Global Air Quality Predictions of Particulate Matter in the Middle East and Sensitivity to Future Emissions Scenarios

Abstract:

We examine the influence of natural and anthropogenic drivers of future PM in the Middle East region using two future emissions scenarios to drive the GEOS-Chem atmospheric chemistry model.  The Arabian Peninsula is a major source of windblown dust as well as anthropogenic aerosols. Future emissions – driven jointly and individually by climate change and anthropogenic emissions from this rapidly growing region – will play an important role in both climate forcing and human health impacts from particulate matter. We use two scenarios to compare their climate and air quality implications. First, we use the Intergovernmental Panel on Climate Change Representative Concentration Pathways (RCPs) for four radiative forcing cases. Second, we develop a consistent future greenhouse gas and conventional pollutant emission inventory using the MIT Emissions Prediction and Policy Analysis (EPPA) model, which is a general equilibrium model of the global economy that calculates how economic growth and anthropogenic emissions change as a result of policies and other stressors. With EPPA, we examine three emissions cases, a business-as-usual case and two stabilization cases leading to anthropogenic radiative forcings of 3.7 W/m² and 4.5 W/m². We use these scenarios to drive GEOS-Chem for present and future climate, assessing changes in chemical composition of aerosol and drivers, both natural and anthropogenic, out to 2050. We find that projected anthropogenic emissions are strong determinants of future particulate matter air quality in the Middle East region.