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Data Sources and Methods for the National Greenhouse Gas Emissions Indicators

Caveats and limitations

Annex 7 of the National Inventory Report (NIR) presents the uncertainty assessment for Canada’s greenhouse gas (GHG) emissions. Further details on uncertainty related to specific sectors can be found in the uncertainty sections of chapters 3 through 8 of the NIR.

The sum of emissions from all provinces and territories does not equate to the national total, because emissions from some sources are estimated only at the national level. In particular, GHG estimates associated with the consumption of perfluorocarbons (PFCs) or sulphur hexafluoride (SF6) in refrigeration, air conditioning and semiconductor manufacturing are not included in the provincial and territorial totals; only SF6 emissions from electrical equipment have been included. Nevertheless, the trends in emissions from provinces and territories are considered representative of the actual emission trends in these jurisdictions.

The application of quality assurance and quality control (QA/QC) procedures is an essential requirement of the GHG inventory development and submission process. QA/QC procedures ensure and improve transparency, consistency, comparability, completeness and confidence in the national emissions for the purpose of meeting Canada’s reporting commitments under the United Nations Framework Convention on Climate Change (UNFCCC). Annex 6 of the NIR provides a complete description of the QA/QC procedures.

As part of the continuous improvement process, recalculations are performed annually on Canada’s previously reported GHG emission estimates, to reflect updates to source data and estimation methodology. Chapter 9 (section 9.1) of the NIR provides a summary of the recalculations that occurred due to methodological changes and/or refinements since the previous submission, with a brief description, justification and summary of individual impacts on previously reported emission estimates.