Assimilation
Plants that require the process of photosynthesis to grow need to assimilate CO₂ . If the availability of CO₂ increases some plants are adapted to utilise this increase in order to enhance growth. Not all plant species will be able to utilise the enhanced levels of CO₂ and will thus not enhance their growth potential.

Astronomical forcing
Processes outside of the Earth-atmosphere system, affecting Earth's climate are termed astronomical forcing. These processes operate over extremely long time periods producing long term changes in the Earth's climate. These processes are collectively termed Milankovitch mechanisms and refer to the alteration of the Earth's orbit and axis (100 000 to 19 000 years).

Attenuation
The process whereby solar radiation is prevented from reaching the earth's surface through absorption, reflection, refraction, and scattering in the atmosphere.

Base period
In order to calculate if an event e.g. annual temperature, falls outside the normal range (an anomaly) it must be compared to the mean or average. The mean or average is calculate from a long time series of data usually 30 years or longer this is called the base-period. In most cases the base-period in time series calculations is from 1961 to 1990

Billion tons
Billion tons (Gt): One Billion is given the prefix G meaning giga, in terms of scientific notation it is equal to 109or in decimal notation 1 000 000 000.

Biomass
Non-fossilised organic matter both aboveground and belowground, both living and dead e.g., trees, crops, grasses, tree litter, roots etc.

Biosphere
That component of the Earth system that contains life in its various forms, which includes its living organisms and derived organic matter (e.g. litter, detritus, soil).

Bogussing
The technique whereby artificial TCLV's are added to a model simulation is termed bogussing.

BP
BP is a term used in radio-carbon dating to define isotopic age back from a reference point of 1950AD.

Carbon flux
Transfer of carbon from one carbon pool to another in units of measurement of mass per unit area and time (e.g., t C ha^-1 y^-1).

Carbon pool
A reservoir. A system which has the capacity to accumulate or release carbon. Examples of carbon pools are forest biomass, wood products, soils and atmosphere. The units are mass (e.g., t C).

Carbon stock
The absolute quantity of carbon held within a pool at a specified time.

CFC's
Chloroflourocarbons or halocarbon's were, until recently, produced for use in air-conditioning and refrigeration units, and as propellants in aerosol cans. CFC's not only acts as a greenhouse gas but actively depletes upper atmospheric Ozone.

CH₄
Methane is a naturally occurring greenhouse gas who's concentration is increasing due to human activity e.g. agriculture and waste disposal.

Climate surfaces
Climate surfaces are virtual layers of regularly grided atmospheric data created from a collection of station data and other observations. The station and other observational data form an irregular surface of data that through the process of interpolation can be recalculated onto a regular grid.

CO₂
Carbon Dioxide is the most significant naturally occurring greenhouse gas who's concentration has increased particularly due to fossil fuel usage and land use change.

CO₂ fertilisation
Plants that require the process of photosynthesis to grow need to assimilate CO2. If the availability of CO2 increases some plants are adapted to utilise this increase in order to enhance growth. Not all plant species will be able to utilise the enhanced levels of CO2 and will thus not enhance their growth potential.

Confidence level
The potential inaccuracy of a model can be accounted for by applying confidence levels to model output. This method allows a range of plausible values to be presented and presents the current output as a function of that range. The larger the range of values the lower the confidence in the model.

COP
The Conference of the Parties (COP) is the supreme body of the UNFCCC. It currently meets once a year to review the Convention's progress.

CSIRO
Commonwealth Scientific and Industrial Research Organisation

Diurnal range
The difference between the maximum temperature and minimum temperature over the period of 24hrs is defined as the diurnal range.

El Niño
The eastward movement of the Walker circulation in response to warm ocean water development off the Peruvian coast is termed an El Niño event. This type of event is associated with below normal rainfall over tropical Australia

ENSO
The term ENSO refers to El Niño-Southern Oscillation. Intensity: the intensity of El Niño and La Niña events can be assessed in two ways. The first is to analyse the Southern Oscillation Index (SOI) which is a measure of the mean surface air pressure. The second method is to measure the release of latent heat associated with ENSO's i.e. during ENSO events warm SST's release energy in the form of latent heat. This in turn affects global temperatures.

ENSO frequency
The rate at which El Niño events occur is defined as ENSO frequency.

EU
As a regional economic integration organization, the European Union can be and is a Party to the UNFCCC. However, it does not have a separate vote from its members. The EU is also a Party to the Kyoto Protocol.

Flexibility mechanisms
The Kyoto Protocol contain three mechanisms (Emissions Trading, Joint Implementation and Clean Development) that allow for some international activities to count towards a country's emissions reduction target. Emissions Trading provides for the trading of emissions entitlements and may include trading in carbon credits. Joint Implementation allows for projects to be conducted between two developed countries with the reduction in emissions able to be used by the investing country to help meet its target. Clean Development Mechanism allows for Annex 1 countries to conduct projects in developing countries and to count the credit for emissions reduction.

Fossil fuels
Fuel that contains carbon and/or hydrogen eg. coal, natural gas and oil, formed by the decomposition of pre-historic organisms such as trees and other vegetation.

GHG
Greenhouse Gases

Heat island
The use of heat absorptive materials, along with the modification of air flow due to the presence of tall buildings causes localised heating effects. The heat island effect is most pronounced at night when building material begins to emit long-wave radiation.

Intensities
The intensity of tropical cyclones can be measured in two ways. The first is to measure the central pressure tendency of the feature (the lower the central pressure the greater the cyclone intensity). The second method of determining cyclone intensity is to measure the wind speeds at the centre of the cyclone.

IPCC Revised 1996 Guidelines for National Greenhouse Gas Inventories
The Guidelines consisting of three volumes (a Workbook, Reference Manual and Reporting Instructions) were prepared by a joint IPCC-OECD group. The Revised 1996 Guidelines are identified as the basis for reporting under the Kyoto Protocol for the first commitment period. They consider anthropogenic fluxes of greenhouse gases.

Intensity
The intensity of El Niño and La Niña events can be assessed in two ways. The first is to analyse the Southern Oscillation Index (SOI) which is a measure of the mean surface air pressure. The second method is to measure the release of latent heat associated with ENSO's i.e. during ENSO events warm SST's release energy in the form of latent heat. This in turn affects global temperatures.

Interglacial
The period of relative warming between two glacial periods.

Interpolation
The technique of creating a series of continuos values between two or more data points is called interpolation.

Land Use
The social and economic purposes for which land is managed (e.g. grazing, cultivation, commercial forestry, conservation, infrastructure).

La Niña
An intensification of the Walker Circulation associated with the development of cold ocean waters off the Peruvian coast is termed a La Niña event. In tropical Australia this type of event is associated with above normal rainfall.

LULUCF
Land Use, Land Use Change and Forestry activities include afforestation, reforestation, deforestation and other land uses by humans. These activities change the natural rates of exchange of carbon dioxide between the biosphere and the atmosphere and are an important factor in assessing anthropogenic global warming and climate change.

N₂O
Nitrous oxide is a gas that can be produced by both natural and anthropogenic processes. The major anthropogenic sources of N₂O are from agriculture and manufacturing.

Negative & positive correlation
The extent to which one variable changes as a result of a change in another variable is termed correlation. If one variable tends to increase when another decreases the correlation is defined as negative. When one variable increases in response to increase in another variable the correlation is defined as positive.

NOAA
National Oceanic and Atmospheric Administration

O₃
Ozone is an important naturally occurring gas in both the upper and lower atmosphere. It's most important role in the atmosphere is to prevent extremely short wavelengths of radiation from reaching the earth's surface.

OECD
The Organization for Economic Cooperation and Development consists of 29 industrialized countries.

Paleo
The term 'paleo' is a prefix meaning 'old' or 'ancient'. Anomalies: Events that represent deviations from the average or normal behaviour are called anomalies. ppmv: The measure of individual gas concentration is derived from identifying the molecular occurrence in a fixed volume for example ppmv is equal to a measure of the concentration in part per million by volume.

Parameterisation
As models are limited to the number of numerical equations they can contain, a number of small-scale physical relationships cannot be accurately modelled. For this reason only the average effects/values of these relationships are included in the model. This process is defined as parameterisation.

ppmv
The measure of individual gas concentration is derived from identifying the molecular occurrence in a fixed volume for example ppmv is equal to a measure of the concentration in part per million by volume.

Proxy data
In addition to the instrumental measurement of El Niño's and La Niña's, evidence of such events can be inferred from corals, tree rings and ice cores in order to extend the time series back in time. This particular type of data is referred to a proxy data.

Variations in atmospheric conditions can be determined by using parameters that are effected by the changes in condition. For example, the development of growth rings in trees can be linked to variations in rainfall and temperature. As this type of data survives for long periods of time, a record of variation in rainfall or temperature can be extended back beyond the beginning of observational data.

QELRC
Quantified emission limitation or reduction (QELRC) commitment for Parties to the Kyoto Protocol are expressed as a percentage of their gross 1990 greenhouse gas emissions.

Radiative forcing
A change in the energy available to the global Earth/atmosphere system is termed a radiative forcing.

Rangelands
Rangelands refer to areas of land used extensively by grazing animals. Native grasses, shrubs and woody vegetation generally covers the area. The rangeland is also characterised by low annual rainfall.

Salinisation
Salinisation occurs when soils become inundated with mineral salts from the lower soil profile. As salt is water soluble it can move through the soil profile in solution. During period of extreme heat the water is removed from the soil through evaporation, leaving the salt behind in the upper soil layers. If this process continues long enough, the concentration of salt becomes too high for most plants and they die.

Sequestration
The process of increasing the carbon content of a carbon pool other than the atmosphere.

Sink
Any process or mechanism which removes a greenhouse gas, an aerosol, or a precursor of a greenhouse gas from the atmosphere. A given pool can be a sink for atmospheric carbon if, during a given time interval, more carbon is flowing into it than is flowing out.

SLATS
The Statewide Landcover And Trees Study is a major remote sensing project of the Queensland Department of Natural Resources. SLATS gathers accurate land cover and land cover change information for the State. (http://www.dnr.qld.gov.au/slats/).

Soil carbon stocks
Refers to the relevant carbon in the soil. It includes various forms of soil organic carbon (humus) and inorganic soil carbon and charcoal. It excludes belowground biomass (e.g., roots, bulbs, etc.) as well as soil fauna.

Southern Oscillation
An eastward or westward movement of the Walker Circulation is defined as the Southern Oscillation. The oscillation is prompted by changes in surface ocean temperatures in the equatorial Pacific Ocean.

Solar radiation
An object that possesses a temperature above absolute zero Kelvin (0 degrees K or -273.16 degrees C) releases energy in the form of radiation. Energy emitted by the sun is characterised by short wavelength radiation in the ultra-violet, visible and infra-red wavebands (0.3µm to 10µm).

Storm Track
The direction in which a tropical cyclone moves during its life is called a storm track.

Temporal
A change in atmospheric variability over time would be referred to temporal variability.

Terrestrial Radiation
Energy emitted from the earth's surface in the visible and infra-red wavebands (3µm to over 100µm) Attenuation: The process whereby solar radiation is prevented from reaching the earth's surface through absorption, reflection, refraction, and scattering in the atmosphere.

Thermal Expansion
The enhanced radiative forcing resulting from increased anthropogenic emissions will serve to increase the atmospheric temperatures over time. The increase in atmospheric temperature will in turn be translated to the ocean through boundary-layer interaction. As the oceans begin to warm the increase in available energy will cause the oceans to expand.

Time series
An historical record of atmospheric data is termed a time series.

Trade Winds
Air masses in the Pacific Ocean that move parallel to the equator (0 to 10 degrees North and South) in both the Northern and Southern Hemispheres are defined as the Trade winds. In the Northern Hemisphere the winds curve along the equator from the northeast whereas in the Southern Hemisphere the winds curve towards the equator from the southeast.

Transient
The term transient refers to a gradual increase in GHG's according to IPCC approved projections.

Troup SOI
One way to calculate the SOI is by using the Troup method established in 1965 that calculates a standardised anomaly of the Mean Sea Level Pressure difference between Tahiti and Darwin. It is calculated as follows:

Pdiff = (average Tahiti MSLP for the month) - (average Darwin MSLP for the month), PdiffAve = long term average of Pdiff for the month in question, and Stdev(Pdiff) = standard deviation of Pdiff for the month in question.

Vortices
The circulation of air around a localised axis, where windspeeds are at a maximum at the centre of the feature is termed a vortex.

Walker Circulation
The Walker Circulation is a semi-permanent series of circulation cells running parallel to the equator in the Southern Hemisphere. The circulation cells consist of an upward and downward limb of moving air, along with upper and surface air movement. The upward moving air limbs are usually located over the continents of the Southern Hemisphere and the downward limbs positioned over each of the southern oceans. These series of individual cells link with one another and extent around the entire Southern Hemisphere.