An integrated approach to climate change and regional air pollution can harvest considerable ancillary benefits in terms of environmental impacts and costs. This is because both problems are caused to a large extent by the same activity (fossil fuel combustion). Substantial ancillary benefits were found for regional air pollution (SO 2 , NO x , VOC and particulate matter) of implementing the Kyoto Protocol (intended to control greenhouse gas emissions) in Europe. For instance, while three different scenarios on Kyoto implementation were found to reduce European CO 2 emissions by 4-7%, they also reduced European emissions of SO 2 by 5-14% compared with a no Kyoto policies case. The magnitude of ancillary benefits depends on how flexible mechanisms and surplus emission allowances are used in meeting the Kyoto targets. The total cost savings for implementing current policies for regional air pollution of the Kyoto Protocol are of an order of 2.5-7 billion Euro. In all cases, this is in the order of half the costs of the climate policy (4-12 billion Euro). Using flexible mechanisms reduces emissions of air pollutants for Europe as a whole even further than domestic implementation (e.g. 10-14% versus 5% for SO 2 emissions), but the reductions are shifted from Western Europe to Central and Eastern Europe and Russia. The use of surplus emission allowances to achieve the Kyoto targets decreases the ancillary benefits, in particular for the latter group of countries (e.g. unprotected area against acidification increases from 1.3 to 1.7 million ha).

Now at Statens Forurensningstilsyn, Slrømsveien 96 Oslo, NorwayIn recent decades land-based emissions of air pollutants have been substantially reduced over Europe. At the same time emissions from shipping have continued to grow globally. Emissions from international shipping in sea areas surrounding Europe now contribute about 30% of the EU27 emissions of sulphur and NO x and affect ozone levels all over Europe. Although ozone levels are expected to decrease in most parts of Europe, prognoses for 2020 levels are still above what is considered as threshold values. A growing portion of these impacts can be attributed to emissions from international shipping.This paper presents an evaluation of the impacts on ozone levels in the European mainland due to emissions from international shipping. Calculations are carried out under recent (2004) conditions and for a scenario in 2020, where further emission reductions are applied to land based emissions while the ships emissions increase according to their expected growth in transport volumes, without additional technical reduction measures. Impacts are considered with respect to the formation of ground-level ozone, presented as somo35. We investigate the effect of different shipping emission sources, in particular, international shipping inside the 12 mile zone from the coast, emissions from ships outside the 12 mile zone with EU flags and emissions from ships under other flags. It is shown that contributions from EU ships and non-EU and ships outside the 12 mile zone are about equal in magnitude. Corrected for source strength, the largest effect relative to source strength is from emissions within the 12 mile zone. Here ozone titration may cause reductions in somo35 of more than 10% in some countries, or increases of 5% or more elsewhere.

PrefaceReliable knowledge of the sources and magnitudes of emissions of air pollutants is an absolute requirement for any assessment of air pollution for research and policy purposes .A few years ago, accessible information on pollution in many eastern European countries was sparse. Nevertheless, using IIASA's position as an East-West institute, IIASA's Transboundary Air Pollution Project developed the RAINS model for the integrated assessment of international strategies to reduce trans boundary air pollution in Europe. With the help of many collaborators in IIASA 's member countries, the databases have been filled with the best information available at that time .Now the situation has changed and environmental information is abundant. However, serious questions remain as to the quality and the international consistency of national data. Again, IIASA has used its scientific network to establish the first harmonized inventory of air pollutants' emissions in the region of the Central European Initiative. The task was facilitated by the fact that most countries participating in this new initiative are also members of IIASA.Providing detailed information on emissions in the heart of Europe this inventory will serve as a valuable basis for the design of effective strategies to reduce air pollution in Europe. Abstract-This paper presents the first consistent inventory of emission of sulphur dioxide (S0 2 ), nitrogen oxides (NO,), particulate matter (PM), and carbon dioxide (C0 2 ), for the countries co-operating in the Central European Initiative: Austria, Croatia, Czechoslovakia, Hungary, Italy, Poland and Slovenia. The inventory is based on national and regional statistics as well as on information received from collaborating institutions. National data has been verified and converted into a common format, consistent with the database used by the European Environmental Agency and the European Community (the "CORINAIR" system). The inventory describes emissions in the year 1988, before the restructuring process began in former socialist economies. Data has been collected on the national level, for administrational units and for large point sources. The database on point sources contains specific information on 400 large plants in the region (e.g. capacity, commissioning year, fuel use, production, etc.). Total emissions ofS0 2 in the CE! region in 1988 were 10.3 million tons, which accounts for 25 % of total European S0 2 emissions. The highest emission densities (more than 100 t km -2 ) are found in Northern Bohemia (Czech Republic) and Upper Silesia (Poland). The overwhelming majority ofS0 2 emissions (70%) originates from combustion of domestic (brown and hard) coal. Across the region, 60% of S0 2 is emitted from the large point sources identified in the study and over 50% ofS0 2 emissions from public power plants in the CEI region is produced in plants older than 20 years.