How to compare global and local pollutant emissions

The reduction of pollutants like nitrogen oxides or particulate matter is currently one of the drivers for the development of better power train concepts. Additionally, stricter regulations on CO2 emissions will become active in the next years. One big question is, how to compare the impact of pollutants, which act locally and short-term, with the impact of global greenhouse gases like CO2, acting on a long-term base. Which of both has to be seen as more harmful? Is it possible to develop a comparative factor to rate the ecological fingerprint of both? In our work an approach is proposed to estimate a common ″damage indicator″ based on the monetary calculation of the ″followup costs″ (external costs). Such calculations have been done up to now either for the local pollutant emissions or for the impact of global acting greenhouse gases. Our attempt is, to combine these two fully different classes of emission with the damage cost estimation. Although parts of these estimations contain significant uncertainties, already interesting preliminary conclusions can be drawn. As an example, the ecological impact of real-drive emissions of some passenger cars will be discussed comparatively. It is estimated that the resulting external costs are in the order of 1 ct/km based on realistic real drive emissions, where the CO2 contribution is the dominant factor for the non-diesel driven cars.