## 5 A Roadmap to Decarbonise Seaports  
The case studies in the previous section have different characteristics, e.g., the Port of Felixstowe is mainly a container port; the Port of Milford Haven is mainly an energy port; the Port of London's vast majority of carbon emissions are from various types of vessels; the ports of Singapore and Rotterdam are large transshipment ports; the Port of Immingham, Port of Liverpool, Port of Southampton, and Port Los Angeles all handle a diversity of cargos. These case studies shed light on how the seaports are taking steps towards net zero. A few points can be drawn from these case studies:* Most case ports have explicitly stated their aims to reach **net zero emissions** from their own operations (scope 1 and scope 2 sources) by 2040. This is more ambitious than IMO's target for net zero by 2050. * Most case ports have been pursuing **operational measures** to improve efficiency and reduce fuel consumption. * All case ports are implementing time-phased **technical measures** of equipment/vehicle replacement, e.g., replacing diesel with low-carbon fuels or electricity or hydrogen; the implementation process is carried out phase by phase considering the availability of fuel/energy supply, the supporting infrastructure, and the cost-benefit ratio. * All case ports are committing to time-phased **infrastructural measures**, e.g., installing electric charging stations, increasing electricity supply capacity, installing energy-saving devices, expanding rail service capacity for modal shift, and building alternative fuel facilities. * All case ports are pursuing time-phased **fuel and energy measures**, especially vehicle electrification and the exploration of the usage and production of low-carbon fuels such as hydrogen. * Some case ports have tried **digitalisation measures** to improve operations and reduce emissions; however, it appears that the applications of digital technologies and artificial intelligence (AI) are still in the early stage, especially in the UK ports. * Some case ports have initiated **policy and collaboration measures** to facilitate emission reduction; however, the scope and scale are still limited. Based on the above case studies, the literature review, and our domain knowledge, we propose a generic roadmap for seaports to achieve net zero in Figure 2, in which important solution measures within each category are divided into three phases: 2025, 2030, and 2040. The timeline of the roadmap is divided into three phases. In the first phase up to 2025, operational measures mainly focus on equipment and resource and subsystem optimisation; stakeholders are largely working in silos due to the lack of data visibility and the challenge of interoperability. This is especially true in the maritime sector because of the rather conservative and risk-averse nature of the shipping industry [66]. Technical  
Figure 2: A roadmap of seaport decarbonisation to net zero with time-phased solution measures. measures focus on upgrading or retrofitting the existing equipment to be more energy-efficient, and phasing in less energy-intensive electric equipment and HVO-powered equipment. From the fuel and energy perspective, electrification and low-carbon fuel are mainly applied to light-duty vehicles and equipment at this phase. The difficulty in electrifying energy-intensive equipment is due to the unavailability of electrical power supply and infrastructure. At this phase, ports have started the use of energy generated from solar panels and wind. Infrastructurally, energy-saving devices and measures have been deployed, such as LED lighting; electric charging stations are installed to support the equipment electrification. In addition, rail service capacity expansion has been carried out to facilitate the modal shift, for both logistics efficiency and emission reduction.