Projection of Air Quality in Melbourne, Australia in 2030 and 2070 Using a Dynamic Downscaling System

A multi-scale dynamical downscaling system has been set up to investigate future air quality trends in Melbourne, Australia due to climate and/or emission changes. The system consists of a comprehensive air emissions inventory; an ensemble of climate trends, a regional climate model for downscaling from synoptic to regional scale and a meteorological-chemical transport model for downscaling from regional to urban scale. Air quality projections for 2030 and 2070 suggest that, in the absence of emission controls, ozone concentrations will increase, leading to a 20-25 % increase in population exposure. The outcomes for PM2.5 show mixed results depending on season. The air quality trends with three different emission scenarios for 2030 were also modelled under the same climate projection. Some impact measures, such as average ozone concentration, are insensitive to the choice of emission scenarios, while others such as exposure to nitrogen dioxide show significant variations for different scenarios.