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Explora: Environment
and Resource WTW emissions of road and rail transport

unused potential in Australia, since (non-bulk) freight is around 75 – 175 g CO -e/tkm (ICEV), 5 – 180 CO -e/tkm
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currently dominated by road. This study suggests that the (BEV), and 12 – 110 CO -e/tkm (FCEV). The road freight
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electrification of rail freight should be seriously considered WTW EIs from this study fell within the reported LCA
from an environmental and climate change (emission range (5 – 210 CO -e/ tkm) in the IPCC report.
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reduction) perspective, although it is acknowledged that The mean emission intensity for diesel rail freight
existing barriers would also need to be addressed. For from this study varied between 26 and 27 g CO -e/tkm.
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instance, other research 32,33 has reported on steam-age The LCA emission intensity for diesel rail freight from the
(slow speed) railway track alignments and additional travel IPCC study was between around 10 and 70 g CO -e/tkm.
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distances/times due to long and winding routes. The diesel rail freight WTW EIs of this study fell within the
A previous study estimated total WTW emissions reported LCA range in the IPCC report.
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from the Australian road transport sector to be 104 Mt
CO -e in 2019 and about 60 Mt CO -e in 2050. The results 3.4. Transport mode shift tool
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in Table 7 indicate that two-way road passenger transport The outcomes from this study have been used to create a
between Brisbane and Melbourne would represent a transport mode shift tool, which is available free of charge
small contribution (<1%) of total national road transport for non-commercial purposes. The tool estimates the
emissions. Freight transport on the route would represent average GHG emissions performance, expressed as either g
a smaller percentage of national road transport emissions CO -e/ pkm (passenger transport) or g CO -e/tkm (freight
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(0.3% in 2019 and 0.5% in 2050). However, the impact of transport) for different transport mode mixes. The tool can be
mode shift on total emissions would substantially increase run in deterministic or stochastic mode and estimates mean
were other intercity and intracity routes to be considered. and median performance values, as well as plausible ranges.
3.3. Comparison with international studies 4. Other aspects and future work
Comparing the EIs from this study with others in the Modeling of the emissions impacts of multi-transport
international scientific literature is not straightforward, on mode shift has, by its nature, a wide scope and requires the
account of methodological differences and factors such as consideration of a broad range of inputs and information.
the years being studied, the composition of the fleet, the The scope of the present study can be expanded in future
fuel mix, and, crucially, the emission intensity of electricity research. For instance, a broader range of transport
generation (especially in future years). Unsurprisingly routes, additional scenarios, and transport modes could
therefore, the literature contains a wide range of results, be considered, also integrating the economic and social
and high-level comparisons for current years are likely to aspects of mode shift. This would provide a more holistic
be the most appropriate. understanding of modal shift strategies.
For example, the mean 2019 WTW emission intensity Similarly, expansion from WTW to LCA would be
for road passenger transport from this study was 138 g of great interest, and could include, for instance, the
CO -e/pkm. This was similar to the global average value of emissions associated with the construction of new rail
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132 for large cars and non-urban travel in 2019 from the infrastructure. It will also be of significant interest to
International Energy Agency (IEA). However, the IEA conduct a further in-depth and extensive review of the
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values ranged from 61 to 322 g CO -e/pkm. The mean 2019 international scientific literature review and compare the
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emission intensity for rail passenger transport from this study outcomes from the review with the results of this study.
was 36 g CO -e/pkm, which was higher than the IEA average
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value of 14 but well within the reported range (6 – 118). Although it was beyond the scope of this paper,
the probabilistic approach can be used to quantify the
The IEA does not publish corresponding statistics importance of the model input variables on the simulation
for freight transport, and for WTW emissions, there outputs. This can be done through a sensitivity analysis
does not appear to be any other comprehensive review. and is recommended for future work.
However, a summary of LCA EIs (excluding infrastructure
construction and maintenance) was given by the There is a lack of extensive and detailed data for rail
Intergovernmental Panel on Climate Change (IPCC). operations in Australia, including train weight, occupancy
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Concerning road freight, the mean WTW EIs from this and load, as well as real-world energy consumption and
study were 49 g CO -e/tkm (2019) and 30 g CO -e/tkm emission data for diesel locomotives. This is a notable
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(2050), and these represented a mix of ICEV, BEV, and source of uncertainty in the models.
FCEV. Although not directly comparable, IPCC gave a The work presented here could be refined and extended
range of LCA values for heavy trucks (50% payload) of in several ways, including, for example:

Volume 1 Issue 1 (2024) 14 doi: 10.36922/eer.3470