Estimation of country contributions to the climate change. Viewpoints of radiative forcing and uncertainty of emissions

Global warming that occurs due to emissions from a country or a country group was studied from two different points of view. Firstly, warming effect caused by Finnish emissions from 1900 to 2100 was assessed using a model that describes removal of greenhouse gases from the atmosphere by pulse response functions, and calculates the radiative forcing caused by an increase in atmospheric concentration. Secondly, Finland's share of global emissions was assessed for the time period during which detailed greenhouse gas inventories were available, i.e. from 1990 to 2003, taking into account uncertainties in emission estimates. The uncertainty estimate was made using literature, measurement data and expert judgement on input parameter uncertainties. Stochastic simulation was used to combine the uncertainties. In addition, uncertainties in different emissions trading schemes were compared at EU level. Greenhouse gases covered by the study were those included in the Kyoto Protocol, i.e. carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), perfluorocarbons (PFCs), hydrofluorocarbons (HFCs) and sulphur hexafluoride (SF6). Sectors covered were energy, industry, transportation, agriculture and waste. LULUCF sectors (land-use, land use change and forestry) were covered more superficially. Finnish greenhouse gas emissions in 2003 were 86 Tg CO2 eq (without LULUCF). According to the results, 95% confidence interval of this figure lies between 82 and 92 Tg CO2 eq. This represents a share of 0.2–0.3% of global emissions. In the same year, Finland's share of global population was 0.1% and share of global GDP 0.4%. The most important contributors to uncertainty were N2O emissions from agricultural soils, N2O from nitric acid production and CH4 from landfills. Inclusion of LULUCF categories in the inventory increased relative uncertainty of net emissions notably (emissions in 2003 were 68 Tg CO2 eq with a 95% confidence interval of 58 to 78 Tg CO2 eq).