9.1 Methodology and Trends

9.2 NOx Emissions

9.3 CO Emissions

9.4 NMVOCs Emissions

9.5 SOx Emissions

9.1 Methodology and Trends

The emissions of GHG-precursors are also accounted in the Bulgarian GHG inventories. These gases have indirect influence over the greenhouse effect and should be included in the inventory aggregated to sectoral and national level. The emissions of SOx are accounted for, too. The sulphur oxide is not a greenhouse gas, but due to its importance and its effect on climate, it is included in the IPCC methodology and is reported in the CRF tables. Unlike the GHGs, sulphur oxides have negative effect on climate, i.e. the SOx emission cause cooling and their action is not global, but only regional.

The emissions factors for GHG-precursors (CO, NOx, NMVOCs) and SOx are determined based on country specific data, as well as on data from the IPCC Guidelines.

Figure 9.1 presents the emission trends for GHG-precursors and SOx.

As seen in Figure 9.1 during the period 1988 - 2000 there was a trend toward decrease of the emissions of GHG-precursors and SO₂. This trend displayed slight variations within the period with small growths in certain years. Such a growth was registered in the year 2001 for the NOx and SOx emissions. In 2002 an increase of the CO and reduction of the SOx emissions was observed.

The emissions of GHG-precursors and SOx are reported only for Energy and Industrial Processes sectors in the Bulgarian inventories. In Solvent and Other Product Use are released only emissions of NMVOCs. In the Field Burning of Agricultural Residues category of the Agricultural sector are emitted NOx and CO which are also accounted.