7. Glossary


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acute exposure

Exposure to a chemical for 14 days or less.

aerobic respiration

Complex process that occurs in the cells of most living organisms in which nutrient organic molecules such as glucose, combine with oxygen and produce carbon dioxide, water and energy

air inversion

Air temperature increases rather than decreases with height. Temperature inversions arise naturally, but they make air pollution worse by reducing the amount of air in which the pollutants can mix

air pollution

Contamination of air with matter or energy to an undesirable level that may be detrimental to the health, safety or welfare of any living species

air quality

The condition of the air we breathe


A geographic area requiring unified management for achieving air pollution control

ambient air

Surrounding outdoor air

anaerobic respiration

A complex process that occurs in cells in the absence of oxygen


Australia and New Zealand Environment and Conservation Council

Arctic and glacier shrinkage

The floating ice sheets over the Arctic are shrinking. Almost every easily accessible glacier is retreating


The gaseous envelope surrounding the Earth

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Able to be broken down into simpler compounds by micro-organisms


Fuels made from material of biological origin, such as ethanol from fermentation of plant material, or biodiesel made from plant oils

biogenic emissions

Emissions from natural sources including vegetation, soil and oceans


The sphere of air, water and land in which all life is found

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carbon credits

A carbon credit has a money value. It represents what society is prepared to pay someone who reduces carbon dioxide in the atmosphere. Credits can be traded with people who need to emit carbon dioxide to run their businesses. The idea is to financially reward people who reduce greenhouse gas emissions

carbon cycle

The complete description of sources and sinks for carbon dioxide, and the associated rates of exchange

carbon dioxide (CO2)

A greenhouse gas, and the most important contributor to the enhanced greenhouse effect. A product of burning fossil fuels and respiration

carbon offsets

To offset an activity that releases greenhouse gases, money is contributed to a project that reduces greenhouse gas emissions or captures carbon dioxide

carbon monoxide (CO)

A gas that comes mainly from car exhausts. It is lethal at high doses

carbon sequestration

Capturing the carbon dioxide produced by coal-fired power stations and trapping it deep underground. This technology has not yet been proven in Australia, but some trials are underway

carbon sink

A natural process. Some of the carbon dioxide from the atmosphere is progressively absorbed and stored in the ocean. carbon dioxide is captured by plants and stored as wood and other plant material

CFCs (chlorofluorocarbons)

Human-made products containing carbon, chlorine and fluorine. Prior to 1990, used as propellant gases for sprays. Can deplete the ozone layer and also behave as greenhouse gases

climate change

A change in the long-term pattern of a weather parameter (such as temperature or rainfall), which may occur on global, regional or local scales. Globally, measurements are showing that the Earth's temperature is warming and that rainfall patterns are changing

coral bleaching

A small increase in the maximum temperature of the sea around coral reefs causes the coral to expel the algae living in its tissue. The coral loses its colour and can die. A future increase in the sea's acidity as more carbon dioxide dissolves into it will make it difficult for corals to grow their skeleton

CSIRO (Commonwealth Scientific and Industrial Research Organisation)

The principal scientific research organisation in Australia

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design concentrations

Maximum acceptable average exposure to a substance at ground level; used to calculate allowable emissions of substances from industries

detrimental level

The concentration of an indicator at or above which a substantial proportion of the exposed population may be affected or significant changes are likely to be caused to some segments of the environment

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ecological footprint

One method for representing an individual's impact on the planet. It measures how much nature we have, how much we use, and who uses it. It shows us how much biologically productive land and water a population (an individual, an organisation, a city, a country, or all of humanity) requires to support current levels of consumption and waste production, using prevailing technology

ecologically sustainable development

Development that improves the total quality of life, both now and in the future, in a way that maintains the ecological processes on which life depends

El Niño

This is the major Pacific Ocean water current that influences changes in weather along the eastern coast of Australia and the western coast of South America. El Niño does not happen every year, and is somewhat difficult to predict, but has a major influence on eastern Australia's rainfall

embodied energy

The energy consumed by all of the processes associated with the production of a product (such as a house, car, or an item of food), from the acquisition of natural resources to product delivery, including mining, manufacturing of materials and equipment, transport and administrative functions


Substances being released to the environment

emissions inventory

An estimate of the mass of all significant emissions to the atmosphere, over a specified time (usually a year) and within a defined area

emissions trading

An economic system for capping the amount of carbon dioxide produced, and requiring anyone who emits large amounts of carbon dioxide to buy a permit or credit

enhanced greenhouse effect

The total greenhouse effect, consisting of the natural greenhouse effect and the additional effect resulting from human activities that increase the atmospheric levels of greenhouse gases

EPA (Environment Protection Authority)

Government body established with a charter to protect the environment. EPA Victoria, for example, is charged with protecting the beneficial uses of the air, water and land from the adverse impact of wastes and unwanted noise. To do this it uses a range of mandatory and discretionary tools


Costs or benefits arising from decisions made by some individuals which impact on other individuals. An example could be the flooding of low-lying islands in the Pacific as a result of global warming due to Western industrialisation

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fossil fuels

Material rich in carbon formed from living organisms buried millions of years ago and burnt to provide energy. Coal, natural gas and oil are examples

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Gross Domestic Product


Some rocks deep below the Earth are hot enough to generate high-pressure steam when water is pumped through them. This potential energy source is being investigated for the production of electricity


One billion tonnes = 109 tonnes = 1012 kilograms

global climate models

Computer programs which model, describe and predict the behaviour of the atmosphere and oceans

global warming

The increase in temperature of the lower atmosphere due to human activity, especially the burning of fossil fuels and the clearing of land

greenhouse effect

A process whereby water vapour, carbon dioxide and other gases present in small quantities in the atmosphere 'trap' heat and warm the Earth's surface

greenhouse gases

Gases that contribute to the greenhouse effect. The main gases are carbon dioxide, water vapour and methane

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HCFCs (hydrochlorofluorocarbons)

A group of human-made compounds not found anywhere in nature. HCFC production began to take off in the 1980s after countries agreed to phase out the use of CFCs, which were found to be destroying the ozone layer. Most HCFCs are broken down in the lowest part of the atmosphere, and pose a much smaller risk to the ozone layer than CFCs


Substances composed of carbon and hydrogen

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A substance which is used as a measure of environmental change

indoor air quality

The totality of attributes of indoor air that affect a person's health and wellbeing

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One thousand tonnes = 103 tonnes = 106 kilograms

Kyoto Protocol

An international agreement decided in 1997 to reduce the amount of carbon dioxide being emitted by developed countries. Most developed countries agreed to reduce their emissions. A new agreement is to be developed in 2012

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One million tonnes = 106 tonnes = 109 kilograms

methane (CH4)

A greenhouse gas that is produced when plant and animal remains or wastes break down under special conditions

motor vehicle emissions

The gases and particles given off through the exhausts following the combustion of fuel in vehicle engines. Includes carbon dioxide, carbon monoxide, nitrogen oxides, hydrocarbons, small particles and water vapour

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National Environmental Protection Measure

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The Organisation for Economic Co-operation and Development


Substances containing carbon–carbon bonds

oxidant, oxidising agent

A substance that accepts electrons during chemical reactions. These reactions often involve oxygen, resulting in the formation of oxides. Rusting of steel is an example of this type of reaction

oxides of nitrogen

A group of chemicals containing nitrogen and oxygen in different proportions: examples include nitrogen dioxide (NO2), nitric oxide (NO) and nitrous oxide (N2O)


A gas with molecules comprising three atoms of oxygen (O3). Ozone is beneficial in the stratosphere because it absorbs damaging ultraviolet rays. In cities, air pollutants can react to form summer smog, containing higher than natural levels of ozone, which are harmful to human health

ozone layer

A region in the stratosphere where there is a small but important amount of ozone that provides a protective layer shielding the Earth from ultraviolet radiation

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Very small pieces of solid or liquid matter, such as soot, dust and smoke. They can be of different sizes. Those less than 10 micrometres in diameter are called PM10 (PM standing for particle matter) and those less than 2.5 micrometres in diameter are called PM2.5

per capita consumption

The average amount of a commodity used per person


The process whereby plants use solar energy to convert carbon dioxide and water into complex organic molecules and oxygen


A visible or measurable discharge of a pollutant from a given source. Examples include smoke from a chimney, exhaust from a poorly maintained car, or smoke rising from a bushfire

point source emissions

Emissions of waste from significant, fixed sources such as large industrial premises


A chemical that may reduce the quality of the environment


Reduction in the quality of the environment by one or more pollutants

ppm (parts per million)

A measure of small quantities. Usually expressed as a volumetric ratio ('ppmv'). If a pollutant concentration is 1 ppmv, it takes up 0.0001% of the air's volume

primary pollutant

A substance that is released directly into the atmosphere following a chemical reaction

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real prices

Income, costs, prices or interest rates that are adjusted for inflation


Aerobic oxidation of food or organic substances by organisms that releases usable energy, carbon dioxide and water

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satellite image

A picture of the Earth's surface taken from a satellite in space

secondary pollutants

Substances formed by many complex reactions between primary pollutants and other components in the atmosphere like water and oxygen

sick-building syndrome

A health problem caused by exposure to indoor pollutants. Symptoms include dizziness, headaches, coughing, sneezing, nausea, burning eyes and upper-respiratory problems. The symptoms are believed to arise from many causes that, while not clearly understood, are associated mainly with air-conditioned office buildings and new furnishings that emit volatile organic compounds


Places or processes which remove greenhouse gases from the atmosphere

solar radiation

Energy from the sun consisting of a spectrum of electromagnetic waves with many different wavelengths. Includes gamma rays, x-rays, ultraviolet, visible infrared and radio waves


Places or processes which release greenhouse gases into the atmosphere


The region of the atmosphere roughly 15–50 km above the Earth's surface

sulfur dioxide (SO2)

A gas mainly produced by burning coal, although some is emitted by diesel vehicles

summer smog

Air pollution formed from the chemical reaction of nitrogen dioxides and reactive organic compounds in the presence of sunlight to produce secondary pollutants such as ozone. Sometimes called 'photochemical smog'


A term being applied to managing the economy, environment and the needs of people. There are many definitions but key aspects are ensuring that there are adequate resources for future generations while having no long-lasting impact on the environment. This must be achieved while maintaining an economy and looking after the needs of all people

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Targets for the reduction of greenhouse emissions are being discussed to reduce the impact of climate change. Countries will be set greenhouse emission targets to be reached by a specified date

technical efficiency

A physical relationship between resources and products. It is achieved when a maximum level of output is obtained from a given level of input

tipping points

Scientists are investigating situations which could rapidly accelerate climate change once a specific point has been reached, leading to irreversible changes. For example, if the permafrost in the northern hemisphere melts, the carbon locked in the soil could be released, accelerating climate change


The lower layer of the atmosphere extending to 8–18 km above the Earth's surface. At the poles, the troposphere is 8 km thick whereas, at the equator, it is 18 km thick. In the troposphere, temperature normally decreases with height

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United Nations Environment Programme

urban airsheds

A body of air surrounding a city or township in which pollutants, once emitted, may concentrate

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VOCs (Volatile Organic Compounds)

Volatile organic compounds have boiling points between 50 °C and 260 °C. This term refers to hundreds of compounds including methane (CH4), benzene (C6H6), formaldehyde (CH20), chlorofluorocarbons (CFCs) and bromine-containing halons

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water vapour

The most important contributor to the natural greenhouse effect. Human activities contribute a tiny proportion of water vapour compared with the natural processes of evaporation and transpiration


The day-to-day changing atmospheric conditions. Data collected on the weather conditions of a region helps define its climate


World Health Organization

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