European in 2050, a regional air quality and climate perspective

The impacts of climate policies on air quality are twofold. First, climate policies imply energy efficiency measures and other technical measures that will have an impact on a wide range of human activities, emissions, and, in turn, on air quality. Second, air quality is sensitive to climate change (which affects physical and chemical properties of the atmosphere) and long range transport of background pollution. Measures designed to mitigate climate change and their effectiveness will thus have both direct and indirect impacts on air pollution. To quantify changes in air pollution in Europe resulting from climate policies at the 2050 horizon, we designed a comprehensive modelling system that captures the external factors considered to be most important for air quality and which relies on the latest set of air pollution and climate scenarios. Climate simulations rely on the recent Representative Concentrations Pathways (RCP) of IPCC whereas air quality modelling is based on the emissions produced in the framework of the more recent Global Energy Assessment. The results are presented in terms of indicators that are relevant regarding the impact of air pollution on health. Furthermore attention is given to the de-convolution of the respective contribution of changes in European emissions, hemispheric background concentrations and climate conditions. A specific focus is devoted to the analysis of switching from a meteorological reanalysis to a regional climate model when driving the air quality simulations. The uncertainty brought about by the climate model over the control period is quantified and perspectives to narrow such uncertainties are discussed