2. Nitrogen Oxides NOx

2. NITROGEN OXIDES - NO_x

2.1 NO_x-emissions by countries

The 1990 annual total NO_x-emissions for EUROPE were estimated to be 18 million tonnes as NO₂. These emissions broken down by EU-12, EFTA-5 and PHARE-10 countries are shown in figure 2.1. The largest contributor were the EU-12 countries with 67%, second largest the PHARE-10 countries with 22%; the EFTA-5 countries contributed 7% and Germany (former East), Croatia and Malta 4%.

Figure 2.1: Contribution in % to the European total NO_x-emissions

Figure 2.2 shows the relative contribution of individual countries to the total of 18 million tonnes. In 1990 the largest contributing countries were the United Kingdom (15%), Germany (former West; 13%) and Italy (11%); the smallest contributing countries were Malta (0.06%), Luxembourg (0.1%), Slovenia (0.3%) and Estonia (0.4%). These differences are due to different size of population and different per capita emissions (see also paragraph 2.3).

Figure 2.2: Contribution in % of each country to the EUROPEAN total NOx-emissions

2.2 NO_x-emissions per group

More than fifty percent of the NO_x-emissions for EUROPE in 1990 were produced by road transport (group 7) and other mobile sources and machinery (group 8). Forty percent of the NO_x-emissions for EUROPE resulted from emissions of group 1 (public power, cogeneration and district heating), group 2 (commercial, institutional and residential combustion) and group 3 (industrial combustion) together. Group 7 contributed the largest share with 44%, groups 1, 3 and 8 were the groups with the next largest contribution of 21, 14 and 13%. The remaining 8% of the total emissions can be attributed to emissions of the group 2 (commercial, institutional and residential combustion), group 4 (production processes) and group 9 (waste treatment and disposal).

The split of the NO_x-emissions into groups for EU-12, EFTA-5 and PHARE-10 countries is quite similar compared to the split for EUROPE with the exception of the relative large contribution of group 1 with 32% and a relative small contribution of group 7 with 22% for the PHARE-10 countries and a larger contribution of group 8 with 22% for the EFTA-5 countries (see figure 2.3).

The differences of contributions of the main source groups 7, 1, 3, and 8 to the total emissions are larger between countries than these groups (see also table 2.1). The contribution of group 7 in the countries ranges from 68% (Austria) to 9% (Romania), of group 1 from 42% (Czech Republic) to 0.4% (Norway), group 3 from 47% (Luxembourg) to nearly 0.4% (Greece) and group 8 from 50% (Norway) to 2% (Belgium, Wallonie region).

It is intended to explain these significant differences in a special NO_x-report. However it is evident from these differences in the relative contribution of source groups to a countries total emissions that strategies for reduction of NO_x-emission will need individual solutions as well as common elements.

Figure 2.3: Contribution in % of source groups to the European NO_x-emissions

2.3 NO_x-emissions per capita

Only anthropogenic emissions are expected to be related to population for these calculations. Therefore group 11 (nature) has been excluded.

For EUROPE the average NO_x-emissions per capita were 37 kg/capita. Compared to this number the per capita NO_x-emissions were only little larger for the EFTA-5 countries with 39 kg/capita, equal for the EU-12 and PHARE-10 countries with 37 kg/capita. This comparison is also shown in figure 2.4 and table 9.

Again the differences are much larger if individual countries are compared; the largest NO_x-emissions per capita were estimated for the Czech Republic (75 kg/capita) and the next largest ones for Luxembourg (61 kg/capita), Norway (55 kg/capita) and Finland and Greece (each 54 kg/capita); the smallest per capita emissions for NO_x were calculated for Hungary (18 kg/capita), Portugal and Croatia each (21 kg/capita), Romania (24 kg/capita) and Switzerland (25 kg/capita). Figure 2.5 shows the countries ranked according their per capita emissions. The already mentioned special report for NO_x will analyse these differences in the per capita emissions for NO_x, the smallest per capita emissions being almost a factor of 4 smaller compared to the largest number.

Figure 2.4: NO_x-emissions per capita for EUROPE

Figure 2.5: NO_x-emissions per capita for individual countries

2.4 NO_x-emissions per km²

The emissions per km² have been calculated from the total emissions, the emissions of group 11 (nature) having been included in this case.

For EUROPE the average NO_x-emissions per km² were estimated as 3 807 kg/km². Compared to this number the per km² NO_x-emissions were 3% smaller for the PHARE-10 countries with 3 677 kg/km², 42% larger for the EU-12 countries with
5 396 kg/km² and 74% smaller for the EFTA-5 countries with 1 000 kg/km². This comparison is also shown in figure 2.6 and table 10.

Figure 2.6: NO_x-emissions per km² for EUROPE

Again the differences are much larger if individual countries are compared: the largest NO_x-emissions per km² were for the Malta (36 614 kg/km²) and the next largest ones for Netherlands (13 887 kg/km²) and Belgium, Flemish region (13 439 kg/km²); the smallest emissions per km² for NO_x were for Norway (717 kg/km²), Sweden (767 kg/km²) and Finland (794 kg/km²). Figure 2.7 shows the countries ranked according their NO_x-emission per km². The differences in the emissions per km² between countries are much larger compared to the per capita emissions. The smallest number being 51 times smaller than the largest number.

Figure 2.7: NO_x-emissions per km² for individual countries

Table 2.1: Nitrogen oxides emissions per country and group