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The glossary provides definitions for terms that are used within this site. Please use this section as a reference and feel free to contact us for any questions you may have.


Aerosols commonly refer to aerosol sprays (or spray cans) which are a type of canister that sprays an aerosol. Some examples are: hairsprays, spray paints, electronic equipment cleaners, emergency horns, insecticides and deodorants.They use what is called a "propellant" to force out the liquid in the can (the "payload") and create a mist. Propellants commonly used in spray cans are HFCs, carbon dioxide, nitrogen and hydrocarbons. HFCs and carbon dioxide are greenhouse gases but HFCs have very high GWPs and are dangerous greenhouse gases.

Air Conditioning Systems:
The common use of air conditioning is to mean cooling and often dehumidification of indoor air, typically via refrigeration. The most common uses of modern air conditioners are for comfort cooling in buildings and transportation vehicles. Air conditioners cool air by use a compressor to cause pressure changes between two compartments, and actively pump a refrigerant around. Commonly used refrigerants are HCFCs (R-22, used in most homes today) and HFCs (R-134a, used in most cars) have replaced most CFC use. HCFCs in turn are being phased out under the Montreal Protocol and replaced by hydrofluorocarbons (HFCs), such as R-410A, which lack chlorine.3 These fluorinated gases have very high GWPs and are dangerous greenhouse gases.


Anaerobic is a technical word which literally means without air (where "air" is almost always used to mean oxygen), as opposed to aerobic.3

The mixture of gases surrounding the Earth. The Earth's atmosphere consists of about 79.1 percent nitrogen (by volume), 20.9 percent oxygen, 0.036 percent carbon dioxide and trace amounts of other gases. The atmosphere can be divided into a number of layers. The layer nearest the Earth is the troposphere, then come the stratosphere, the mesosphere, and finally the thermosphere. There is relatively little mixing of gases between layers.1

Made by people or resulting from human activities. Usually used in the context of emissions that are produced as a result of human activities.


Carbon Dioxide (CO2):
A naturally occurring gas, and also a by-product of burning fossil fuels and biomass, as well as land-use changes and other industrial processes. It is the principal anthropogenic greenhouse gas that affects the Earth's radiative balance. It is the reference gas against which other greenhouse gases are measured and therefore has a Global Warming Potential of 1.2

Catalytic Converters:
Catalytic converters are "estimated" to account for 50% of total nitrous oxide emissions to atmosphere. While N2O emissions in these concentrations are not harmful to human health, it is a potent greenhouse gas with almost 300 times the heat trapping ability of CO2.3

Climate in a narrow sense is usually defined as the "average weather," or more rigorously, as the statistical description in terms of the mean and variability of relevant quantities over a period of time ranging from months to thousands of years. The classical period is 3 decades, as defined by the World Meteorological Organization (WMO). These quantities are most often surface variables such as temperature, precipitation, and wind. Climate in a wider sense is the state, including a statistical description, of the climate system.2

Climate Change:
Climate change refers to any significant change in measures of climate (such as temperature, precipitation, or wind) lasting for an extended period (decades or longer).2 The modern climate change we are experiencing today results from human activities that change the atmosphere's composition (e.g. through burning fossil fuels, industruial production, etc.)

Coal is a fossil fuel that is composed primarily of carbon along with assorted other elements, including sulfur. It is the largest single source of fuel for the generation of electricity world-wide, as well as the largest source of carbon dioxide emissions, which have been implicated as the primary cause of global warming.3


The breakdown of matter by bacteria and fungi. It changes the chemical composition and physical appearance of the materials.1

Those practices or processes that result in the conversion of forested lands for non-forest uses. This is often cited as one of the major causes of the enhanced greenhouse effect for two reasons: 1) the burning or decomposition of the wood releases carbon dioxide; and 2) trees that once removed carbon dioxide from the atmosphere in the process of photosynthesis are no longer present.1

Direct Emissions:

Emissions that are caused directly by actions taken by an individual or an organization. Examples are: emissions coming from your car when you drive to work or emissions that result from the electricity that you use at home or work.


Releases of gases to the atmosphere (e.g., the release of carbon dioxide during fuel combustion).1

The capacity for doing work as measured by the capability of doing work (potential energy) or the conversion of this capability to motion (kinetic energy). Energy has several forms, some of which are easily convertible and can be changed to another form for useful work. Most of the world’s convertible energy comes from fossil fuels that are burned to produce heat that is then used as a transfer medium to mechanical or other means in order to accomplish tasks.1

Energy Mix:

The proportional relationship between all used energy sources (percentage of energy from fossil fuel, nuclear, geothermal, solar, wind and hydroelectric sources).6

Enteric Fermentation:
A digestive process by which carbohydrates are broken down by microorganisms into simple molecules for absorption into the bloodstream of an animal.1 Large quantities of methane emissions are produced during this process.


Fluorinated Gases:
Hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride(SF6) are usually grouped together and called collectively fluorinated gases. HFCs, PFCs, SF6 are synthetic, powerful greenhouse gases. These gases are typically emitted in smaller quantities, but because they are potent greenhouse gases, they are sometimes referred to as High Global Warming Potential gases (“High GWP gases”).4


The word styrofoam is often used by the general public as a generic term to indicate any brand of polystyrene foam. Coffee cups, cooler or packaging material are typically white in color and are made of expanded polystyrene beads. Expanded polystyrene is produced from a mixture of about 90-95% polystyrene and 5-10% gaseous blowing agent.3 HFCs (like HFC-245fa, HFC-365mfc, HFC-134a and HFC-152a) as well as HCFCs (like HCFC-22, HCFC-142b, HCFC-141b and HCFC-124) are typically used as blowing agents. All of these gases have very high GWPs and are dangerous greenhouse gases.

Fossil Fuels:
A general term for buried combustible geologic deposits of organic materials, formed from decayed plants and animals that have been converted to crude oil, coal, natural gas, or heavy oils by exposure to heat and pressure in the earth's crust over hundreds of millions of years.1 See coal, petroleum, oil, natural gas.


G8 Nations:
The Group of Eight (G8) is an international forum for the governments of Canada, France, Germany, Italy, Japan, Russia, the United Kingdom and the United States. Together, the eight countries represent about 65 percent of the world economy.3

Global Warming:
Global warming is an average increase in the temperature of the atmosphere near the Earth's surface and in the troposphere, which can contribute to changes in global climate patterns. In common usage, "global warming" often refers to the warming that can occur as a result of increased emissions of greenhouse gases from human activities.2

Global Warming Potential:
The index used to translate the level of emissions of various gases into a common measure in order to compare the relative radiative forcing of different gases without directly calculating the changes in atmospheric concentrations. GWPs are calculated as the ratio of the radiative forcing that would result from the emissions of one kilogram of a greenhouse gas to that from the emission of one kilogram of carbon dioxide over a period of time (usually 100 years).1

Greenhouse Effect:
Trapping and build-up of heat in the atmosphere (troposphere) near the earth’s surface. Some of the heat flowing back toward space from the earth's surface is absorbed by greenhouse gases in the atmosphere and then reradiated back toward the earth’s surface. If the atmospheric concentrations of these greenhouse gases rise, the average temperature of the lower atmosphere will gradually increase.1 See greenhouse gas

Greenhouse Gas (GHG):
Any gas that absorbs infrared radiation in the atmosphere. Greenhouse gases include, but are not limited to, water vapor, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6).1 See carbon dioxide, methane, nitrous oxide, hydrochlorofluorocarbon, hydrofluorocarbon, perfluorocarbon, sulfur hexafluoride.

Green Energy:
Green energy is a term describing what is thought to be environmentally friendly sources of power and energy. Typically, this refers to renewable and non-polluting energy sources.


Form of kinetic energy that flows from one body to another when there is a temperature difference between the two bodies. Heat always flows spontaneously from a hot sample of matter to a colder sample of matter. This is one way to state the second law of thermodynamics.1 See temperature.

High Global Warming Potential Gases:
Hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride(SF6) are usually grouped together and called collectively high GWP gases because they are potent greenhouse gases and have high GWPs.4

Human Activities:
Human activites can be classified as activities that would not occur in natural environments without human influences. Some types of human activites include industry, agriculture, mining, transportation, construction, and habitations.3

Hydrofluorocarbons (HFCs):
Compounds containing only hydrogen, fluorine, and carbon atoms. HFCs are emitted as by-products of industrial processes and are also used in manufacturing. They do not significantly deplete the stratospheric ozone layer, but they are powerful greenhouse gases with global warming potentials ranging from 140 (HFC-152a) to 11,700 (HFC-23).2


Indirect Emissions:

Indirect emissions are the opposite of direct emissions. They are emissions that are created as a result of decisions taken by an individual or an organization, but that could not be controlled by the individual or organization. Examples are: emissions cause by the transportation of fruits and vegtables from the farm to the supermarket or emissions as a result of the extraction, refinement and distribution of fossil fuels like petroleum.

Industrial Revolution:
The Industrial Revolution was a major shift of technological, socioeconomic, and cultural conditions in the late 18th century and early 19th century. It was the industrial revolution that gave birth to environmental pollution as we know it today. The emergence of great factories and consumption of immense quantities of coal and other fossil fuels gave rise to unprecedented air pollution and the large volume of industrial chemical discharges added to the growing load of untreated human waste.3

Industrialized Nations:
The term industrialized nation is synonymous with the term developed country and is used to categorize countries with developed economies. Countries with high gross domestic product (GDP) per capita often fit the above description of a developed economy.3 Also known as the First World, high-income countries, and the North.


Kyoto Protocol:
The Kyoto Protocol is a protocol to the international Framework Convention on Climate Change with the objective of reducing greenhouse gases that cause climate change.

It was adopted on 11 December 1997 by the 3rd Conference of the Parties, which was meeting in Kyoto, and it entered into force on 16 February 2005. As of June 2008, 182 parties have ratified the protocol. Of these, 36 developed cg countries (plus the EU as a party in its own right) are required to reduce greenhouse gas emissions to the levels specified for each of them in the treaty (representing over 61.6% of emissions from Annex I countries), with three more countries intending to participate. One hundred thirty-seven (137) developing countries have ratified the protocol, including Brazil, China and India, but have no obligation beyond monitoring and reporting emissions. The United States has not ratified the treaty.3


Land waste disposal site in which waste is generally spread in thin layers, compacted, and covered with a fresh layer of soil each day.1

Livestock is the term used to refer (singularly or plurally) to a domesticated animal intentionally reared in an agricultural setting to make produce such as food or fibre, or for its labour.3


Dung and urine of animals (livestock) that produce large amounts of methane and nitrous oxide emissions.

Methane (CH4):
A hydrocarbon that is a greenhouse gas with a global warming potential most recently estimated at 23 times that of carbon dioxide (CO2). Methane is produced through anaerobic (without oxygen) decomposition of waste in landfills, animal digestion, decomposition of animal wastes, production and distribution of natural gas and petroleum, coal production, and incomplete fossil fuel combustion.2


Natural Gas:
Underground deposits of gases consisting of 50 to 90 percent methane (CH4) and small amounts of heavier gaseous hydrocarbon compounds such as propane (C3H4) and butane (C4H10).1

Natural Processes:

A process existing in or produced by nature (rather than by the intent of human beings).

Nitrous Oxide (N2O):

A powerful greenhouse gas with a global warming potential of 296 times that of carbon dioxide (CO2). Major sources of nitrous oxide include soil cultivation practices, especially the use of commercial and organic fertilizers, fossil fuel combustion, nitric acid production, and biomass burning.2


See petroleum

Organic Matter:

Organic matter (or organic material) is matter which has come from a recently living organism; is capable of decay, or the product of decay; or is composed of organic compounds.3


Per capita:
A Latin phrase meaning by or for each individual person.3

Perfluorocarbons (PFCs):
A group of human-made chemicals composed of carbon and fluorine only. PFCs are emitted as by-products of industrial processes and are also used in manufacturing. They are powerful greenhouse gases: CF4 has a global warming potential (GWP) of 5,700 and C2F6 has a GWP of 11,900.2

A generic term applied to oil and oil products in all forms, such as crude oil, lease condensate, unfinished oils, petroleum products, natural gas plant liquids, and non-hydrocarbon compounds blended into finished petroleum products.1


Collecting and reprocessing a resource so it can be used again. An example is collecting aluminum cans, melting them down, and using the aluminum to make new cans or other aluminum products.1

Refrigerators/Refrigeration Systems:
Refrigeration systems remove heat from an enclosed space, or from a substance, and rejecting it elsewhere for the primary purpose of lowering the temperature of the enclosed space or substance and then maintaining that lower temperature.3 Refrigerators are used in homes but they are used extensively for the food and produce industries in whats called the "cooling chain". Meat and produce are kept in cool or freezing temperatures at every step between the farm and the supermarket. Storage rooms, refrigerated transportation, chilled depots as well as all the refrigeration units used at the supermarket itself have their toll. As with air conditioning systems, HFCs and HCFCs are commonly used as refrigerants espcially HFC-134a. These fluorinated gases have very high GWPs and are dangerous greenhouse gases.

The process whereby living organisms convert organic matter to CO2 , releasing energy and consuming O2.2

Ruminant Animals:

Ruminant animals, such as cattle, sheep, and goats, all emit methane through a digestive process that is unique to ruminant animals called enteric fermentation. In the rumen, or large fore-stomach, of these animals, enteric fermentation converts feed into products that can be digested and utilized by the animal. The beef and dairy cattle sector of the livestock industry is the largest emitter of methane. Livestock production systems can also emit other greenhouse gases such as nitrous oxide and carbon dioxide.2


CO2 sequestration is the storage of carbon dioxide (usually captured from the "atmosphere") in a solid material through biological or physical processes.3

A reservoir that uptakes a pollutant from another part of its cycle. Soil and trees tend to act as natural sinks for carbon.1

Sulfur Hexafluoride (SF6):
A colorless gas soluble in alcohol and ether, slightly soluble in water. A very powerful greenhouse gas used primarily in electrical transmission and distribution systems and as a dielectric in electronics. The global warming potential of SF6 is 22,200.2

Synthetic Fertilizer:
Commercially prepared mixtures of plant nutrients such as nitrates, phosphates, and potassium applied to the soil to restore fertility and increase crop yields.1


Measure of the average speed of motion of the atoms or molecules in a substance or combination of substances at a given moment. See heat.1

The lowest part of the atmosphere from the surface to about 10 km in altitude in mid-latitudes (ranging from 9 km in high latitudes to 16 km in the tropics on average) where clouds and "weather" phenomena occur.2


United Nations Framework Convention on Climate Change (UNFCCC):
The Convention on Climate Change sets an overall framework for intergovernmental efforts to tackle the challenge posed by climate change. It recognizes that the climate system is a shared resource whose stability can be affected by industrial and other emissions of carbon dioxide and other greenhouse gases. The Convention enjoys near universal membership, with 189 countries having ratified.
Under the Convention, governments:

  • Gather and share information on greenhouse gas emissions, national policies and best practices.
  • Launch national strategies for addressing greenhouse gas emissions and adapting to expected impacts, including the provision of financial and technological support to developing countries.
  • Cooperate in preparing for adaptation to the impacts of climate change.

The Convention entered into force on 21 March 1994.1


Atmospheric condition at any given time or place. It is measured in terms of such things as wind, temperature, humidity, atmospheric pressure, cloudiness, and precipitation. In most places, weather can change from hour-to-hour, day-to-day, and season-to-season. Climate in a narrow sense is usually defined as the "average weather", or more rigorously, as the statistical description in terms of the mean and variability of relevant quantities over a period of time ranging from months to thousands or millions of years. The classical period is 30 years, as defined by the World Meteorological Organization (WMO). These quantities are most often surface variables such as temperature, precipitation, and wind. Climate in a wider sense is the state, including a statistical description, of the climate system. A simple way of remembering the difference is that climate is what you expect (e.g. cold winters) and 'weather' is what you get (e.g. a blizzard). See climate.2

1United Nations Framework Convention on Climate Change Glossaries

2EPA's Climate Change Glossary

3Wikipedia Encyclopedia

4EPA's Greenhouse Gas Emissions Overview

5Canadian Pollution Prevention Information Clearinghouse

6The Solarserver Solar Lexicon

7The Free Dictionary

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