High Speed 2 is being sold to the public as a crucial part of the UK’s low-carbon transport future. It has been promoted as a project that would provide a greener alternative to travellers by linking northern England with London, helping to reduce the UK’s emissions.

There is certainly a case for environmentally sustainable transportation. In 2018, transport was responsible for 33% of all carbon dioxide emissions in the UK. These are figures the UK government is keen to cut in order to meet its Paris Climate Agreement obligations and 2050 Net Zero pledge.

Will HS2 really help achieve the government’s environmental ambitions? In short, it is unlikely.

HS2 Ltd claims it could transport a person 500 miles on HS2 for the same amount of carbon it would take someone to travel 70 miles by car. However, even according its own forecasts, HS2 is likely to result in the emission of 1.49 million tonnes of carbon dioxide, due to the way in which it is constructed. Worse, the proposal to run trains at 360 km per hour will require 50% more energy than the existing Eurostar trains. Such specifications deliver insignificant economic benefits and also require carbon-intensive slab-tracks.

This does not even take into account the damage and disturbance HS2 will inflict on wildlife sites and woodlands. It is expected that 108 ancient woodlands will be negatively affected, as well as an additional 693 local wildlife sites.

Criticisms of HS2 have already been voiced strongly. The estimated cost of creating the network has already soared to £108 billion. There are fears that the (more difficult to quantify) environmental costs will also skyrocket.

Only recently HS2 Ltd admitted that in its 120-year lifespan, HS2 will probably never be carbon neutral. The environmental argument for the project is that it will transfer passengers from more carbon intensive modes of transport. Such presumptions are misguided. Indeed, electric vehicles – increasingly powered by low-carbon generation – are anticipated to dominate the motor industry by the time HS2 is completed, accounting for 60% of new vehicles by 2030.

The government’s own projections foresee a vast number of passengers transferring to HS2 from existing main lines, transportation which typically emits less carbon than high-speed trains. The Department of Transport has indicated that just 1% of HS2 passengers would be those who would have flown whilst 4% would have driven. The insignificant reduction in carbon from these modes of transport will be far outweighed by the environmental cost of HS2.

A recent report by Lord Berkeley suggests it is highly plausible that HS2 will not be carbon neutral during its lifespan. Moreover, the “parkway’’ stations HS2 plans to use will increase road traffic and congestion in the surrounding areas.

Of course, there are a number of ways that a high-speed line could be constructed in a more environmentally conscious way. Utilising existing rail infrastructure would reduce construction costs and limit the damage to local wildlife sites. Furthermore, reducing the maximum speed in certain areas would decrease carbon emissions, both during construction and from train journeys. However, this in itself is unlikely to be enough to cut emission levels to the point where HS2 is environmentally sustainable.

If the government truly wants to balance its infrastructure plans for the UK with its environmental aspirations, it should instead consider improving existing rail infrastructure and encouraging clean transport and energy innovation.

Smaller transport projects, such as increasing the efficiency and capacity of existing links, would present a feasible alternative to HS2. Crucially, such projects do not emit the vast quantities of carbon expected from building and operating HS2. Electrifying more railways (especially between northern cities) provides one environmentally conscious option.

Balancing environmental concerns and infrastructure demands is a precarious task. If the government seriously wishes to achieve both these ambitions, scrapping HS2 and examining alternatives is a strong way to start.