How the UK tackles its transport emissions is critical to its ability to show leadership when co-hosting November’s COP26 climate conference. Domestically, surface transport now emits more than any other sector while the UK’s aviation industry has the third highest emissions of any country in the world. With our submission to the Committee on Climate Change’s (CCC) call for evidence for the Sixth Carbon Budget, covering 2033-37, HSRG makes the case for the green potential of High Speed 2 to be maximised by delivering it quickly and integrated in an ambitious wider strategy.

The Paris Agreement requires each country to set out measures to deliver a net zero compliant trajectory in a strategy known as a Nationally-Determined Contribution (NDC) focusing on 2030. For the first round of NDCs, European Union states submitted a combined NDC. Brexit now provides the opportunity for the UK in its first ever NDC to set out a higher level of ambition.

Transport has more than its fair share of breakthrough technologies promising solutions. These are however unlikely to be scalable for 2050, let alone 2030, and many have hidden carbon, energy and other resource constraints. Behaviour change is therefore crucial to prevent a climate emergency. The challenge is the UK has the fastest growing rail network in Europe but between some of our biggest cities it is also the oldest. We are running out of space on the routes where capacity is needed the most to provide alternatives for journeys that are hardest to decarbonise.

Harnessing the potential of HS2 to become the net zero spine of our transport network is key to addressing this. So too is its ability, as Europe’s biggest construction project, to catalyse net zero transformation more broadly across the economy.

The recent Oakervee Review recommended making HS2 part of an integrated wider government strategy to “achieve significant modal shift from both road and air to rail”. Freight is often forgotten but should be included too. Dissuading use of higher carbon travel, as both Oakervee and the CCC recommend, will increase the rate of growth on the rail network further.

We therefore need to open the first section of HS2 to Crewe by 2030 or as soon after as possible and then the remaining sections. Even this first section will deliver transformative reductions in journey time, for instance saving over half an hour to Scotland, increasing demand and with it pressure on crowded railways. Work on further rail enhancements to Scotland, Wales and the South West needs to start soon. Regional ambitions such as those of Midlands Connect to create new local and regional services on existing railways freed up by HS2 should be progressed quickly. By leveraging the potential of HS2, we can help design out domestic mainland flights and a decisive shift towards public transport.

The scale and pace of transition that net zero requires means we cannot simply look at each sector of the economy in a silo, however. Wider interactions have to be considered, such as the construction and maintenance requirements of transport networks and the vehicles that use them. In the construction sector, the scale and ambition of HS2 is catalysing new techniques such as offsite construction, hybrid diggers and Building Infrastructure Modelling to reduce resource requirements. These alone could reduce its forecast carbon footprint by 20-30%. Rail oriented development encourages compact housing, which can require as little as a quarter the energy to construct and heat as sprawling detached homes and even less land. With demand for new housing high, it is important to unlock more sustainable forms of development and a project the size of HS2 can bring different levels of government and developers together more than smaller individual ones.

As the first major economy to adopt climate change legislation then a net zero target, the UK has a head start. It is important that successes and learnings – from industry as well as government – are shared globally to inspire and help other countries to decarbonise faster. With the main construction work for HS2 due to start this spring, HSRG will be sharing more inspiring case studies and statistics from the project in the run up to the COP26 conference.