File : D5.1
Author : Glen Peters (CICERO) et al.
There are many independent estimates of GHG emissions, but very little understanding either qualitatively or quantitatively of the differences between these estimates. One of the biggest reasons for differences between independent estimates is differences in system boundaries. While these issues have been discussed qualitatively before, this report develops this and adds quantitative detail. While this report is focused on the EU, it does consider estimates in other key regions and the global level. We focus on a detailed quantitative comparison of fossil CO2 emissions, illustrating that even subtle and poorly communicated differences in system boundaries can lead to significant quantitative differences. While uncertainties are rarely reported for different datasets, uncertainties based on comparing independent datasets are probably overestimates. For land-based CO2 emissions, our comparisons and discussions are more qualitative, but we expand on previous discussions to pay closer attention to Harvested Wood Products and bioenergy. Both these fluxes are important for regional carbon budgets. Follow up work will progressively detail more quantitative analysis of the differences between land-based CO2 estimates. This report does not discuss non-CO2 emissions, which are covered in another deliverable. Our analysis highlights the importance of consistency in and awareness of system boundaries when verifying emission estimates. We further outline areas where more research is needed to better detail and understand differences in system boundaries.
Figure 1 : Annual CO2 emissions for the EU28 from various sources
