TOWARDS THE REGULATION OF NON-ROAD DIESEL EMISSIONS IN AUSTRALIA - A NATIONAL IMPACT PATHWAY MODEL.

In 2018, around 640,000 non-road diesel engines (NRDEs) were in use in Australia, with a projected stock of one million units by the mid-2040s. There are no Australian regulations to limit emissions from NRDEs, and Australia has not fully benefitted from legislation elsewhere. All engines (and equipment) are imported, but the uptake of the most recent technologies has been low. The locations of NRDEs in Australia and their patterns of activity are also poorly understood. This analysis involved the development of a whole-of-Australia impact pathway modelling approach for NRDEs, focussing on PM2.5 and NO2. It defined the NRDE stock and spatial distributions of emissions, air quality and health outcomes in a business-as-usual (BAU) scenario for the period 2018 to 2063, as well as three emission management scenarios. The NONROAD model formed the basis of a bottom-up calculation of emissions for the scenarios. This covered 27 equipment types, with a breakdown by power, emission standard and age. The bottom-up results were calibrated using ABS diesel statistics, and various methods were employed to allocate emissions spatially. The CSIRO Chemical Transport Model (C-CTM) was then used to simulate air pollution across Australia without NRDEs. The C-CTM predictions were refined using satellite land-use regression, followed by perturbation for NRDE emissions. The impacts of the NRDE perturbation on health - as years of life lost (YLL) - were estimated using a life table approach, including a cessation lag structure. In 2018 NRDEs were responsible for up to 15% of anthropogenic NOX emissions, and up to 5% of anthropogenic PM2.5 emissions in Australia. The annual YLL for NRDE-related NO2 and PM2.5 concentrations equated to around 9% of the total YLL for all anthropogenic NO2 and PM2.5. Over the full time period of the analysis, the management scenarios reduced YLL by between 6% and 27%. [ABSTRACT FROM AUTHOR]