Uncertainties in the Finnish greenhouse gas emission inventory

Reliable uncertainty estimates are a tool for increasing the quality of national emission inventories which are essential for the implementation of the Kyoto Protocol. The first detailed uncertainty assessment was performed for the Finnish greenhouse gas emission inventory considering the years 1990 and 2001 using Monte Carlo simulation to combine uncertainties. In this work, uncertainty estimates were based on available measurement data, domestic and international literature, expert judgement and the recommendations of the Intergovernmental Panel on Climate Change (IPCC). Uncertainties were estimated at a more detailed level than in studies performed in many other countries, thus giving additional information on the most important emission sources in terms of uncertainty. The emissions of the most important greenhouse gas, CO₂, are often well known, but the other gases contain higher uncertainties. The resulting total uncertainty in the year 2001 emissions was −5 to +6% and that of trend ±5%-points. The uncertainty range indicates that Finnish emissions were 75–84 Mt CO₂ equivalents in 2001. In countries with larger emissions the effect of uncertainty is even more significant. Countries which have performed an uncertainty estimate are able to use the information on most uncertain sources in allocation of resources for inventory improvements. In climate policy, information on uncertainty can be used in negotiations on the use of Kyoto mechanisms and in negotiations of inclusion of new sources or gases in future climate conventions. Integration of uncertainty aspects in decision making ensures that climate conventions are of real benefit in terms of mitigating climate change.