An investigation into the climate change mitigation potential of road transport emissions in eThekwini Municipality.

Abstract

The South African transport sector as a whole is the second largest source of green house gas (GHG) emissions, with South Africa’s road transport sector contributing 80-90% of the total transport emissions. As such there is a need to estimate and assess the contribution and implications of emissions from the road transport sector for both ambient air quality and climate change. This justifies the need for a coherent a holistic vehicle emission modelling framework and scenario analysis for the management of co-emitted emissions in urban areas. The eThekwini Municipality has been progressive in terms of addressing climate change. However, ambient air quality data indicates that road transport is an increasing source of emissions in the municipality. Previous studies of road transport in the municipality have failed to account for off-road transport and therefore over-estimate emissions from on-road vehicles. Furthermore, little work, to date, has been carried out in terms of understanding the mitigation potential of different interventions that could be implemented in the road transport sector. As such the main aim of this study was to compile a baseline emission inventory for the road transport sector for the municipality that could be used to assess the local applicability of potential mitigation measures that have been previously investigated at a national level. These interventions were then prioritised in terms of ability to contribute towards reducing air pollution. The Computer Programme to Calculate Emissions from Road Transport (COPERT) IV model was used to compile an inventory for the municipality based on the on and off road eNATIS vehicle database. The analysis revealed that passenger vehicles and HCV’s produced the greatest quantities of emissions, with diesel engine vehicles responsible for more of the emissions. This baseline was then used to investigate interventions that would simultaneously reduce emissions in the road transport sector. This study found that the most suitable measures include the use of improved efficiency petrol and diesel internal combustion engines, biofuels, shifting freight from road to rail and shifting passengers from cars to public transport (reduced vehicle kilometres and modal shift). By employing these proposed mitigation measures, simultaneous reductions of air quality and climate change emissions can be achieved.