ABSTRACT
Over the last decades air quality and energy issues achieved considerable attention in the European Union (EU). European citizens and institutions constantly acknowledge the need to reach a sustainable pattern between human activities and the natural ecosystem. European environmental regulation is moving fast to comply with the increasing number of international agreements and domestic laws to reduce global emissions. Most of the air pollution problems affecting the EU have their effects at either local or transboundary scale. Acidification as well as ozone depletion and greenhouse gases (GHGs) are pollution problems which are of primary interest to European countries. In the case of acidification, the physical formation process, due to sulphur dioxide (SO2), nitrogen oxides (NO×) and ammonia (NH3), when released in the atmosphere and transformed to acids is deposited either via rain precipitation (wet depositions) or falls directly (dry depositions) on the Earth’s surface. Either ways the natural ecosystem is damaged. At the same time, these depositions, together with fine particles in the atmosphere, deplete the ozone layer. Primary precursors of acidification and ozone depletion are mostly generated from stationary sources (coal burning power plants, industrial boilers or agricultural activities in the case of NH3) and mobile sources such as vehicle emissions. The 1997 European Commission staff working paper on acidification (European Commission, 1997a) showed that although progress has been made in the short term, the long-term strategy of ‘no exceeding ever of critical loads and levels’ of the Fifth Environmental Action Programme appears difficult to achieve. The main effect of the acid depositions varies spatially, depending on the sensitivity of the receptors. Critical loads reflect the sensitivity of a certain ecosystem by defining the exposure to pollution that each ecosystem can tolerate before damage occurs. Among European countries, sensitivity varies across different areas. For example, northern EU countries suffer high-sensitivity levels to acid depositions. Nevertheless, even if reduction in acidification takes place, acidification itself will not
stop damaging the natural ecosystem until depositions would reduce below critical load thresholds. The critical load approach has been implemented as a tool to carry out effect-based and cost-effectiveness abatement strategies under the Convention on Long Range Transboundary Air Pollution (CLRTAP) (United Nations, 1979). The approach was also used to negotiate the 1994 Sulphur Protocol (United Nations Economic Commission for Europe, 1994). More recently, a Framework of Air Quality Directives (European Commission, 1996a) entered into force to reduce, among other things, SO2, particulate and ozone depletion. The Council conclusion in 1997 recognised the impossibility of achieving the long-term target for the whole of Europe by 2010. By using a gap-closure methodology, various interim targets are available, whose aim is a rational approach to closing the gap between the ecosystem-level protection in 1990 and the 100 per cent protection by a given percentage. However, with current available technology a 50 per cent gap closure target should be achieved by 2010. Long-term targets of acidification reductions are also carried out by an international system of agreed data on emissions, transboundary fluxes and budgets depositions. These have been developed and constantly updated by the International Institute for Applied Systems Analysis (IIASA)1 and the European Monitoring and Evaluation Programme (EMEP).2 On the basis of these tools, the community adopted national emission ceilings (NECs), through Daughter Directives (European Commission, 1999a, 2000a, 2002a and 2005a) consistent with the approach undertaken by the United Nations Economic Commission for Europe (UNECE) Convention on Long Range Transboundary Air Pollution (CLRTAP) (United Nations, 1979). NECs allow for a certain degree of flexibility for Member States to determine the most cost-effective way to decide on pollution emission thresholds. In the context of air pollution, the Large Combustion Plant Directive (LCPD) (European Commission, 2001a) merits particular attention. The LCPD aims to reduce the emission levels of acidifying pollutants and fine particles from large combustion plants contributing to achieve the targets of the CLRTAP and the NECs. Also, the LCPD sets more stringent emission limit values for combustion plants above 50 Megawatt (MW) thermal which are built since 1987 and 2002. For pre-1987 plants, on the other hand, the LCPD gives the opportunity to Member States to opt for either applying the new emission values or developing a National Plan to reduce emissions; in the case of a National Plan for SO2 and NO× this would aim at reducing total annual emissions by the year 2012 to emission levels that would be achieved by applying the existing plant during 2000. However, the EU only sets limit values of SO2 and NO× leaving countries the freedom to choose the appropriate environmental regulation tool to achieve emission targets.
