A time dependent index used to compare the radiative forcing, on a mass basis, of an impulse of a specific greenhouse gas relative to that of CO2. Gases included in the Kyoto Protocol are weighted in the first commitment period according to their GWP over a 100-year time horizon as published in the 1995 Second Assessment Report of the IPCC [Intergovernmental Panel on Climate Change]. In that report, a kilogram of methane, for example has a radiative force of about 21 times greater than that of a kilogram of CO2.The GWP of CO2 is defined as 1, thus methane has a GWP of 21 over the 100-year time horizon. (Source: International Petroleum Industry Environmental Conservation Association (IPIECA), Climate Change A Glossary of terms, 3rd Edition, January 2001. London, 2001).
An index describing the radiative characteristics of well mixed greenhouse gases that represents the combined effect of the differing times these gases remain in the atmosphere and their relative effectiveness in absorbing outgoing infrared radiation. This index approximates the time-integrated warming effect of a unit mass of a given greenhouse gas in today's atmosphere relative to that of carbon dioxide. The Conference of the Parties has adopted the Global Warming Potential values. (For GWP values for the first commitment period, see www.climatechange.gc.ca.)
A number that refers to the amount of global warming caused by a substance. The GWP is the ratio of the warming caused by a substance to the warming caused by a similar mass of carbon dioxide. Thus, the GWP of CO2 is defined to be 1.0 . CFC-12 has a GWP of 8,500, while CFC-11 has a GWP of 5,000. Various HCFCs and HFCs have GWPs ranging from 93 to 12,100. Water, a substitute in numerous end-uses, has a GWP of 0.
The GWP is an index of the strength of the radiative forcing induced by greenhouse gases. It is defined in the IPCC Report Shine et al. (1990) as the time-integrated commitment to climate forcing from the instantaneous release of 1 kg of a trace gas expressed relative to that from 1 kg of carbon dioxide.
The relative contribution of certain substances (greenhouse gases), e.g. carbon dioxide, methane, CFCs, HCFCs and halons, to the global warming effect when the substances are released to the atmosphere by combustion of oil, gas and coal (CO2), direct emission, leakage from refrigerating plants etc. The standard measure of GWP is relative to carbon dioxide (GWP=1.0), which is consistent with the Intergovernmental Panel on Climate Change (IPCC) indexing approach. The GWP can be given with 20, 100 or 500 years integration time horizon. There is not a complete agreement within the scientific community on what is the proper time horizon, but 100 years is most commonly used.
All greenhouse gases contribute to the 'trapping' of infrared radiation, hence heat, in the lower atmosphere. Due to the relative sizes of the greenhouse gas molecules, some trap more than other. Methane for instance has ten times the Global Warming Potential (GWP) of carbon dioxide. Carbon dioxide is used to compare the gases.
A measure of the potential of substances (normally gases or volatile liquids) to heat up the atmosphere. All measures of GWP are given relative to Carbon dioxide, the most well-known gas with global warming potential, which has a GWP of 1.
(GWP): the amount of global warming caused by substance, expressed as the ratio of the warming caused by one substance relative to that caused by a similar mass of carbon dioxide over a given period of time.
An index that shows the relative effects of various greenhouse gases in increasing global warming. GWPs are calculated as the amount of infra-red radiation absorbed by one kg of a gas over a period of 100 years. The GWP of carbon dioxide is one; the GWP of sulfur hexafluoride is 23,900.
Greenhouse impact relative to carbon dioxide.
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.
An index used 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 emission of one kilogram of a greenhouse gas to that from the emission of one kilogram of carbon dioxide over a fixed period of time, such as 100 years.
is a relative measure of the warming effect that the emission of a GHG might have on the Earth's atmosphere. It is calculated as the ratio of the time-integrated radiative forcing (i.e. the amount of heat-trapping potential) that would result from the emission of 1 kg of a given GHG to that from the emission of 1 kg of CO2. For example, the GWP for nitrous oxide (N2O) is 310, which means that 1 kg of N2O emissions is equivalent to 310 kg of CO2 emissions.
A system of multipliers which have been devised to enable warming effects of different gases to be compared.
The index used to translate the level of emissions of various gases into a common measure in order to compare their relative effect on climate change. GWPs are calculated as the ratio of the change 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). The GWP of CO2 is defined to be 1.0. (Source: Adapted from U.S. Environmental Protection Agency)
The GWP (Global Warming Potential) index expresses the climatic warming potential of a greenhouse gas relative to that of carbon dioxide, which by convention is set at 1. The GWP is actually calculated in terms of the 100 year warming potential of a kilogram (kg) of a gas relative to that of a kilogram of CO2.
Factor used to convert an amount of a given greenhouse gas into carbon dioxide-equivalent terms; for example, over a 100-year timeframe, methane is 21 times more powerful a greenhouse gas than carbon dioxide, so its GWP is 21. ()
The instantaneous radiative forcing that results from the addition of 1 kilogram of a gas to the atmosphere, relative to that of 1 kilogram of carbon dioxide.
A factor describing the radiative forcing impact (amount of warming) of one unit of a given GHG relative to one unit of CO2. For example, under the Kyoto Protocol, the GWP of methane is 21.
A system of multipliers devised to enable warming effects of different gases to be compared. The cumulative warming effect, over a specified time period, of an emission of a mass unit of CO2 is assigned the value of 1. Effects of emissions of a mass unit of non-CO2 greenhouse gases are estimated as multiples. For example, over the next 100 years, a gram of methane (CH4) in the atmosphere is currently estimated as having 23 times the warming effect as a gram of carbon dioxide; methane's 100-year GWP is thus 23. Estimates of GWP vary depending on the time-scale considered (e.g., 20-, 50-, or 100-year GWP), because the effects of some GHGs are more persistent than others.
The ratio of the warming caused by a substance to the warming caused by a similar mass of carbon dioxide. CFC-12, for example, has a GWP of 8,500, while water has a GWP of zero. (See: Class I Substance and Class II Substance.)
Global warming potential (GWP) is a measure of how much a given mass of greenhouse gas is estimated to contribute to global warming. It is a relative scale which compares the gas in question to that of the same mass of carbon dioxide (whose GWP is by definition 1). A GWP is calculated over a specific time interval and the value of this must be stated whenever a GWP is quoted or else the value is meaningless.
