Pollutants
The assessment of indicators for pollutants with local and regional effects is
done in the same way as for greenhouse gases. The KPI denotes specific emissions
of the pollutants NOX (nitrogen oxide) SOX (sulphur oxide) and PM2.5. (particulate
matter- PM) expressed in grams of pollutant per tonne-km. (PM2,5 is the fraction of
PM with a size below 2.5 micrometers).
For heavy vehicles, ships and trains, specific emissions (NOx and PM) are
usually given in grams per kWh of engine power. That must be transformed to
emissions per tonne-km through energy efficiency data and load factors similar to
those employed for GHG above. Note that the gram per kWh in this case usually
refers to the energy output of the engine, not the energy input as for GHG. Sulphur
emissions are most commonly communicated through data on sulphur content in
fuels and can be transformed to grams/tonne-km. Specific Emissions of NOx
depend mainly on engine technology, although some differences can be attributed
to fuels (relevant mainly for ships). Specific Emissions of SOx vary with the
sulphur content in fuels. For road diesel, there is a common standard (10 ppm)
within the EU; for ships the sulphur content may vary from below 1,000 ppm
(0.1 %) (ships at berth in community ports and inland waterway vessels) to over