Did the UNFCCC review process improve the national GHG inventory submissions?

Parties to the Climate Convention have set up an elaborate system of reporting and review ensuring Parties inform each other on the progress towards the targets of the convention. This paper analyzes annual national emission inventory submissions, both as to the effort needed for review and the resulting changes in reported emissions. Expert review teams and the Convention's secretariat invest about 4000 working days each year to run the reviews. About one quarter of this is needed for the secretariat. Although estimates for emissions differ between successive submissions, updated estimates remain for a very large part within the uncertainty ranges. There does not seem to be any significant change in each Party's estimated emissions between the six different submissions analyzed in this study. Based on this we propose a simpler approach for the review. Review teams could decide not to pay attention on smaller issues in the submissions, provided that the submission is prepared taking the Convention's transparency, consistency, comparability, completeness and accuracy criteria into account. Such a simplification might be necessary for the international community to be able to continue to ensure the quality of nationally reported data when implementing decisions and provisions of the recent Paris Agreement.