Future air quality in Europe: a multi-model assessment of projected exposure to ozone
1Institut National de l'Environnement Industriel et des Risques (INERIS), Verneuil-en-Halatte, France
2Université Paris 6 Pierre et Marie Curie, CNRS-INSU, LATMOS-IPSL, Paris, France
3NOAA Earth System Research Laboratory, Boulder, CO, USA
4Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
5Max Planck Institute for Meteorology, Hamburg, Germany
6Universitetet i Oslo (UiO), Oslo, Norway
7FRIUUK, Köln, Germany
8Institute of Atmospheric Sciences and Climate, Consiglio Nazionale Delle Ricerche, Bologna, Italy
9Meteorologisk institutt (met.no), Oslo, Norway
10International Institute for Applied Systems Analysis, Laxenburg, Austria
11ENEA, Bologna, Italy
12Laboratoire d'Aérologie, Toulouse, France
13Chalmers University of Technology, Gothenburg, Sweden
14Laboratoire des Sciences du Climat et de l'Environnement, IPSL, CEA, CNRS-INSU, UVSQ, Gif-sur-Yvette, France
*now at: Center for International Climate and Environmental Research-Oslo (CICERO), Oslo, Norway
Abstract. In order to explore future air quality in Europe at the 2030 horizon, two emission scenarios developed in the framework of the Global Energy Assessment including varying assumptions on climate and energy access policies are investigated with an ensemble of six regional and global atmospheric chemistry transport models.
A specific focus is given in the paper to the assessment of uncertainties and robustness of the projected changes in air quality. The present work relies on an ensemble of chemistry transport models giving insight into the model spread. Both regional and global scale models were involved, so that the ensemble benefits from medium-resolution approaches as well as global models that capture long-range transport. For each scenario a whole decade is modelled in order to gain statistical confidence in the results. A statistical downscaling approach is used to correct the distribution of the modelled projection. Last, the modelling experiment is related to a hind-cast study published earlier, where the performances of all participating models were extensively documented.
The analysis is presented in an exposure-based framework in order to discuss policy relevant changes. According to the emission projections, ozone precursors such as NOx will drop down to 30% to 50% of their current levels, depending on the scenario. As a result, annual mean O3 will slightly increase in NOx saturated areas but the overall O3 burden will decrease substantially. Exposure to detrimental O3 levels for health (SOMO35) will be reduced down to 45% to 70% of their current levels. And the fraction of stations where present-day exceedences of daily maximum O3 is higher than 120 μg m−3 more than 25 days per year will drop from 43% down to 2 to 8%.
We conclude that air pollution mitigation measures (present in both scenarios) are the main factors leading to the improvement, but an additional cobenefit of at least 40% (depending on the indicator) is brought about by the climate policy.