A ‘greenprint’ for net zero in UK transport by 2050
Reported by Mala Virdee, PhD student, Department of Computer Science and Technology
In 2019, the UK government made a landmark, legally-binding commitment to achieve net zero greenhouse gas emissions by 2050. In 2020-21, the Department for Transport (DfT) set out its plans to deliver the rapid, transformative change required in the transport sector to meet this commitment in two reports: Transport Decarbonisation: Setting the Challenge (2020), and Transport Decarbonisation: A Better, Greener Britain (2021). These reports highlight aims to promote walking and cycling, decarbonise public transport, electrify road and rail travel, and accelerate maritime and aviation decarbonisation.
Harnessing academic expertise to achieve net zero
In June 2022, a cross-disciplinary group of academics met with Richard Bruce, DfT Director of Transport Decarbonisation, and Dr Bob Moran, DfT Deputy Director of Decarbonisation Strategy, for a Cambridge Zero Policy Forum discussion, bringing a broad range of academic expertise from across the University of Cambridge to bear on the challenges and opportunities raised by the DfT’s transport decarbonisation plans. Participants considered challenges including:
1. The UK is highly car-dependent: 91% of domestic transport emissions come from road travel, and whilst Electric Vehicle (EV) alternatives are gaining uptake, the vast majority of vehicles currently on the road are Internal Combustion Engine Vehicles (ICEVs) which will continue to be driven for a long time. A large-scale shift towards driving less is therefore critical if near-term carbon budgets are to be met, but will be challenging, given an entrenched societal dependence on car travel. Current analysis indicates that the increase in walking and cycle trips and the reduction of car trips seen early in the COVID-19 pandemic have not lasted, although the long term impact on travel patterns from the rise of remote working and new location decisions will take time to appear.
2. The EV transition requires infrastructure: It will be particularly important to ensure that a network of charging infrastructure is carefully planned to meet the needs of those making long journeys, and with consideration of inequity given that those without off-street parking may depend on costlier rapid public charging.
3. The EV supply chain will be strained by demand: Materials required for the production of EV batteries such as lithium and cobalt are in high demand across a variety of sectors, and this demand will increase as the automotive industry delivers on its pledges to transition towards EV manufacture. It is therefore likely that the supply chain for the manufacture of EV batteries and motors will be over-stretched and unpredictable at times, although there is no reason to think that this will persist for the long term.
4. Behavioural change can hinge on decisions made at the local level: Local authorities hold some key levers to help make bold and transformative decisions. These include, parking policies and provision of EV charging infrastructure, which could incentivise active travel, reduce car trips and increase EV uptake. However, local authorities are often hindered by funding constraints and limited capacity.
5. The technological pathways towards Heavy Goods Vehicle (HGV), maritime and aviation decarbonisation are currently unclear: Further research, development and trials are required to assess the feasibility of HGV decarbonisation targets. Whilst some battery and hydrogen solutions exist for small ships and planes, decarbonisation targets in these areas depend on ambitious future technological developments. Progress in the maritime sector is complicated by the need to deploy alternatives such as biofuels in step with an international network. Shorter term aviation targets depend strongly on Sustainable Aviation Fuel (SAF), the supply of which is currently highly constrained.
6. Political consensus on the net zero agenda is not guaranteed: Although there has been broad cross-party agreement on the importance of ambitious decarbonisation targets, political will can change rapidly. Long-term planning and investment is therefore subject to risk.
7. Losing public support would risk setting back the net zero agenda catastrophically: Some solutions which may seem straightforward economically - for instance, increasing fuel duty, or introducing road pricing systems - are highly unpopular. The complex and diverse needs and concerns of people affected must remain central whilst implementing ambitious policies and moving as rapidly as possible towards net zero targets.
Participants discussed lessons that can be learned from cities that have succeeded in making cycling the most popular mode of transport - for instance, in Copenhagen, 60% of journeys are made by bicycle. Participants suggested this has been made possible by a well-coordinated, long-term cycling strategy over the past 20 years, with continuous review and investment - not by one-off pieces of legislation. The dividends paid by this approach are apparent in public surveys, where people indicate that they cycle because it is cheap and convenient to do so, rather than for environmental reasons.
There is a need to think beyond the needs of metropolitan centres - for instance, provision of low-carbon alternatives to long-distance car travel will be crucial. Coaches are currently under-utilised in the UK, and a modern, well-planned coach system could massively improve the efficiency of motorway travel and reduce the number of cars on the road.
The forum also discussed the scope for a more imaginative framing around reducing car travel. There could be a greater emphasis on generative possibilities rather than restrictions - fewer car trips would see the UK healthier, roads and city-centres less polluted, noisy and congested, and yield economic rewards. A city able to lead the way by demonstrating these effects could provide a powerful example for broader change.