2.2 Selection of Appropriate Emission Quantification Methods
The next step in the development of an emission inventory report is to quantify emissions using a tiered approach, depending on the availability of the data. The following tiers are employed:
- A detailed approach in which emissions are based on measured or modeled data.
- A mid-tier approach in which emissions are calculated with the basic equation: E = A x EF (see Text Box 1).
- A pragmatic approach where emissions are estimated as an extrapolation of data available or calculated for another region/scale.
In the detailed approach, emissions are measured or modeled, for instance, plant individual reporting of industrial emissions to E-PRTR or emission quantified based on a detailed sewage system model or road traffic model.
In the mid-tier approach, the basic equation (Text Box 1) comes from general guidance documents on setting up emission inventory reports, like EMEP/CORINAIR emission inventory guidebook (EEA, 2009).
The pragmatic approach was used in cases where the activity data (e.g., fuel consumption, mileage, etc.) used in the mid-tier approach were not available for the region/scale for which an inventory needs to be developed. In such case, a linear relationship was assumed between the emission sources in question and another well-defined parameters. For instance, a linear relationship could be assumed between the emissions from marine shipping allocated to a specific port and the gross tonnage of goods transferred in that port instead of the fuel consumption (which is not available).