HS2 and the Environment

DateAug 19, 2016
AuthorEugenia Siccardi

In 2009 the UK Government proposed a Y-shaped rail line named High Speed 2 (HS2). HS2 is proposed to connect London to Manchester and Leeds, via Birmingham, the East Midlands, Sheffield and Crewe.

The project will be realised in 2 phases, the first includes the section from London to Birmingham, and the second phase will consist of two branches that will connect Birmingham with Manchester and Leeds 1.

High Speed Train

The works are likely to begin in 2017 and are projected to be completed by 2032. The HS2 railway line will provide ‘sufficient capacity to meet long term demand’ in terms of national transport1. Moreover, it will improve the connectivity and increase the quality and reliability of the network1.  When the railway is fully operative a decrease of car traffic is expected, along with a significant lessening of emissions 3.

The first phase of HS2 will span 230 kilometres (approximately 143 miles) at a maximum speed of 360km per hour (223 mph) (it will take 49 minutes from London Euston to Birmingham Curzon Street). It will create 14,600 temporary full time job roles during the construction phase, and an estimation of 30,000 permanent jobs related to the railway after its completion1,2. However, this project is already proving a more expensive venture than originally stated. According to the Institute of Economic Affairs it will cost approximately £80 billion to complete as opposed to the £43 billion declared by the Department of Transport in 20134.

There is a mixed reaction to the HS2 railway proposal and completion of the project is awaited with both enthusiasm and criticism. One public concern, among the others, is due to the potential impacts of such a project on the environment.

In accordance with the European legislation (85/337/EEC) on Environmental Impact Assessment process, the Government has been asked to produce an Environmental Statement (ES), completed by a group of independent environmental consultants on behalf of HS2 Ltd1,5.

Within the ES, the Government admits that the project, due to its nature and extension, will have a significant impact of the natural environment surrounding the works. However, it also proposed several measures of mitigation and compensation of the impacts in order to achieve ‘no net biodiversity loss’1,5.

What does it mean? On paper, although the project will run across two Sites of Special Scientific Interest (SSSI), 41 habitats of principal importance, 89 Local Wildlife Sites and 19 Ancient Woodlands5, ‘no net loss’ means that the adverse effects on sensitive sites will be mitigated or compensated to the point that the biodiversity loss at the end of the project1 won’t be assessed as ‘significant’.

Figure 2

Figure 1 – Mitigation Hierarchy - https://www.gov.uk/government/publications/hs2-phase-one-environmental-statement-non-technical-summary

The ES approach on the matter will follow the ‘mitigation hierarchy’ (shown in Fig. 2), and its sequential steps1,6. Therefore, the project has been designed in order to avoid significant impact on the local environment as much as possible through, for example, changes in alignment. The severity of unavoidable impacts will be reduced, abated or repaired, when applicable (e.g. noise barrier, tunnels…).

When permanent damage is impossible to avoid or mitigate, the impact will be calculated with a biodiversity metric offset calculation, and then compensated in order to achieve the ‘no net biodiversity loss’ through habitat recreation1,5.

Figure 3

Figure 2 – Tunnel portal (generic) in a rural location - https://www.gov.uk/government/publications/hs2-phase-one-environmental-statement-non-technical-summary

The biodiversity metric calculation is a rigorous and consistent tool, which has been developed by Natural England and Defra, and then nationally employed1,5,7. This system calculates the value in units of different habitats that need to be compensated7,8 (More information about this method is here, whereas an interesting read about the applicable ‘value’ of nature is here

Nevertheless, the ES has been subject to several criticisms regarding its approach and procedures.

For instance, a comment from The Environmental Bank on the ES underlines how the baseline data of the statement contains inaccuracies – for instance,  ponds close to Coneybury Wood, Middleton, where newts have been surveyed, was misinterpreted as woodland within the document)7.

Inaccuracy in the data could cause a mistaken evaluation of the habitat importance and consequently an underestimation of the damages, and then an inadequate compensation.

Furthermore, The Environmental Bank, as well as many local Wildlife Trusts affected by the HS2 project7,9,10, noted that the decision-making process adopted for the habitat compensation is not clear within the ES. This lack of clarity doesn’t allow the readers (stakeholders and private) to really understand the procedure and effectively quantify the net loss and the real compensation. As a result of this, it is not possible to verify if the project will effectively reach the ‘no net loss’ goal7,9.

Moreover, the offsetting calculation is not always applicable. There are natural environments such as Ancient Woodlands (AW) that are widely considered ‘irreplaceable’1,9,10. The reason for this is because their intrinsic value is due to their age, which is clearly not reproducible by any compensation1,7,9. However, the ES, even if recognising the impossibility to compensate such ecosystems, counted AWs within the offsetting calculation, therefore underestimating their value6,11.

When reading the ES, its non-technical summary and other informative documents available on the Internet, it is clear that the HS2 project is committed to following a sustainable approach and delivering a ‘no net biodiversity loss’. However, what is still missing is a clear baseline dataset and a solid and repeatable calculation able to strengthen the project. Furthermore, it has been argued that a flagship project such this one should point to a net gain of biodiversity rather than a ‘no net loss’7,9.


  1. London-West midlands Environmental Statement – Non-technical summary (On line – Nov/2013) https://www.gov.uk/government/publications/hs2-phase-one-environmental-statement-non-technical-summary
  2. HS2 to create jobs and boost skills as companies shortlisted for major engineering contracts (On line – 23/03/2016) - https://www.gov.uk/government/news/hs2-to-create-jobs-and-boost-skills-as-companies-shortlisted-for-major-engineering-contracts
  3.  Sustanable Statement (Appendix F – HS2 and Carbon) (On line – 10/2013) - https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/400836/hs2ml-carbon_assessment_and_narrative-_25thoct13_wed_tagged_version__-_updated_0.pdf
  4. Official figures underestimate the cost of HS2, Institute of Economic Affairs (On line – 30/09/2015) http://www.iea.org.uk/in-the-media/media-coverage/official-figures-underestimate-the-cost-of-hs2
  5. House of Commons, Environmental Audit Committee – HS2 and the Environment (On line – 02/04/2014) http://www.publications.parliament.uk/pa/cm201314/cmselect/cmenvaud/1076/1076.pdf
  6. The Biodiversity Consultancy – Mitigation Hierarchy (On line) http://www.thebiodiversityconsultancy.com/approaches/mitigation-hierarchy/
  7. Written evidence submitted by The Environment Bank (On line – 07/03/2014) - http://data.parliament.uk/writtenevidence/WrittenEvidence.svc/EvidenceHtml/7191
  8. The Environment Bank – The biodiversity metric – (On line – 2013) http://www.environmentbank.com/
  9. High Speed Two – Environmental Statement consultation, Response from the Berkshire, Buckinghamshire and Oxfordshire Wildlife Trust (On line – Feb/2014) - http://www.bbowt.org.uk/sites/default/files/files/BBOWT%20response%20to%20HS2%20Environmental%20Statement.pdf
  10. The Wildlife Trusts – High Speed 2, Impact of HS2 on the environment (On line) http://www.wildlifetrusts.org/hs2
  11. Woodland Trust – HS2 rail link – Our view (On line) http://www.woodlandtrust.org.uk/get-involved/campaign-with-us/our-campaigns/hs2-rail-link/our-views/