Relative global warming potentials

GWP, global warming potential, relative per emitted quantity to CO2, weighted according to residence time. 

Global warming potential relative to CO2 for a 100-year time frame. 

Global Warming Potential. This value is based on known global warming factors for gases such as N2O, CH4 and various organic solvents, expressed relative to CO2. A mass weighted summation is used as for the acidification potential. 

Ozone Depletion Potential. This is calculated in a similar manner to global warming potential and is expressed relative to CFC-11. Factors for all common gases having significant effects on the ozone layer have been calculated. 

Table 6.9 Global warming potentials (CWP) relative to constant future CO2 concentration (source IPCC 2001)...

Also shown are the relative global warming potentials, using C02 as the reference and for the two time horizons of 20 and 100 years, respectively (IPCC, 1996). The apparently disproportionate effects of CH4, NzO, and 03 relative to C02 are due to the fact that C02 was present from natural processes in large concentrations even in preindustrial times and is such a strong... 

TABLE 14-4 Direct Radiative Forcings and Global Warming Potential for the Major Greenhouse Gases" Relative to C02... 

Gas Concentration Total radiative forcing6 (Wm 2) Relative global warming potential time horizon" ... 

FIGURE 14-23 Global warming potentials (GWP) relative to C02 for N20, C2F(), HFC-134a, and HCFC-225ca as a function of time (adapted from IPCC, 1996). 

TABLE 14.7 Direct Radiative Forcings per Unit Concentration for Some Fluorinated Compounds0 and Relative Global Warming Potentials Taking GWP(CFC-11) = 1.0b,c or GWP (C02) = 1.0... 

The database provides also numerical values for the ozone depletion potential and the global warming potential, which are calculated relative to carbon dioxide or to CECll (CCI3F). The EPA regulations for the solvents are indicated. 

Table 6.5 Direct global warming potential (GWP) of tropospheric gases (molecule for molecule) relative to C02 (after Highwood Shine 2000 Jain et al.2000 Houghton et al. 2001)...

Table 6. Estimated relative global warming potentials of greenhouse gases, weight basis (Bunce, 1994).

Compare the global warming potentials of different GHGs and discuss the relative role of various chemical compounds in greenhouse effects. 

The ability of these compounds to absorb infrared radiation varies widely from compound to compound, as does their life in the atmosphere before they undergo photochemical reactions or are absorbed in the oceans or on land. Methane has a concentration of only l.Vppmv in the troposphere, which is much less than that of carbon dioxide. On the other hand, each molecule of methane has a global warming potential (GWP) value that is 21 times that of carbon dioxide over the course of 100 years. (Note the GWP value has been developed to compare the ability of each greenhouse gas to trap infrared radiation over 100 years relative to another gas by convention, carbon dioxide has a GWP of 1.) Although methane has a relatively short lifetime (a few years)... 

---