Changes in tropospheric aerosol and reactive gases burdens and concentrations under IPCC-AR5 emission scenarios for 1850-2100
Résumé
Tropospheric ozone and aerosols are major climate forcing agents but the quantification of their forcings are still highly uncertain. In the framework of the ACC-MIP, a global decadal dataset describing the emissions of aerosols and ozone precursors and consistent with those provided for long-lived GHG, was made available. It allowed chemistry-climate models to simulate the evolution of short-lived GHG over the historical period (1850-2005) and for 4 future projections (Representative Concentration Pathways). This work describes the results obtained with the LMDz-INCA model using these state-of-the-art emissions and considering past and future climate change trajectories in a General Circulation Model. These concentrations are currently used as forcing by the two French Earth system models (IPSL-CM5 and CNRM-CM5) to simulate the climate evolution in the CMIP5 framework. The variability and trends of the concentrations along with their relevance will be discussed. In parallel to these projections considering the anthropogenic emissions changes, a short insight on the potential impact of natural isoprene emission changes on ozone will be shown.