MAQUIS · Mediterranean Air QUality In future climate Scenarios

Mediterranean Air QUality In future climate Scenarios

The Mediterranean basin is one of the regions of the world where significant impacts due to climate changes are predicted to occur in the future. Observations and model simulations are used to provide to the policy makers scientifically based estimates of the necessity to adjust national emission reductions needed to achieve air quality objectives in the context of a changing climate, which is not only driven by GHGs, but also by ozone and aerosols (short lived climate pollutants). Thus there is also an increasing interest to design cost-benefit emission reduction strategies, which could both improve regional air quality and global climate change. The project “Mediterranean Air QUality In future climate Scenarios” (MAQUIS, http://projectmaquis.org) improves the understanding of air quality-climate interactions in Europe, zooming on the Eastern Mediterranean region. In the first two years of the project we used the WRF-CMAQ air quality modeling system to quantify the contribution of anthropogenic emissions to ozone and particulate matter concentrations and to understand how this contribution could change for different future emission scenarios. Model simulations require emission fields at a specific grid resolution and projection and with hourly time resolution. A set of algorithms was developed to process total annual anthropogenic emissions, to obtain model-ready emission files spatially, temporally and vertically distributed, taking into account the different emission sources and country specific profiles. We have investigated four different emission scenarios for year 2050 defined by the EU FP7 CIRCE project: a “business as usual” scenario where no or just actual measures are taken into account; an “air quality” scenario (BAP) which implements the National Emission Ceiling directive 2001/81/EC member states of the European Union (EU-27); a “climate change” scenario (CC) which implements global climate policies decoupled from air pollution policies; and an “integrated air quality and climate policy” scenario (CAP) which explores the co-benefit of global climate and EU-27 air pollution policies. In the first phase of the project we estimated the impact of future emission scenarios keeping fixed the effect of meteorology on air quality. The BAP scenario largely decreases summer ozone concentrations over almost the entire continent, while the CC and CAP scenarios similarly determine lower decreases in summer ozone but extending all over the Mediterranean, the Middle East countries and Russia. Similar patterns are found for winter PM concentrations; BAP scenario improves pollution levels only in the Western EU countries, and the CAP scenario determines the largest PM reductions over the entire continent and the Mediterranean basin. In the second phase of the project we performed 5-year winter and summer monthly simulations for present climate 2008-2012, and two future climate scenarios 2048-2052 downscaling global climate model output from RCP4.5 and RCP8.5 IPCC AR5 scenarios. We estimated warmer winters by 1-6 degrees over the entire continent, except for western Russia and Siberia, where slightly colder (than present) conditions, with slightly warmer winters in RCP8.5 compared to RCP4.5. Temperature anomaly pattern in July features warming in Western Europe and eastern Siberia, while in southern Europe we did not see a significant change in temperature compared to 2008-2012. The BAU and BAP emission scenarios were simulated in combination with RCP8.5 climate conditions, while the CC and CAP emission scenarios in combination with RCP4.5 climate conditions. Ozone concentrations in a BAU world increase over the entire European continent, with largest increases over North Western Europe in summer. The air quality policy implemented by the EU27 countries (BAP) benefits in particular the Mediterranean region, with decreasing summer ozone concentrations compared to the present climate conditions, while the situation is slightly improving in North Western Europe compared to BAU scenario, but with increasing summer ozone concentrations compared to present climate conditions. Under CC and CAP scenario we estimated similar summer ozone reductions compared to present conditions over the entire continent. The strong NOx emission reductions in the scenarios BAP, CAP and CC determine an increase in winter ozone concentrations. PM2.5 concentrations are significantly reduced by the air quality policy over the EU27 countries applied in the scenarios BAP and CAP. In winter large reductions were estimated in particular in the Po Valley in Italy and in Northern France, while in summer PM2.5 reductions are significant over Central and Eastern Europe, the Balkan Peninsula and Eastern Mediterranean. We are currently completing two sensitivity analysis using the CMAQ-Adjoint model to evaluate the ozone exposure on crop yield over Europe for the growing season (i.e., May-Aug) in 2014. This is the first time where adjoint method is used over Europe to estimate crop yield loss sensitivity. A second adjoint sensitivity analysis for the same episode is already planned to estimate the impact of changing temperature (climate penalty) on human health through the changes in surface O3 concentrations. Further informations are available in the MAQUIS website http://projectmaquis.org.

Data: CORDIS, © European Union