The Norwegian Emission Inventory 2011

The Norwegian emission inventory is a joint undertaking between the Climate and Pollution Agency1 and Statistics Norway. Statistics Norway is responsible for the collection and development of activity data, and emission figures are derived from models operated by Statistics Norway. The Climate and Pollution Agency is responsible for the emission factors, for providing data from specific industries and sources and for considering the quality, and assuring necessary updating, of emission models like, e.g., the road traffic model and calculation of methane emissions from landfills. Emission data are used for a range of national applications and for international reporting. The Climate and Pollution Agency is responsible for the Norwegian reporting to United Nations Framework Convention on Climate Change (UNFCCC) and to United Nations Economic Commission Europe (UN-ECE).

This report documents the methodologies used in the Norwegian emission inventory of greenhouse gases (GHG), acidifying pollutants, heavy metals (HM) and persistent organic pollutants (POPs). The documentation will also serve as a part of the National Inventory Report submitted by Norway to the United Nations Framework Convention on Climate Change (UNFCCC), and as documentation of the reported emissions to UNECE for the pollutants restricted by CLRTAP (Convention on Long-Range Transboundary Air Pollution). LULUCF is not considered in this report, see the National Inventory Report (Climate and Pollution Agency 2011b) for documentation on this topic.

This report replaces the previous documentation of the emission model (Sandmo 2010), and is the latest annually updated version of a report edited by Britta Hoem in 2005. The most important changes since last year’s documentation are:

• To define the different economic sectors in the Norwegian emission model, the standard industrial classification SIC2007 has replaced the previous SIC2002 (Appendix F)

• A new model for calculating emissions to air (HBEFA) from road traffic has been incorporated. The time series for CH4, N2O, NOX, NMVOC, CO, NH3 and particle emissions from road traffic have thus been recalculated. There have been some changes made to the activity data, e.g. a new data source on annual driving lengths has been utilised and more detailed information on traffic activity has been taken into account

• Emissions of CH4 from gas distribution have for the first time been included in the inventory

• The calculation method for NOx emissions from production of silicon metal has been revised

• For national navigation, revised emission factors for NOX emissions from gas engines and emissions of particulate matter from oil based fuels and LNG have been introduced

• A new uncertainty analysis for greenhouse gases has been performed, and the main results are documented in this report

Furthermore, there are lower emission figures for CH4 for all years since 1990 due to revisions of Statistics Norway’s waste statistics, but there are no methodological changes in the calculation of these emissions. There have also been several minor changes in the emission figures, e.g. due to changes in figures on energy combustion. Chapter 8 Recalculations gives a more thorough description of changes in the most recent emission calculations.