal.

Energy efficiency

The more efficient use of energy in order to reduce economic costs and environmental impacts. Using less energy/electricity to perform the same function.


Limited or restricted in nature.

Food Miles

The number of miles food produce travels from ‘plough to plate’, that is from the place of production to consumption.

Fossil fuel

A naturally occurring fuel rich in carbon and hydrogen formed by the decomposition of pre historic organisms. Fossil fuels include coal, natural gas and fuels made from crude oil such as petrol and diesel.

Fuel economy

The number of miles driven divided by the number of gallons consumed.

Global hectare

One hectare of biologically productive space adjusted to world average biomass productivity allowing meaningful comparisons across regions to be made.

Greenhouse gases

Those gases present in the atmosphere that trap heat from the sun and warm the earth. Such gases include carbon dioxide, methane, water vapour, nitrous oxide, ozone and halocarbons.


One hectare (Ha) is equivalent to 10, 000 square metres (100 x 100). This is approximately the same size as full size football pitch.


Essentially a cavity in the ground in to which refuse is disposed of. Once full this is covered over and landscaped so as to appear as part of the surrounding area.


A person's pattern of living as expressed in his or her activities, interests, and opinions.


Liquid Petroleum Gas.


(CH4) A colourless, odourless gas formed when organic matter anaerobically decomposes. Methane is about 20 times more effective than carbon dioxide as a greenhouse gas. Major sources include fermentation in ruminant animals, decay of organic material in rice paddies and landfill.

Non-renewable resource

A resource that is not replaced or only replaced very slowly by natural processes.


The point where human consumption and waste production exceed nature’s capacity to create new resources and absorb waste.

Per capita

For each person. Per head.


The process by which discarded materials are collected, sorted, processed and converted in to raw materials which are then used in the production of new products.

Renewable resource

A natural resource that can be replaced


A new or reserve supply that can be drawn upon when needed.

Sustainable Development

Has been defined as ‘Development which meets the needs of the present without compromising the ability of future generations to meet their own needs’.


Sustainability is effectively the goal of sustainable development. It is the ideal end state which we must aspire.


One metric ton is equal to 1000 kilograms, approximately the weight of a small family car.

Triple bottom line

An expanded baseline for measuring performance, adding social and environmental dimensions to the traditional monetary benchmark.