Carbon dioxide
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 human-caused 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.
Carbon dioxide
equivalent
A metric measure used to compare the emissions from various greenhouse
gases based upon their global warming potential (GWP). Carbon dioxide
equivalents are commonly expressed as “million metric tons of carbon dioxide
equivalents (MMTCO 2 Eq).” The carbon dioxide equivalent for a gas is
derived by multiplying the tons of the gas by the associated global warming
potential, i.e., MMTCO 2 Eq ¼ (million metric tons of a gas) * (GWP of the
gas).
Carbon dioxide
fertilization
The enhancement of the growth of plants as a result of increased atmospheric
CO 2 concentration. Depending on their mechanism of photosynthesis, certain
types of plants are more sensitive to changes in atmospheric CO 2
concentration.
Carbon
footprint
The total amount of greenhouse gases that are emitted into the atmosphere
each year by a person, family, building, organization, or company. A persons
carbon footprint includes greenhouse gas emissions from fuel that an individual burns directly, such as by heating a home or riding in a car. It also includes
greenhouse gases that come from producing the goods or services that the
individual uses, including emissions from power plants that make electricity,
factories that make products, and landfills where trash gets sent.
Carbon
sequestration
(a) Storage of carbon through natural or technological processes in biomass or
in deep geological formations. (b) Terrestrial, or biologic, carbon sequestration is the process by which trees and plants absorb carbon dioxide, release the
oxygen, and store the carbon. Geologic sequestration is one step in the process
of carbon capture and sequestration (CCS) and involves injecting carbon
dioxide deep underground where it stays almost permanently.
Carbon tetrachloride (CCl 4 )
A compound consisting of one carbon atom and four chlorine atoms. Carbon
tetrachloride was widely used as a raw material in many industrial uses,
including the production of chlorofluorocarbons and as a solvent. Solvent
use ended when it was discovered to be carcinogenic. It is also used as a
catalyst to deliver chlorine ions to certain processes. Its ozone depletion
potential is 1.2.
Chlorofluorocarbon (CFC)
A compound consisting of chlorine, fluorine, and carbon. Chlorofluorocarbons (CFCs) are very stable in the troposphere. They move to the stratosphere
and are broken down by strong ultraviolet light, where they release chlorine
atoms that then deplete the ozone layer. CFCs were commonly used as
refrigerants, solvents, and foam blowing agents. The most common CFCs
were CFC-11, CFC-12, CFC-113, CFC-114, and CFC-115. CFCs have been
phased out in the USA, with a few exceptions. CFCs are the gases covered
under the 1987 Montreal Protocol and used for refrigeration, air conditioning,
packaging, insulation, solvents, or aerosol propellants. Since they are not
destroyed in the lower atmosphere, CFCs drift into the upper atmosphere
where, given suitable conditions, they break down ozone. These gases are
being replaced by other compounds: hydrochlorofluorocarbons, an interim
replacement for CFCs that are also covered under the Montreal Protocol, and
hydrofluorocarbons, which are covered under the Kyoto Protocol. All these
substances are also greenhouse gases.
Class I ozonedepleting
substance
One of several groups of chemicals with an ozone depletion potential of 0.2 or
higher. Class I ozone-depleting substances listed in the Clean Air Act include
chlorofluorocarbons, halons, carbon tetrachloride, methyl chloroform
hydrobromofluorocarbons, and methyl bromide.
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L. K. Wang et al.
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 human-caused 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.
Carbon dioxide
equivalent
A metric measure used to compare the emissions from various greenhouse
gases based upon their global warming potential (GWP). Carbon dioxide
equivalents are commonly expressed as “million metric tons of carbon dioxide
equivalents (MMTCO 2 Eq).” The carbon dioxide equivalent for a gas is
derived by multiplying the tons of the gas by the associated global warming
potential, i.e., MMTCO 2 Eq ¼ (million metric tons of a gas) * (GWP of the
gas).
Carbon dioxide
fertilization
The enhancement of the growth of plants as a result of increased atmospheric
CO 2 concentration. Depending on their mechanism of photosynthesis, certain
types of plants are more sensitive to changes in atmospheric CO 2
concentration.
Carbon
footprint
The total amount of greenhouse gases that are emitted into the atmosphere
each year by a person, family, building, organization, or company. A persons
carbon footprint includes greenhouse gas emissions from fuel that an individual burns directly, such as by heating a home or riding in a car. It also includes
greenhouse gases that come from producing the goods or services that the
individual uses, including emissions from power plants that make electricity,
factories that make products, and landfills where trash gets sent.
Carbon
sequestration
(a) Storage of carbon through natural or technological processes in biomass or
in deep geological formations. (b) Terrestrial, or biologic, carbon sequestration is the process by which trees and plants absorb carbon dioxide, release the
oxygen, and store the carbon. Geologic sequestration is one step in the process
of carbon capture and sequestration (CCS) and involves injecting carbon
dioxide deep underground where it stays almost permanently.
Carbon tetrachloride (CCl 4 )
A compound consisting of one carbon atom and four chlorine atoms. Carbon
tetrachloride was widely used as a raw material in many industrial uses,
including the production of chlorofluorocarbons and as a solvent. Solvent
use ended when it was discovered to be carcinogenic. It is also used as a
catalyst to deliver chlorine ions to certain processes. Its ozone depletion
potential is 1.2.
Chlorofluorocarbon (CFC)
A compound consisting of chlorine, fluorine, and carbon. Chlorofluorocarbons (CFCs) are very stable in the troposphere. They move to the stratosphere
and are broken down by strong ultraviolet light, where they release chlorine
atoms that then deplete the ozone layer. CFCs were commonly used as
refrigerants, solvents, and foam blowing agents. The most common CFCs
were CFC-11, CFC-12, CFC-113, CFC-114, and CFC-115. CFCs have been
phased out in the USA, with a few exceptions. CFCs are the gases covered
under the 1987 Montreal Protocol and used for refrigeration, air conditioning,
packaging, insulation, solvents, or aerosol propellants. Since they are not
destroyed in the lower atmosphere, CFCs drift into the upper atmosphere
where, given suitable conditions, they break down ozone. These gases are
being replaced by other compounds: hydrochlorofluorocarbons, an interim
replacement for CFCs that are also covered under the Montreal Protocol, and
hydrofluorocarbons, which are covered under the Kyoto Protocol. All these
substances are also greenhouse gases.
Class I ozonedepleting
substance
One of several groups of chemicals with an ozone depletion potential of 0.2 or
higher. Class I ozone-depleting substances listed in the Clean Air Act include
chlorofluorocarbons, halons, carbon tetrachloride, methyl chloroform
hydrobromofluorocarbons, and methyl bromide.
26
L. K. Wang et al.