Sammanfattning
In order to investigate the effects of climate change on air quality in Europe, we have utilised the regional CTM (chemistry and transport model) MATCH, forced by meteorology representing future climate conditions but keeping the emissions at their current value. The meteorology is from RCA3, the Rossby Center’s regional climate model (covering all Europe on 50 km × 50 km resolution). RCA3 is, in the current study, run under the SRES A2 emission scenario forced with corresponding climate data from ECHAM4/OPYC3 global model on its boundaries. We have applied our CTM on three different 30-year periods representing current, near- and distant future climate (1961-1990, 2021-2050 and 2071-2100, respectively). Detailed description and validation of the climate model and the CTM is given elsewhere. In the present report we report seasonally-averaged changes in near-surface ozone, secondary inorganic aerosols (SIA) and deposition of sulphur and nitrogen containing species in Europe. The seasonal-mean ozone concentrations are expected to increase considerably (1-2% per decade up to 2050) in central and southern Europe, in particular during summer. The daily maximum concentrations are expected to increase even more than the daily mean concentrations. Northernmost Europe is projected to experience lower ozone concentrations under future climate, especially during spring and autumn. The concentration of SIA will increase dramatically in continental Europe during all seasons except winter. The increase is largest around the Mediterranean during summer. The average summertime concentration of SIA will be 20% higher in 2021-2050 and 50% higher in 2071-2100 compared to current levels as a result of changing the meteorology (drier and warmer conditions in central and southern Europe). The increase in atmospheric SIA concentrations is related to the large decrease in wet deposition of sulphur- and nitrogen containing species, which will be the consequence of climate change in large parts of central and southern Europe. Large areas around the Mediterranean, France, Belgium and the Netherlands will receive 50%, or less, of current nitrogen- and sulphur deposition in 2071-2100 compared to present conditions. The Norwegian coast, on the other hand, is expected to receive more sulphur- and nitrogen deposition due to the anticipated increase in precipitation in this area.