An Updated Set of Scenarios of Cost-effective Emission Reductions for the Revision of the Gothenburg Protocol

The Convention on Long-range Transboundary Air Pollution has started negotiations on the revision of its Gothenburg multi-pollutant/multi-effect protocol. To inform negotiations about the scope for further cost-effective measures, the EMEP Centre for Integrated Assessment Modelling (CIAM) has presented to the 48th Session of the Working Group on Strategies and Review a series of emission control scenarios that illustrate options for cost-effective improvements of air quality in Europe (Amann et al., 2011). After review of these initial calculations, 24 Parties have provided updated information on their national emission inventories and projections to CIAM. This report presents updated emission control scenarios that would achieve the environmental targets laid out in the CIAM 1/2011 report, taking into account this new information. In general, the analysis with the updated information confirms - at an aggregated level - the cost-effective allocation of measures that has been presented in the earlier report. However, for a few countries, scenarios and pollutants, changes are significant. The report suggests a substantial scope for further environmental improvement through additional technical emission reduction measures. Cost-effective emission control scenarios are presented for five different sets of environmental targets on air quality. These targets cover a range from 25% to 75% of the feasible improvements for each effect, and they involve additional emission control costs between 0.6 and 10.6 billion Euros/year over the entire modelling domain (on top of the costs of the baseline scenario). Between 50 and 60% of costs emerge for the EU-countries. However, since the EU-27 includes 72% of total population and 88% of GDP in the modelling domain, these scenarios imply higher relative efforts for some non-EU countries. A substantial share of the environmental improvements could be achieved with a limited set of measures. A comparison with the national activity projections reveals that the emission ceilings that have been optimized for the Europe-wide (PRIMES/CAPRI) activity projections are, with very few exceptions, within the emission ranges that could be achieved for the national activity projections. Potential conflicts occur only for countries where national projections employ fundamentally different assumptions on the future development in the various sectors. Negotiations on national emission ceilings should consider, in addition to the cost-effective sets of national emission caps outlined in this report, uncertainties and systematic differences in the base year inventories reported by Parties, especially if they rely on different sources of statistical information and include different source categories.