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Definitions and Glossary

The following section provides definitions for commonly used words and acronyms used in Canada's National Inventory Report and by the United Nations Framework Convention on Climate Change (UNFCCC).

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |


Annex I Countries

The group of countries included in Annex I of the UNFCCC, including all of the Organization for Economic Co-operation and Development (OECD) countries and economies in transition. By default, the other countries who have ratified or acceded to the UNFCCC but are not included in Annex I are referred to as Non-Annex I countries.

Annex II Countries

The group of countries included in Annex II of the UNFCCC, including all the OECD countries. Annex II countries are expected to provide financial resources to assist developing countries to comply with their UNFCCC obligations and transfer environmentally sound technologies.

Annex B Countries

The group of countries included in Annex B to the Kyoto Protocol that have agreed to a target for reducing their greenhouse-gas emissions. Annex B countries includes all of the Annex I countries except for Turkey and Belarus.


Anthropogenic means caused or produced by human activities. Sources of anthropogenic greenhouse gas emissions include the burning of fossil fuels, deforestation, raising of livestock, use of fertilizers, and so on.

Assigned Amount (AA)

Under the Kyoto Protocol, the assigned amount is the quantity of greenhouse-gas emissions that an Annex B country has accepted as its target for limiting or reducing emissions in the first commitment period (2008 to 2012). The assigned amount is the country's total greenhouse-gas emissions in 1990 multiplied by five (for the five-year commitment period) and by the percentage it agreed to as listed in Annex B of the Kyoto Protocol (for example, 94% for Canada). The allowed emissions are divided into assigned amount units (AAUs), also known as Kyoto units. Countries that have AAUs to spare (emissions permitted but not used) can sell the excess capacity to countries over their target.



The total mass of living organisms in a given area or volume; recently dead plant material is often included as dead biomass. The quantity of biomass is expressed as a dry weight or as the energy, carbon, or nitrogen content.1 Biomass derived products, by-products, residues and waste occur from agriculture, forestry and related industries as well as the non-fossilized and biodegradable organic fractions of industrial and municipal wastes. Biomass derived products also include gases and liquids recovered from the decomposition of non-fossilized and biodegradable organic material.


Carbon Capture and Storage

A process consisting of the separation of CO2 from industrial and energy-related sources, transport to a storage location (reservoir), and long-term isolation from the atmosphere.1

Carbon Dioxide (CO2)

Carbon dioxide, also called carbonic acid gas, is a naturally occurring colourless, odorless, incombustible gas formed during respiration, combustion, decomposition of organic substances, and the reaction of acids with carbonates. CO2 is used in carbonated drinks, fire extinguishers, as dry ice for refrigeration. CO2 is present in the Earth’s atmosphere at low concentrations and is constantly being removed from the air by its direct absorption into water and by plants through photosynthesis. In turn, it is naturally released into the air by plant and animal respiration, decay of plant and soil organic matter, outgassing from water surfaces. Small amounts of CO2 are also injected directly into the atmosphere by volcanic emissions and through slow geological processes such as the weathering of rock.2 Carbon dioxide acts as a greenhouse gas and anthropogenic sources of CO2 emissions include combustion of fossil fuels and biomass to produce energy, building heating and cooling, land-use changes including deforestation, manufacture of cement and other industrial processes.

Carbon Dioxide Equivalent (CO2 eq)

Often greenhouse gas emissions are calculated in terms of how much CO2 would be required to produce a similar warming effect. This is called the carbon dioxide equivalent (CO2 eq) value and is calculated by multiplying the amount of the gas by its associated global warming potential (GWP).

Certified Emission Reduction (CER)

A tradeable unit under the Kyoto Protocol's emissions trading scheme, equal to one tonne of CO2 emissions reduced or removed, generated from clean development mechanism (CDM) project activities. Two special types of CERs called temporary certified emission reductions (tCERs) and long-term certified emission reductions (lCERs) are issued for emission removals from afforestation and reforestation CDM projects.3


The average pattern of weather usually taken over a 30-year period for a particular region. Climatic elements include precipitation, temperature, humidity, sunshine, wind velocity, phenomena such as fog, frost and hailstorms, and other measures of the weather.

Climate Change

Changes in long-term weather patterns caused by natural phenomena and human activities that alter the chemical composition of the atmosphere through the build-up of greenhouse gases which trap heat and reflect it back to the earth’s surface

Common Reporting Format (CRF) Tables

Common Reporting Format tables are a series of standardized data tables containing mainly numerical information which are submitted electronically as part of Canada’s annual submission to the UNFCCC.

Conference of the Parties (COP)

The supreme body of the UNFCCC, comprising countries with the right to vote, that have ratified or acceded to the convention. It currently meets once a year to review the Convention's progress.1



Deforestation estimates include all emissions and removals from Forest Conversion that have occurred since January 1st, 1990 (see the definition of Forest Conversion below). The reporting of annual deforestation estimates is mandatory for the first commitment period of the Kyoto Protocol (2008-2012).


Economies in Transition

Countries with their economies changing from a planned economic system to a market economy.1

Emission Reduction Unit (ERU)

A tradeable unit under the Kyoto Protocol's emissions trading scheme (equal to one tonne of CO2 reduced or removed) generated from a joint implementation (JI) project defined in Article 6 of the Kyoto Protocol.


The release of greenhouse gases into the atmosphere over a specified period of time.


Forest Conversion

A change in land use that involves the permanent conversion of forest land to a non-forest land category, such as agricultural land, industrial land, infrastructure, settlement, and so on. Forest conversion excludes a harvest that is followed by forest re-growth. Emissions and removals from forest conversion are reported in the Land Use, Land-use Change and Forestry Sector of the greenhouse gas inventory, under the sub-categories Land converted to cropland, Land converted to wetlands, and Land converted to settlements. For additional clarity these estimates are also reported under the memo item Forest Conversion.


Global Warming Potential (GWP)

A GWP is the time-integrated change in radiative forcing (effectiveness in absorbing outgoing infrared radiation) due to the instantaneous release of 1 kilogram (kg) of the gas expressed relative to the radiative forcing from the release of 1 kg of CO2. The concept of global warming potentials has been developed to allow scientists and policy-makers to compare the ability of each greenhouse gas to trap heat in the atmosphere relative to CO2.

Greenhouse Gases (GHGs)

Greenhouse gases are those gaseous constituents of the atmosphere, both natural and anthropogenic, that absorb and emit radiation at specific wavelengths within the spectrum of infrared radiation emitted by the Earth's surface, the atmosphere and clouds. This property causes the greenhouse effect. Water vapour (H2O), carbon dioxide (CO2), nitrous oxide (N2O), methane (CH4) and ozone (O3) are the primary greenhouse gases in the earth's atmosphere. Moreover, there are a number of entirely human-made greenhouse gases in the atmosphere, such as sulphur hexafluoride (SF6), hydrofluorocarbons (HFCs), and perfluorocarbons (PFCs).1


Hydrofluorocarbons (HFCs)

Hydrofluorocarbons (HFCs) are a class of synthetic chemical compounds that contain only fluorine, carbon and hydrogen. They are commonly used as replacements for ozone-depleting substances, such as chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) and halons in various applications including refrigeration, fire-extinguishing, semi-conductor manufacturing and foam blowing. HFCs do not deplete the ozone layer, however they are powerful greenhouse gases.


Intergovernmental Panel on Climate Change (IPCC)

Established in 1988 by the World Meteorological Organization and the United Nations Environment Programme, the IPCC surveys world-wide scientific and technical literature, publishes assessment reports that are widely recognized as the most credible existing sources of information on climate change and develops methodologies and good practice guidance. The IPCC is independent of the UNFCCC.


An accounting of the amount of greenhouse gases emitted to or removed from the atmosphere over a specific period of time (for example, one year).



Key Category

A category that is prioritized within the national inventory system because its estimate has a significant influence on a country's total inventory of direct greenhouse gases in terms of the absolute level of emissions, the trend in emissions or both.

Kyoto Protocol

The Kyoto Protocol is an international agreement linked to the UNFCCC that sets binding targets for the reduction of greenhouse gas emissions by industrialized countries, in addition to the commitments included in the UNFCCC. Annex B countries agreed to reduce their anthropogenic greenhouse gas emissions (CO2, CH4, N2O, PFCs, HFCs, and SF6) by at least 5% below 1990 levels in the commitment period 2008-2012. The Kyoto Protocol came into force on February 16th, 2005.


Land Use, Land Use Change and Forestry (LULUCF)

A greenhouse gas inventory sector that covers emissions and removals of greenhouse gases resulting from direct human-induced land use, land-use change and forestry activities including wildfires, controlled burning, and land conversion.


Monitoring Accounting and Reporting System (MARS)

Canada's national, multidisciplinary framework for monitoring, accounting and reporting emissions and removals in managed lands. The MARS framework provides a means for coordinating, planning and integrating the activities of many groups of scientists and experts across several government levels and research institutions and ensurs that the best available information and data from scientific research are integrated into the LULUCF sector of the inventory.

Meeting of the Parties

The Conference of the Parties (COP) of the UNFCCC serves as the Meeting of the Parties (MOP), which is the supreme body of the Kyoto Protocol. Only parties to the Kyoto Protocol may participate in MOP deliberations and make decisions.

Methane (CH4)

Methane is a colorless, odorless, flammable gas that is the simplest hydrocarbon and is the major constituent of natural gas. Like carbon dioxide, methane is exchanged naturally between the Earth’s surface and the atmosphere, however, methane is removed from the atmosphere primarily through chemical processes involving the chemical hydroxyl radical, OH.2 These chemical interactions finally produce water and carbon dioxide. A small amount of methane is also absorbed directly by soils. Methane is present in the Earth’s atmosphere at low concentrations and acts as a greenhouse gas. Methane is produced naturally during the decomposition of plant or organic matter in the absence of oxygen, as well as released from wetlands (including rice paddies), through the digestive processes of certain insects and ruminant animals such as termites, sheep and cattle. Methane is also released from industrial processes, fossil fuel extraction, coal mines, incomplete fossil fuel combustion, and garbage decomposition in landfills.

Montreal Protocol

The Montreal Protocol on Substances that Deplete the Ozone Layer was adopted in Montreal in 1987, and controls the consumption and production of chemicals that destroy stratospheric ozone, such as chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs).


National Inventory Report (NIR)

Canada’s National Inventory Report provides a complete accounting of the six greenhouse gases required under the UNFCCC, along with information on the activities that cause emissions and removals and a description of the estimation methodologies used.

National Inventory System

A national system is a requirement of Article 5.1 of the Kyoto Protocol. The national inventory system encompasses the institutional, legal and procedural arrangements necessary to ensure that Parties meet their reporting obligations, that quality inventories are prepared, and that proper documentation and archiving occur in order to facilitate third-party review and to assess compliance with the Kyoto Protocol.

National Registry

A national registry is a requirement of Article 7.4 of the Kyoto Protocol. The national registry will track trading and record holdings of Kyoto units.

Nitrous Oxide (N2O)

Nitrous oxide is a colourless, nonflammable, sweet-smelling gas. Used as an anesthetic in dentistry and surgery, nitrous oxide is released naturally from oceans, by bacteria in soils, and from animal wastes. Other sources of nitrous oxide emissions include the industrial production of nylon and nitric acid, combustion of fossil fuels and biomass, soil cultivation practices, and the use of commercial and organic fertilizers. Nitrous oxide is present in the Earth’s atmosphere at low concentrations and acts as a greenhouse gas.


Organization for Economic Co-operation and Development (OECD)

The OECD is an international economic organzation of 30 developed countries, originally established to help administer the Marshall Plan for the reconstruction of Europe after World War II. The OECD now provides a setting where governments compare policy experiences, seek answers to common problems, identify good practice and coordinate domestic and international policies.


Perfluorocarbons (PFCs)

Perfluorocarbons (PFCs) are a group of synthetic chemicals composed of carbon and fluorine only. PFCs are powerful greenhouse gases that were introduced as alternatives to ozone depleting substances. PFCs replace chlorofluorocarbons (CFCs) in manufacturing semiconductors and are also emitted as a by-product of industrial processes and manufacturing.



Removal Unit (RMU)

A tradeable unit under the Kyoto Protocol's emissions trading scheme, equal to one tonne of CO2 emissions reduced or removed due to land use, land-use change and forestry (LULUCF) activities described under Article 3, paragraphs 3 and 4 of the Kyoto Protocol.



A greenhouse gas sink is a process, activity or mechanism that removes a greenhouse gas from the atmosphere.


A greenhouse gas source is a process, activity or mechanism that releases a greenhouse gas to the atmosphere.

Sulphur Hexafluoride (SF6)

Sulphur hexafluoride (SF6) is a synthetic gas that is colourless, odorless, non-toxic (except when exposed to extreme temperatures) and non-flammable. SF6 acts as a greenhouse gas due to its very high heat trapping capacity. SF6 is primarily used in the electricity industry as insulating gas for high voltage equipment and as cover gas in the magnesium industry to prevent oxidation (combustion) of molten magnesium. In lesser amounts, SF6 is used in the electronic industry in manufacturing of semiconductors, and also as tracer gas for gas dispersion studies in the industrial and laboratory settings.



The tendency of greenhouse gas emissions to increase or decrease over time due to economic, technological and/or other societal drivers.



An expression of the degree to which a value is unknown (for example, the future state of the climate system). Uncertainty can result from lack of information or from disagreement about what is known or even knowable. It may have many types of sources, from quantifiable errors in the data to ambiguously defined concepts or terminology, or uncertain projections of human behavior. Uncertainty can therefore be represented by quantitative measures (for example, a range of values calculated by various models) or by qualitative statements (for example, reflecting the judgment of a team of experts).1

United Nations Framework Convention on Climate Change (UNFCCC)

The UNFCCC was signed at the 1992 Earth Summit in Rio de Janeiro and has now been ratified by 192 countries. The Convention sets an overall framework for intergovernmental efforts to tackle climate change with the ultimate objective of stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. Under the Convention government gather and share information on greenhouse gas emissions, national policies and best practices, launch national strategies and cooperate in preparing for adaptation to the impacts of climate change.



Verification of national inventories includes the use of a set of simple checks for completeness and accuracy. Verification of the Canada's National Inventory includes the use of third-party information to confirm the veracity of the inventory.



State of the atmosphere at a given time and place and is usually reported as temperature, air pressure, humidity, wind, cloudiness, and precipitation.





01 Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change - Annex II Glossary - IPCC Fourth Assessment Report - Intergovernmental Panel on Climate Change, 2007

02 An Introduction to Climate Change - A Canadian Perspective; Environment Canada 2005

03 Kyoto Protocol Reference Manual on Accounting of Emissions and Assigned Amount - United Nations Framework Convention on Climate Change, 2008