Last reviewed 2 May 2023

The Government has set its sights on decarbonising the entire transport system by 2050, in line with legally binding net zero emissions targets. In this article, John Barwise reviews the plans for each transport mode and the direction of travel for UK businesses.

Transport is fundamental to the movement of people and goods around the UK, and it is worth over £100 billion a year to the economy through both transportation and transport manufacturing.

However, transport is also the largest contributor to UK domestic greenhouse gas (GHG) emissions. Without a fundamental reduction in transport emissions, the UK will fail to meet its net zero commitments.

The Department for Transport’s (DfT) Decarbonising Transport: A Better, Greener Britain publication sets out the Government’s plans to reduce emissions across all modes of transport and the vital role that innovation, infrastructure and modal shifts will play in achieving net zero by 2050.

Zero-emission vehicles (ZEVs)

In 2022, transport accounted for 34% of all territorial carbon dioxide (CO2) emissions, compared to around 31% in 2020. According to UK domestic transport figures for 2020, transport was responsible for 24% of the UK’s total GHG emissions, with cars and taxis accounting for 52% — the highest emissions across all transport sectors.

In 2021, over 18% of new cars sold in the UK were electric or plug-in hybrid vehicles (PHEVs). In 2022, the proportion of new plug-in vehicles sold rose to over 22% and is expected to rise again this year. The sale of electric vans is also rising, with forecasters revealing over 30% increase in battery electric van deliveries last month, compared to the same period last year. Electric vehicle (EV) sales outstripped diesel sales last year.

The rise in EV and hybrid vehicles is due to several factors, including much lower running costs, the phasing out of petrol and diesel cars and the introduction of clean air zones (CAZs) that imposes charges on the worst polluting vehicles in major cities. The Government has set a target of 100% of its own car and van fleet being zero emission by 2027 — 25% of its vehicles are already ultra-low emissions.

More recently, the Government has announced a new mandate requiring manufacturers to progressively increase their percentage of new zero-emission vehicle (ZEV) sales in the UK, with a target of 100% by 2035. The ZEV mandate represents a fundamental shift in how the UK regulates CO2 emissions from new cars and vans, and it creates opportunities for new jobs and investment.

To accelerate the drive to ZEVs, the Government has also introduced a revised Electric Vehicle Infrastructure Strategy action plan for the rollout of electric charging infrastructure. This move is in response to concerns that there are not enough chargepoints and these are unfairly distributed, with a higher concentration in London compared to other cities and regions.

In June 2022, the UK had over 31,000 public chargepoints, of which nearly 6000 were rapid chargers and most of these are in London. Analysis from the County Councils Network (CCN) shows there is one charger available for every mile on average in the capital compared to just one every 16 miles in English counties. The current plan is for around 300,000 public chargers by 2030, supported by an additional £56 million of support to continue the expansion of EV charging across the country.

Heavy goods vehicles (HGVs)

The freight industry is one of the more challenging aspects of decarbonising the transport system.

An estimated 1.6 billion tonnes worth of goods are transported in and around Britain each year and most of the freight is moved by road.

Freight contributes £127 billion to the economy each year and supports £400 billion in manufacturing sales. Yet road freight is also responsible for over 20% of our domestic transport carbon emissions when combined with domestic shipping freight.

Under current proposals, the sale of new, non-zero-emission HGVs that are 26 tonnes or less will end in 2035. The sale of other new non-zero-emission HGVs will end by 2040.

Most HGVs are well over 3.5 tonnes and carry heavy loads over long distances, requiring large batteries and suitable charging infrastructure which, combined with the logistics of moving freight around the UK, makes the transitioning to zero carbon even more challenging.

The DfT recently completed a Zero Emission Road Freight Trial programme, which included six feasibility studies and the deployment of 20 battery electric rigid trucks into NHS and local authority fleets. A further £200m demonstration fund has also been approved to create an evidence base to determine which technology mix is best suited to decarbonise the heaviest road freight vehicles (40–44t trucks) and address barriers to infrastructure rollout.

Funding to support the transition to electric vans and trucks includes a discount of £16,000 for some small trucks between 4250kg and 12,000kg gross weight. Larger trucks over 12,000kg are eligible for a discount of up to £25,000, with conditions attached. Further details are available at GOV.UK.

The DfT has also set up a new industry-led forum to help the freight sector decarbonise and ensure its long-term sustainability. The Freight Energy Forum is a partnership between industry and the Government to help the freight sector achieve net zero by 2050 across all modes — including rail, road, air, maritime and warehousing.

The forum will also contribute to the Government’s Future of Freight Plan which sets out how the UK can deliver a cost-efficient and sustainable freight sector for the long term.

Buses and coaches

Buses are one of the least carbon-intensive forms of road vehicle transport per passenger per mile in the UK and remain the most popular form of public transport, accounting for around 50% of all journeys on public transport. Combined with coaches, they represented only 3% of UK transport emissions.

The Government wants to accelerate a modal shift and make public transport, cycling and walking the natural first choice for journeys. So far, the Government has funded around 2000 new zero-emission buses (ZEBs) through its Zero Emission Bus Regional Areas (ZEBRA) Scheme.

A zero-emission bus reduces carbon emissions by about 70% (46 tonnes) annually compared to a diesel bus and also avoids the 23kg of nitrogen oxides (NOx) emitted each year by a diesel bus. The Government defines zero-emission buses as those with zero emission at the tailpipe and have a zero-emission bus certificate.

Over £320 million in funding has been allocated to the introduction of ZEBs and supporting infrastructure and is planning to reform the Bus Service Operator Grant to accelerate the take-up of zero-emission buses. The Government has also promised a further £200 million in funding for zero-emission buses over the Spending Review period.

Decarbonising railways

The rail network will play a vital role in decarbonising the transport system. Rail is a safe and low-carbon way of moving people and goods over long distances, making up just 1.4% of the UK's domestic transport emissions in 2019. On average, rail freight trains emit around a quarter of the CO2 equivalent (CO2e) emissions of HGVs per tonne mile travelled.

The UK rail track network is 38% electrified already, and further expansion is seen as the optimal way of decarbonising most of the remaining network. Other options being considered include battery-powered trains and new technologies such as hydrogen.

A key proposal includes consolidating responsibility for the whole rail system into one organisation, Great British Railways (GBR), which the Government argues will integrate and simplify rail travel while potentially saving taxpayers around £1.5 billion a year.

Passenger trains produce a third of the emissions of the average petrol car for every passenger mile travelled. Studies by GBR’s Transition Team estimate that rail freight trains generate about 76% fewer carbon emissions compared to HGVs per tonne of goods transported.

The GBR Transition Team plans to develop a rail decarbonisation programme in preparation for GBR's formal establishment, considering ways to increase the amount of freight transported by rail, as part of the wider plan to decarbonise the UK’s logistics chain and reduce road freight.

Decarbonising shipping

Shipping is the way most goods are transported around the world, with over 90% of traded goods carried by sea. The shipping industry is also a major emitter of GHG with a global carbon footprint of around 3% — larger than some industrialised countries.

As a global trading nation, the maritime sector moves 95% of the UK’s trade in goods. As an industry, the UK maritime sector contributes nearly £40 billion to the economy and employs over 180,000 people.

UK domestic maritime vessels represent around 6% of the UK’s domestic transport GHG emissions, equivalent to over 5 million tonnes of CO2e — more than domestic rail and bus emissions combined.

Maritime has traditionally been described as a “hard to abate sector”, but multiple energy options are emerging that can deliver zero or low-emission shipping, including solar power, efficient batteries, liquified gas, hydrogen, ammonia and methanol, as well as integrating ports into decarbonised energy networks.

Other initiatives, such as the Clydebank Declaration established at COP26, aim to establish “green shipping corridors”, which involve specific shipping routes between two ports with zero emissions. The initial aim is to decarbonise a minimum of six shipping routes by 2025.

The Government has set out a Clean Maritime Plan with commitments to achieve net zero for the UK domestic maritime sector, including indicative targets from 2030 and net zero as early as feasible. Various structures such as the Maritime Research and Innovation UK (MarRI-UK) and a new UK Shipping Office for Reducing Emissions (UK SHORE) have been put in place, combined with several funding streams to support these ambitions.

There are issues relating to best technologies and multinational collaborations that still need to be resolved to realise the Government’s net zero ambitions in the long term, but the Clean Maritime Plan sets the framework and the timetable for this to happen.

Zero-emission aviation

Aviation represents around 8% of UK GHG emissions, of which less than 2% comes from domestic flights. The plan is to significantly reduce emissions in line with 2050 targets through a combination of new aerospace technology such as electric and hydrogen aircraft, sustainable aviation fuels, operational efficiencies and market-based measures.

Former Transport Secretary Grant Shapps announced the creation of a new Jet Zero Council in 2020 to help deliver new technologies and innovative ways to cut aviation emissions. The council will focus on developing capabilities to deliver both net zero and zero-emission technologies and is supported by delivery groups focused on sustainable aviation fuels (SAF) and zero-emission flight (ZEF).

As part of the plan, the Government is also considering ways of aligning the UK Emissions Trading Scheme (ETS) with net zero and phasing out fee allowances for aviation. A £3 million of funding has been allocated for research and development into ZEF infrastructure, with a further £15 million towards advancing SAFs.

A short-term target is to facilitate a “world first” 100% SAF transatlantic flight later this year, fuelled by SAF produced by UK-based engineering group Velocys. The Government will also launch an additional £165 million SAF industry competition over the next three years to support further SAF development.

The Zero Emission Flight Delivery Group will focus on zero-emission aircraft and the ground infrastructure needed to support zero-emission flight, including a regulatory framework. Key findings so far include the need for new standards for fuel storage, such as hydrogen and electricity charging infrastructures to support zero-emissions flights. 

A parallel programme FlyZero, run by the Aerospace Technology Institute with funding from BEIS, focuses on research into zero carbon emission commercial flights. The project is exploring key technologies to unlock liquid hydrogen flight and the infrastructure needed to support it.

The Government’s Jet Zero Strategy, published last year, includes a commitment to having at least five commercial-scale UK SAF plants under construction by 2025 and to continue supporting the aviation industry in developing the ground infrastructure necessary to fuel and handle zero-emission aircraft.


The long-term ambition is to drive down GHG emissions from all modes of transport and progress so far indicates that we are already changing the way we travel and how we get there.

The UK's sixth Carbon Budget will, for the first time, incorporate international aviation and shipping emissions, which the Government says will bring the UK more than three-quarters of the way to net zero by 2050.

A clear benefit from having a net zero transport strategy is the opportunities it offers for developing innovative ways to reduce GHG emissions and improve efficiencies across all modes of transport — innovations and technologies that will likely spill over into other manufacturing sectors, encouraging more investment in the “green revolution” and the jobs this will create in the long term.

The scale of ambition needed to achieve net zero across the whole transport sector will be challenging and may not be realised across all modes of transport by 2050. Nonetheless, the direction of travel is clear.