According to a recent study, short sea shipping produces one fifth of the carbon emissions (well-to-wheel) of road freight. Rail also performed well, accounting for about a quarter of emissions from freight transport.
Despite this, freight transport accounts for nearly 80% of New Zealand’s heavy goods transport and 94.5% of total heavy goods transport emissions.
The dominance of freight transport follows the expansion of the road network, which allows trucks to travel relatively quickly, travel to hard-to-reach locations, and adjust routes to meet the flexibility needed for just-in-time deliveries.
Transport dashboard, CC BY-ND
But despite its benefits, freight transport is associated with external costs, including higher carbon emissions than other modes of transport.
This study represents the most comprehensive comparison of freight emissions across carriers to date for Aotearoa, New Zealand.
Before we evaluate the decarbonization pathways, we need to have a good understanding of the cargo system. We have one for this transport dashboard to visualize the carbon footprint of freight movements within New Zealand.

Transport dashboard, CC BY-ND
Firmly anchored with decarbonisation obligations legislation, we have hard deadlines to reduce emissions. Failure to do so puts New Zealand’s economy at risk and is likely to require taxpayer money to purchase expensive international goods carbon offsets.
Read more: Why New Zealand needs to invest in smart rail ahead of green hydrogen to decarbonise transport
We need to rethink the way we work
A shift to less energy-intensive freight transport modes such as short sea shipping and rail is one possible way to reduce dependence on fossil fuels.
But despite the benefits of maritime and rail transport, it remains unclear how to achieve the shift to new infrastructure and technologies. An important requirement is access to an efficient multimodal network that integrates ports, inland terminals, distribution centres, roads and railways.

Transport dashboard, CC BY-ND
We can reach economies of scale by transporting larger quantities of goods, which would lead to a lower cost per unit. as the European Commission noted:
The challenge is to bring about structural changes so that rail can compete effectively and carry a significantly larger share of medium and long-distance freight traffic.
Our research aimed to gain a detailed understanding of New Zealand’s current heavy freight system. Emissions reporting extended beyond the direct combustion of fuels and included in-vehicle emissions. We also consolidated data from multiple sources, which helped calculate energy demand and direct and indirect emissions for each cargo mode.
For example, we found that the majority of a truck’s lifetime emissions (almost 80%) come from the fuel it consumes. That is why it is important to prioritize operational aspects and move to non-fossil propulsion technologies.
Read more: Transport emissions have doubled in 40 years – expand the railways to get them on track
Where to from here
Significant investments will be required to expand or improve transport networks optimizing freight corridors in terms of energy consumption and emissions. In addition to our research, we need additional work to investigate the technical and economic feasibility of non-fossil propulsion technologies.
We’ll have to take one holistic approach to identify feasibility hurdles (technical challenges, material needs, system architecture and integration) to be overcome.
The ultimate goal is to reduce fossil fuel demand and emissions while ensuring long-term economic and trade resilience.
Equally crucial is stakeholder participation and support. Freight transport is a complex system characterized by multiple interests (policy makers, shippers, forwarders, port and rail representatives) with sometimes conflicting views. Strategic planning must also take into account consumer preferences and their implications energy consumption.
The last report by the Intergovernmental Panel on Climate Change (IPCC) explains this:
Drawing from diverse knowledge and cultural values, meaningful participation and inclusive engagement processes – including indigenous knowledge, local knowledge and scientific knowledge – facilitates climate-resilient development, builds capacity and enables locally appropriate and socially acceptable solutions.
In addition to the focus on emission reductions, we need to develop cargo systems with a high adaptability, so they can support trade and wellness while operating at much lower energy levels. The concept of adaptation must also extend beyond the current focus on physical protection against extreme weather conditions.
Read more: IPCC report: The world must reduce emissions and urgently adapt to the new climate reality
The tools and technologies to decarbonise freight transport in New Zealand are now available. The problem lies in their integration and understanding the tradeoffs at stake. Emissions from freight transport can be reduced through cost-effective investments in multimodal infrastructure and alternative propulsion technologies.
However, it is essential for future initiatives to operate within the biophysical boundaries of our planet, as highlighted in the IPCC report:
Technological innovation can bring trade-offs, such as new and greater environmental impacts, social inequalities, over-dependence on foreign knowledge and suppliers, distributional and rebound effects, which require appropriate governance and policies to increase potential and reduce trade-offs.