Emissions
The GAINS model estimates the emissions of air pollutants and greenhouse gases (see also Pollutant) that exert radiative forcing and contribute to global warming. Specifically, GAINS estimates emissions of sulphur dioxide (\(SO_{2}\)), nitrogen oxides (\(NO_{x}\)), ammonia (\(NH_{3}\)), non-methane volatile organic compounds (VOC), mercury (Hg) [1], and primary emissions of particulate matter (PM), including fine (\(PM_{2.5}\)) and coarse (\(PM_{10}\)) PM as well as carbonaceous particles (BC, OC). In addition to these 5 air pollutants, GAINS also tracks emissions of some of the most potent greenhouse gases included in the Kyoto protocol: carbon dioxide (\(CO_{2}\)), methane (\(CH_{4}\)), and nitrous oxide (\(N_{2}O\)), as well as the three F-gases Hydrofluorocarbons (HFCs), Perfluorocarbons (PFCs), and Sulphur hexafluoride (SF6) [1].
GAINS quantifies the technical and economic interactions between mitigation measures for the above considered air pollutants and greenhouse gases. For each of the above pollutants, GAINS estimates emissions based on activity data levels (see also Activity data), uncontrolled emission factors, the removal efficiency of emission control measures and the extent to which such measures are applied (see also Control strategy):
where:
i, k, m, p |
Region, activity type, abatement measure, pollutant, respectively |
\(E_{i,p}\) |
Emissions of pollutant p (for SO2, NOx, VOC, NH3, PM2.5, CO2 , CH4, N2O, etc.) in country i |
\(A_{i,k}\) |
Activity data level of type k (e.g., coal consumption in power plants) in country i |
\(ef_{i,k,m,p}\) |
Emission factor of pollutant p for activity k in country i after application of control measure m |
\(x_{i,k,m,p}\) |
Share of total activity of type k in country i to which a control measure m for pollutant p is applied |
GAINS estimates future emissions according to Equation (1) by varying the activity levels along exogenous projections of anthropogenic driving forces and by adjusting the implementation rates of emission control measures.
Such approach allows capturing critical differences across economic sectors and countries that could justify differentiated emission reduction requirements in a cost-effective strategy. Both the country-specific activity levels and source-specific emission factors reflect the major structural differences in emission induced by specific sources and fuels, thereby accounting for the level at which emission abatement measures are applied. Additional information on the estimations of emissions per pollutant can be found under the page Technical reports.