Harmonisation of historical and future emission data for climate and air quality modelling

Climate change and air quality research are closely related research areas that have often been investigated with different objectives. However, addressing both topics as a joint approach can lead to synergies and help to avoid counteracting effects, where mitigating one may exacerbate the other. A convergence of methods and approaches is necessary to consider on the one hand the climate trend and forcing in mitigation scenarios applied by the air quality community and on the other hand to better understand and describe the impact of short-lived climate pollutants.

The project FOCI aims to analyse non-CO2 forcings on both climate and air quality and therefore requires a joint approach. The project applies regional climate and urban scale models driven by global earth system models to describe continental to urban scale air quality under present and future climate conditions.

The present and future anthropogenic emissions required for such model investigations need to be consistent with CMIP6 historical climate reconstruction and future scenario simulations. One critical aspect is that pollutants considered in CMPI6, which is based on CEDS, do not include particulate matter (PM2.5/PM10) but only its black and organic carbon (BC/OC) components. This would cause a significant underestimation of particulate matter concentrations and raises the need to define a method to estimate the non-speciated PM emissions from the available information.

In order to derive historical and future PM emissions consistent with CEDS we investigate a number of approaches based on the use of different proxies from the EDGAR database. These estimated datasets of consistent CEDS and particulate matter emissions are used in the FOCI project numerical models to describe continental to urban scale air quality under present climate conditions as well as for different SSP projections to ultimately evaluate the impact of key radiative forcers on climate and societal systems.