III Comparison of uncertainty in different emission trading schemes In : Proceedings of the International Workshop on Uncertainty in Greenhouse Gas Inventories

Emission trading in the EU will begin in 2005, covering the least uncertain emission sources of greenhouse gas emission inventories (CO2 from combustion and from selected industrial processes in large installations). If the Kyoto Protocol enters into force, the emission trading covering all gases (CO2, CH4, N2O, HFCs, PFCs and SF6) and sectors (energy, industry, agriculture, waste, land use, land-use change and forestry (LULUCF)) will begin in 2008. Various other choices for emission trading schemes have also been proposed. Uncertainty in emissions to be traded may be significant, and vary largely between different emission trading schemes. In this paper, we estimate the uncertainties in different emission trading schemes based on uncertainties in corresponding inventories. According to the results, uncertainty in emissions included in the EU emission trading scheme (2005-2007) from EU-15 and EU-25 is ±3% (at 95% confidence interval relative to the mean value). If the trading were extended to CH4 and N2O in addition to CO2, then tradable amount of emissions would increase only by 2%, but the uncertainty in the emissions would range from -4 to +7%. Finally, uncertainty in emissions included in the emission trading under the Kyoto Protocol was estimated to vary from -6 to +21%. Inclusion of removals from LULUCF activities under the Kyoto Protocol did not affect total uncertainty. The results including the LULUCF estimates should be considered only as indicative.