Key Terms

Note: Many of these terms found in the glossary below contain more than one definition, but from different sources.


Afforestation” is the direct human-induced conversion of land that has not been forested for a period of at least 50 years to forested land through planting, seeding and/or the human-induced promotion of natural seed sources (UNFCCC 2001).

Carbon Credit

A generic term to assign a value to a reduction or offset of greenhouse gas emissions. A carbon credit is usually equivalent to one metric tonne of carbon dioxide equivalent(CO2-e). A carbon credit can be used by a business or individual to reduce their carbon footprint by investing in an activity that has reduced or sequestered greenhouse gases at another site (EPA, 2008).

Note that not all carbon dioxide offsets are purely carbon.

Carbon Dioxide (CO2)

Carbon and Oxygen compound which makes up about 0.04% of our atmosphere.  It is typically associated with Global Warming because it serves as a greenhouse gas.

Carbon Offset

Carbon offsetting is where consumers pay to reduce greenhouse gases (GHG) from the atmosphere. This is usually to counteract or compensate for pollution. 

A carbon offset is a monetary investment in a project or activity elsewhere that abates greenhouse gas (GHG) emissions or sequesters carbon from the atmosphere that is used to compensate for GHG emissions from your own activities. Offsets can be bought by a business or individual in the voluntary market (or within a trading scheme), a carbon offset usually represents one tonne of CO2-e (EPA 2008).

Carbon Sequestration

The process of removing carbon from the atmosphere and depositing it in a reservoir (UNFCCC).

Carbon Sink

Any process, activity or mechanism which removes a greenhouse gas, an aerosol or a precursor of a greenhouse gas from the atmosphere. Forests and other vegetation are considered sinks because they remove carbon dioxide through photosynthesis (UNFCCC).

Carbon Source

Any process, activity or mechanism which contributes to carbon being added or released into the atmosphere.

Chlorofluorocarbon (CFCs)

CFCs are a compound consisting of chlorine, fluorine, and carbon. They are typically referred as being harmful to the atmosphere and responsible for ozone depletion.  CFCs are commonly used as refrigerants, solvents, and foam blowing agents (EPA) The Montreal Protocol, banned the production of most CFCs by the year 2000.


Change of forest with depletion of tree crown cover to less than 10 percent. The clearing of forests and the conversion of land to non-forest uses (World Bank 2000).


The establishment of forest, naturally or artificially, on an area, whether previously carrying forest or not (Ford-Robertson 1971).

Forest Preservation

Compination of Forest Management and any attempt to preserve natural forests or repair degraded land.

Fossil Fuels

Fossil fuels are hydrocarbons, primarily coal, fuel oil or natural gas, formed from the remains of dead plants and animals. (Science Daily)

Greenhouse Gases (GHG)

Gaseous constituents of the atmosphere, both natural and anthropogenic, that absorb and re-emit infrared radiation (UN Definition).

The atmospheric gases responsible for causing global warming and climate change. The major GHGs are carbon dioxide (CO2), methane (CH4) and nitrous oxide (N20). Less prevalent --but very powerful -- greenhouse gases are hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluoride (SF6). (UNFCCC Definition).

Kyoto Protocol

The Kyoto Protocol is an international agreement linked to the United Nations Framework Convention on Climate Change. The major feature of the Kyoto Protocol is that it sets binding targets for 37 industrialized countries and the European community for reducing greenhouse gas (GHG) emissions .These amount to an average of five per cent against 1990 levels over the five-year period 2008-2012. (UNFCCC Definition)The Kyoto Protocol was adopted in Kyoto, Japan, on 11 December 1997

Old-Growth Forests

Pertains to forests that have been around for a very long time. They are carbon sinks, but no longer capture or sequester large amounts of carbon. 


Non-forest ecosystem - Grasslands, shrublands, chaparral, wetlands, deserts, etc., where trees are not the dominant life form, although they may be present as scattered individuals or in patches.

Non-forest - Land not primarily intended for growing or supporting forest. Includes alpine, rock, slide, non-productive burn, non-productive brush, swamp or muskeg, cultivated, cleared, urban, open range, wild hay meadow, clay bank, gravel bar, and other categories.(UNFCCC, 2001)


Planting of forests on lands that have previously contained forests but that have been converted to some other use (EPA).

 “Reforestation” is the direct human-induced conversion of non-forested land to forested land through planting, seeding and/or the human-induced promotion of natural seed sources, on land that was forested but that has been converted to non-forested land. For the first commitment period, reforestation activities will be limited to reforestation occurring on those lands that did not contain forest on 31 December 1989 (UNFCCC 2001)

Young-Growth Forests

Youth-growth Forests, aka Fast-Growth Forests, are just that, young and fast growing.  Fast growing forests are said to capture or sequester large amounds of carbon in their biomass.