Regionalised inventory of biogenic greenhouse gas emissions from European agriculture

This study develops a detailed methodology compatible to the Guidelines of the Intergovernmental Panel on Climate Change (IPCC) to assess the annual direct biogenic emissions of greenhouse gases (GHG) released from European agriculture. This approach relies on emission factors and regression equations derived from all long-term measurements in Europe available by the end of 2001. Applying the methodology, the biogenic GHG emissions from agriculture within the European Union (EU) and within its Member States are calculated for the period from 1975 to 1997 at a spatial resolution of regions or federal states (NUTS 1-2 level). As a result, in 1995, European agriculture emitted 0.84+-0.19 Tg N2O, 8.1+-2.0 Tg CH4 and 39 Tg+-25 CO2, which adds up to 470+-80 Tg CO2-equivalents or 11% of the overall GHG emissions. At the EU level, these numbers are surprisingly close to the official inventory submitted under the United Nations Framework Convention on Climate Change (UNFCCC). But compared with the latter, the approach taken here leads to higher agricultural CH4 emissions in Austria and the Netherlands, at least 20% lower CH4 emissions in Denmark, Germany, Greece, Spain and Sweden and higher N2O emissions in most EU Member States. In countries with--even small--areas of farmed organic soils, CO2 emitted from peat oxidation can significantly contribute to the overall emissions. Hence, only the detailed approach adequately resolves regional and national specifics of agricultural conditions. It furthermore reduces the uncertainty in the emissions estimates to half of the one in inventories based on the IPCC Guidelines. Fair agreement with inverse atmospheric models was achieved. These results suggest that the methodology developed and applied here could serve as a significantly improved standard for official inventories of biogenic GHG emissions from EU Member States.