MnrAq

Annex 4 235
Figure 24: Time series of adjustments due to primary and secondary sources of uncertainty
Table 16 – Results of quantitative uncertainty analysis on top-down statistics (million tonnes)
Marine Sector 2007 2008 2009 2010 2011
Total marine fuel consumption (reported) 249.2 243.7 235.9 253.0 253.5
Adjustment for export-import discrepancy 71.5 79.4 78.0 59.0 56.0
Adjustment for fuel transfers balance 8.1 8.1 7.5 7.5 8.2
Adjusted top-down marine fuel estimate 328.8 331.2 321.4 319.5 317.7
Figure 25: Adjusted marine fuel sales based on quantitative uncertainty results (2007–2011)
Export-import discrepancy represents the primary source of uncertainty, as measured by the quantity of
adjustment that is supported by our analysis. This discrepancy exists because the total fuel volumes reported
as exports exceed the total fuel volumes reported as imports. Evidence associating the export-import
discrepancy with marine fuels includes the known but unquantified potential to misallocate bunker fuel sales
as exports, as documented above. The magnitude of this error has increased during the period of globalization,