Emissions of the main ground-level ozone precursor pollutants have decreased across the EEA-33 region between 1990 and 2011; nitrogen oxides (NO X ) by 44%, non-methane volatile organic compounds (NMVOC) by 57%, carbon monoxide (CO) by 61%, and methane (CH 4 ) by 29%.
This decrease has been achieved mainly as a result of the introduction of catalytic converters for vehicles, which has significantly reduced emissions of NO X and CO from the road transport sector, the main source of ozone precursor emissions.
The EU-28 as a whole reported 2011 emissions at 4% below the 2010 NECD ceiling for NO X , one of the two ozone precursors (NO X and NMVOC) for which emission limits exist under the EU's NEC Directive (NECD). Total NMVOC emissions in the EU-28 were 22% below the 2010 NECD limit in 2011, however, seven of individual Member States did not meet their ceilings for one or both of these two pollutants.
Of the three non-EU countries having emission ceilings for 2010 set under the UNECE/CLRTAP Gothenburg protocol (Liechtenstein, Norway and Switzerland), all reported NMVOC emissions in 2011 that were lower than their respective ceilings, however Liechtenstein and Norway reported 2011 NO X emissions higher than their ceiling for 2010.
Data and maps
Emissions of ozone precursors