The ETM compares future CO2 emissions to 1990 emission levels, as this is a common reference point in (inter)national climate policy. In contrast to the present and future scenario year, the 1990 emissions number is not calculated (dynamically) by the model, but instead is a fixed input number researched for each region.
For all countries in the ETM, the 1990 emissions number is based on data from the European Environmental Agency. The following categories are included:
|Fuel Combustion by sector||1.AA|
Other emissions, such as other feedstock and fugitive emissions are not included in the 1990 number as these emissions are out of scope of the ETM.
For regional datasets, no uniform, international source exists detailing historic emissions on a fine-grained geographical level. As such, 1990 emissions are researched for each region individually.
For subregions of the Netherlands, data is used from RIVM. They report 1990 emissions on a municipality level. However, this data does not comply with the main principles of the ETM's CO2 calculation:
- Emissions are reported by geographical location. This means that a municipality with a power plant within its border is assigned the full emissions of the plant. Conversely, no emissions for electricity use are taken into account for municipalities without power plants.
- The regional data does not conform to IPCC definitions. This means that emissions of biomass are included.
To be able to compare 1990 emissions to the present and future emission levels calculated by the ETM, Quintel applies the following correction method to the data:
- First, for all municipalities 1990 CO2 emissions are calculated for all sectors except the energy sector
- Secondly, each municipality total is divided by the Dutch total, both excluding energy sector emissions. This results in a 'scaling factor' per municipality. For example, municipality X has 3% of total Dutch 1990 emissions excluding the energy sector.
- Finally, this scaling factor is multiplied with the total Dutch 1990 emissions including the energy sector to obtain an estimate per municipality.
This results in an estimate of the full 1990 municipality emissions that is in compliance with the ETM principles. This method implicitly assumes that the 1990 Dutch energy sector emissions can be allocated to a municipality level proportionally to a municipality's non-energy sector 1990 emissions.
Two caveats apply to this method, making it difficult to assess the quality of the outcomes:
- For several sectors, the RIVM source data is based on estimates rather than measurements.
- The above method has not been tested extensively, due to a lack of reference data.