A report has been published looking at the environmental impact of HS2, and with some caveats, is largely positive about how HS2 will improve the environment.

Commissioned by the High-Speed Rail Group, it doesn’t look at CO2, but at biodiversity in nature along the railway, before and after it’s built and what impacts the railway will have.

Let’s get the elephant out of the room, a report by an organisation called High-Speed Rail Group is never going to put out a report critical of high-speed rail, just as a group called, for example, StopHS2 is unlikely to ever put out a report that’s positive about HS2.

The facts sit somewhere between the two, and reports by both sides of the debate should be read to get a balanced approach to the debate.

While the detractors say that HS2 has a damaging effect on wildlife, the report suggests that once construction works are over, the benefits of the “green corridor” being built around HS2 turns the project in effect, into an environmental positive.

That’s just in terms of plant and wildlife alone.

The benefits from shifting road and air traffic to rail, and boosting commuter rail is a substantial CO2 and environmental benefit of its own.

One of the bigger benefits of a long railway is that it’s able to create links between pockets of wildlife otherwise isolated in bubbles of modern farmland. The ribbon of nature running alongside existing railways is one of the lesser appreciated aspects of the UK’s railway infrastructure.

It does, however, fit in with modern thinking about how to support biodiversity in the countryside, rather than trying to protect the bubbles as isolated entities, to join them up into larger bubbles, using the railway as the linking joints.

The report notes that Phase 1 of the HS2 project creates more of these green bridges than currently exist in the UK.

One of the reasons why HS2 can be better at creating these wildlife corridors is because of the thing that often makes anti-railway campaigners hate the railway — it’s wider than a normal railway.

Although the trackbed is only about a metre wider than a slower railway, because it needs to be straighter, that often involves more embankments and cuttings than a slower railway would need — and those wider slopes needed by HS2 aren’t used for farming, and so make for much wider nature corridors between isolated pockets of woodland.

It’s seemingly a paradox that high-speed rail can do more to improve biodiversity than a slower railway could achieve.

However, one of the controversial aspects of HS2 is ancient woodland. As has been previously shown, the practical impact is — to use a loaded term — negligible as a percentage of the total remaining. And as so much more woodland is being planted than destroyed, the long term effect is a net gain in woodland — some of which will, in turn, go on to become ancient itself over time.

HS2 could have reduced the ancient woodland impact further by being more curvey in design — that is fewer straight lines cutting into small woods scattered along the route — but curvey railways tend to be slower railways, and a slow railway cannot be upgraded later to a fast one, whereas woodland regrows.

Responding to the seemingly inevitable rise in temperatures, about a third of the newly planted trees are species that thrive in slightly warmer climates. A sensible mitigation to climate change, if a regrettable necessity.

The impact of climate change is also a reminder that railways are a far less damaging way of travel than cars and planes, and railways being fast is likely to be a key selling point for long-distance travel.

As the report notes, the UK is unlikely now to ever be a biodiversity hotspot, too much damage has been done in the past, but the opportunity caused by the construction of HS2 should be a trigger to improve wildlife along the route and help join up those isolated wildlife bubbles severed by the rise of modern life.

It does, however, highlight a disappointing situation, in that the anti-railway lobby is now so angry that environmental mitigations are being hidden from view or otherwise delayed to avoid too much local publicity. This causes a feedback loop of only the bad news being reported, so HS2 looks worse than it is, leading to more angry voices joining the protests.

Landowners and engineers are deferring environmental improvements to avoid becoming targets for the activists.

Regardless of your views about something, people living in fear is not a solution to anything.

That sort of thing has to stop.

The railway is being built – let’s work to maximise the environmental benefits that come from it.

The report is here.


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  1. Alex McKenna says:

    If HS2 helps to reduce the burning of fossil fuels, then let’s have it working as soon as possible.

    • My calculations show that you could make 30 trips from London to Birmingham by car for the CO2 output of a single journey on HS2 using current electricity CO2 levels.

      Of course by the time it starts, the power for HS2 could be zero carbon.

      HS1 has already done this.

      And not by “planting trees to compensate” by removing carbon emissions from the electricity production.

      It does my head in the XR go after this service and the DLR, both systems that are very low carbon by design.

    • ianvisits says:

      Your calculations are the only ones I have heard of where it’s possible to make one conventional car journey emitting less CO2 than an electric train, let along make 30 of them.


    • John Green says:

      The best independent estimates are that even if HS2 delivers on its promise of getting freight off the roads and onto the rails, it will take around 50 years to pay back the emissions generated in its construction. And these woodlands will *not* fully regenerate in fifty years. Some trees may grow, but the fauna and fungi will be lost forever. “New” woodlands are not as bio-diverse as ancient woodlands and as the article itself says, different species will be planted (assuming the promises are kept).

    • ianvisits says:

      When dealing with climate change, long term thinking is something to be applauded, so that people are willing to put in the effort today that they personally will never see any benefit from – which is why I find it peculiar that one of the anti-HS2 arguments put forward is that they want short term patches, rather than long term gains which will be reducing CO2 emissions for centuries to come.

      Very odd indeed.

    • Ian says:


      “When dealing with climate change, long term thinking is something to be applauded (snip)… Very odd indeed (to favour short-term solutions).”

      Long term solutions are worse than useless!

      If atmospheric CO2 concentrations are important, it is essential to reduce them immediately, if not yesterday.

      HS2 has the effect of increasing CO2 emissions in the medium-long term and then slowly reducing them over a very long timescale (100+ years). From a climate change perspective, this is worse than doing nothing at all. To ensure the least damaging (though still hardly great) still possible scenario emissions have to be lower *this year* not in 2120.

      By 2120 there is a fair chance of a sea level rise of 0.5-1m or a global temperature rise of 1.5-2C… just as ‘the environmental benefits of HS2 might start to kick in’.

      Too little, far too late (and all at a massive immediate economic environmental cost)

    • ianvisits says:

      Assuming that people will still travel – then it’s important to develop the least damaging travel possible. HS2 is so much better than cars, but people object to building a railway. Odd.

      It’s interesting that the people complaining about a railway which will eventually do a lot to reduce CO2 emissions, but there’s total silence when it comes to all other forms of construction which will never break even in terms of CO2 emissions. The day the activists turn up at a housing estate to stop new houses being built, to stop new hospitals being built, to stop new schools being built — is the day I will cede that they might have a point.

      Odd though, it’s only an environmentally friendly railway that will reduce car, lorry and plane use that gets the protests.

      Clearly, it’s not CO2, but something else that people object to.

    • Anonymous says:

      Uselessly slow to get this built, by the time it’s built we’ll be flying in electric planes everywhere anyways.

    • Ian says:


      “Odd though, it’s only an environmentally friendly railway that will reduce car, lorry and plane use that gets the protests…”

      HS2 is not ‘an environmentally friendly railway’ – it, according to its own figures, will possibly be carbon neutral (i.e. just start to be better than not building it in the first place) in about 100 years… a little over 100 years too late to make any significant difference (and actually makes things worse in every one of the preceding 99 years).

      *A different* new railway could indeed be environmentally friendly. But it is simply irrational to think a ‘high speed point to point passenger service’ is the obvious and best solution to moving freight of roads. It is also hardly an ideal solution to reducing CO2 from passenger journeys… simply reducing the number of passenger journeys by facilitating tele-conferencing would be a far cheaper way to go.

      What HS2 is and always has been since it was imagined by Peter Mandelson et al. was ‘an economic stimulus project’. Its function was secondary to the amount of money spent. HS2 is a solution in search of a problem as evidenced by the rationalisations used to justify the price tag: “it’s all about speed” “its all about capacity” “its all about freight” “its all about levelling up the North” “its all about being environmentally friendly”

      Clearly these rationalisations are just garbage, a solution *designed* to address any of these problems would not look like the solution to any of the others (or if you wish, there is no single solution that can adequately address all of these issues… even if it costs more than 5% of annual GDP)

      As for your other point, I *do* oppose all building projects, at least those that happen on greenfield sites before former industrial sites are used. But even if I did not, the examples that you suggest (hospitals, houses, schools, etc) do differ from HS2 in one, dare I say significant, way… they provide clear well-defined benefit to people.

    • Sean says:

      My understanding is that the main CO2 emissions argument against HS2 is that it will likely increase the amount of air travel by increasing the capacity and reducing time to access the regional airports from London. The extra runway at Heathrow seems unlikely to ever be built so HS2 is a useful work around to free up some capacity.

      It’s impossible to have certainty either way on the environmental impact of long term infrastructure. Hydrogen powered planes, autonomous electric vehicles and remote meetings(!) could all be a game changer when it comes to transport.

      I come down on the side of building it and agree with @Ianvisits that we should now attempt to maximise the environmental benefits. Some protest ‘noise’ is inevitable and should be listened too but hopefully the decision makers will follow a balanced, evidence based argument.

    • Dave says:

      @Brian Butterworth

      I am not sure how you arrive at your conclusion.

      Energy use for a high speed train travelling at 320 km/h averages 30 Wh/seat-km (“L’AGV,au service de l’écologie”, Alstom, SIFER conference, May 2009). Siemens is claiming the Velaro Novo will be even lower than this.

      Grid CO2 emissions for the UK in 2019-20 averaged 198 g/kWh with transmission loses of 12% (BEIS, Fuel mix disclosure table).

      Put that together and emissions per pax could be <7g/kWh *now*.

      30 * 0.198 * 1.12 = 6.65g

      There is no car anywhere near this – even the best electric cars would use 5 times as much at motorway speed.

      Emissions from the track construction also have to be considered. Emissions from HS2 Phase 1 are ~6 Mt and from Phase 2a ~1.5 Mt. Of course how much of that should be attributed to each passenger depends on the number of passengers switched from other more polluting modes.

      There is an oft-quoted number that is loved by HS2-antis of "carbon neutral in 120 years", based on information published by HS2 Ltd themselves. Dig into this and you find it is totally false for a couple of reasons:

      1) DfT rules on modelling include a cut-off in passenger growth after 17 years. In HS2's case, that is only a couple of years after Phase 2a is planned to be in use and hamstrings the effects of passenger growth from the mid-2030s onwards.
      2) Some bizarre assumptions on modal switch are assumed, for example trips on weekends didn't count, return trips starting on a Friday and returning on a weekend counted for half (thus downgrading many leisure trips), aviation growth was assumed to grow unfettered rather than runway availability making it more favourable to switch domestic passengers to the train, business passengers would take cars/taxis to the airport but not Euston, and it appears that Edinburgh airport was not modelled but Cardiff was…

      The bottom line is I really urge people to download all the consultants' documents that fed into the modelling and the references they cite, such as reports from the CAA. It looks like some bonkers assumptions were made in the run up to the original 2013 bill documentation that detract from the overall business and emissions case for the line (the same issues also detract from the HS1-HS2 link case, but that is for another day). There was a huge drop in the rail market share between the 2011 and 2013 analyses, after the change of these DfT rules.

      On the other hand, if you take the well known S curve that plots rail market share against journey time, we could expect a swing to HS2 from the air market destinations it will serve that actually cancels its carbon debt in 25 years. To be clear, that is 25 years from air alone, not including swing from road or the improvements from increased rail freight capacity.

      Taking the impact of the WCML upgrade in the mid-00s on London-Glasgow journey times, the rail/air market share swung exactly in line with this S curve, so there is no reason to suggest the impact on the UK market will be any different.

      Indeed if you look at the impact Eurostar had on the London-Paris market, the CO2 savings from reductions in flights cancelled the emissions from the construction of HS1, Channel Tunnel and LGV Nord in 13 years. In other words, with the last part – HS1 phase 2 – opening in 2007, that route is already carbon neutral.

      London – Edinburgh/Glasgow is now Europe's busiest air market and to think that shaving an hour off the rail journey time will not make an impact is just wrong. If anything, there is a case for an HS2 phase 3 to bring the journey time down by a further hour to all but eliminate the air market.

      Having said all that, I never see anyone take motorway construction emissions into account when doing this comparison. If the entirety of a 2 track railway can product emissions of millions of tonnes, then surely an 8 lane motorway is worse?

  2. Lionel Ward says:

    Great coverage of an important and underreported subject

  3. Mark Harrington says:

    Waste of money and an environmental disaster – stopHS2

    • ianvisits says:

      Nice, if rather an unilluminating soundbite – any chance of illuminating us as to which parts of the article you disagreed with?

  4. Lisa Maughan says:

    You cannot obliterate ancient woodlands and make up for it by planting new trees it takes centuries to build up the biodiversity and symbiotic relationships found in these kinds of woodlands. This article is ridiculous!

    • ianvisits says:

      What’s rediculous is responding to a report which goes into a lot of detail about how soil transplantation works, without explaining why you disagree with the studies into the impact of doing that for HS1 etc.

      Fewer soundbites and more reasoned responses please.

  5. Adam says:

    While I have a few reservations about how much money is being spent on HS2, I appreciate how you lay out the facts like this. This article also seems more balanced than some of your previous on this topic 🙂

  6. Rosemary Robinson says:

    Why not just create a wide wildlife corridor and forget about HS2?

    • ianvisits says:

      Why not do both – all the benefit of the wildlife corridor and all the benefit of additional rail capacity so that there will be fewer cars and lorries on the roads.

  7. Steven Whatcroft says:

    The carbon emissions from building HS2 (over 20 years) are less than one months emissions from UK road traffic. The reductions in road usage that happened for COVID has more than “paid” the HS2 CO2 budget.

    The “but trees, but carbon” arguments are being tirelessly recycled by the anti-HS2 lobby because they have nothing better and often it’s just a disguise for NIMBY’ism. One only need to look at the inconsistency and often contradictory nature of their arguments.

    Another commentor mentioned XR – they are not and environmental group. There’s a intelligence report on XR which describes that the are a group of leftist anarchists who’s objective it to bring down democracy and free markets and impose their own communist dictatorship. “Environmentalism” is a fig leaf to disguise their true intent and suck in a few gullible, if well meaning. eco-teenies.

    • Jma says:

      On the topic of HS2, although I do think the damage to ancient woodland in some places is unacceptable, on balance it is still a positive project and environmental groups should focus their attentions elsewhere, in my view. I do understand why groups like the Woodland Trust, however, will be heavily involved given this is one of the few projects in the country allowed to demolish ancient woodlands and quite a few at that. Simply relocating or carbon offsetting these isn’t enough.

      On your final paragraph on XR, I think anyone who believes that Climate Change is a real problem requiring significant changes to the way we live (in the west) needs to recognise that only a radical overhaul of our economic and political system will achieve that. Capitalism and consumerism will never deliver the changes needed because it just isn’t in the interests of the ultra-rich to change the system. Naomi Klein’s “On Fire” is an amazing book on this topic which I thoroughly recommend you read.

  8. MilesT says:

    Does the report say anything about how wildlife crosses the railway line in a way that limits amount that is killed and protects the safety of trains?

    I’m thinking of some of the measures put into place for major road schemes to provide access across the road through the placement of modest size culvert piping to allow linking of habitats either side for smaller animals. But not sure what would happen with free ranging deer.

    (After hitting a deer once, I put “deer whistles” on all my cars in the hope to prevent a recurrence–they may not work in practice, but not expensive so why not)

    • ianvisits says:

      There’s a link to the full report at the bottom of the article.

    • MilesT says:

      OK, so I have now read the report to try and answer my own question, and am replying for the benefit of others.

      And, the answer is…unclear.

      Some mention is made of habitat “severance”, culverts (and the limitations of previous culverting use on similar projects), design of overpasses to support some movements, lengthening of viaducts to mitigate severance, minimal animal mortality due to passing trains.

      And one “green skew bridge” in one location (without really explaining what one is or where it will be)

      Much is made of the needs of bats, some of butterflies, rather less for other fauna (deer, fox, badger, hedgehog, newt)

      The approach seems to be “we will have flexibility in the detailed design at a later stage and we promise to use that”

      On this general question, I rate the report a C (mainly on their descriptions of woodlands, bats and green corridors).

      I’m no expert, though, and I am sure an expert would find a lot of holes, and much room for practical, reasonable improvement with engagement rather than outright condemnation. I hope a suitable expert can review this and call HS2 to account.

  9. Andrew Pickering says:

    The High Speed Rail Group behind this ‘report’ are vested interests…. Bombardier..Hitachi..Costain.. Siemens..Jacobs etc etc, all the companies with their snouts in the trough.
    As Malcolm Tucker says…you only need to ask the ‘right’ experts.
    Shameful stuff.

    • ianvisits says:

      I addressed that aspect in the article.

    • John Watkins says:

      If reports say that HS2 should be be cancelled and the government does cancel, won’t the construction companies will still get their money (or at least large cancellation fees)?

    • JohnC says:

      Why should the construction companies not get paid for costs incurred if they enter in good faith into construction contracts which are subsequently cancelled?

  10. John Hall says:

    Given there’s about 30 native British trees, what are the 10 species being planted?

  11. John Hall says:

    The release of CO2 (given its residence time) from the laying of the concrete bed and all other construction, what is being done to mitigate that now, not over the long term when it’s too late?

  12. Kevan Hubbard says:

    Where were the protesters when the M40 was forced through the Chiltern Hills?HS2 is nowhere as near as wide as a motorway plus dosn’t have unsightly side lines like services on it nor will it be lit with streetlights like the M40 is all the way from London to Stokenchurch despite the fact that cars and trucks have headlights on them for some reason.

  13. A B says:

    The assumption that this will all be built in accordance with the approved planning requirements is bold and utterly flawed. They are already making an absolute hash of it at the Birmingham hub. Trees which are required to be retained are not even fenced and consequently damaged by construction activity. The contractors absolutely do not give a monkey’s.

    In some cases important or irreplaceable habitats have been destroyed to make way for a temporary haul road or an attenuation pond. That this is the case is absolutely criminal and a staggering failure of the planning process.

    Translocating ancient woodland soil is like saying you’re still alive because we transplanted your organs into someone else. It’s not retained, it’s not improved, it’s lost and translocating soil is at best a token act which lets HS2 claim they’re doing something good.

    The report is extremely light on information about soil translocation, probably because it’s widely agreed to be a poor solution.

    The comparison to other countries’ rail network planning is laughable, particularly that of Germany which states it uses detailed ecological information to plan its transport network. This is definitely not happening in the UK!

    If this absurd vanity project is going to be built, which it seemingly is, it should be built well, not leaving a swathe of environmental destruction behind hastily papered over with new tree planting.

  14. John says:

    It would be useful if a parallel cycle path was built along the route.

    • Jim says:

      This was indeed proposed and a report identified it as the single most environmentally beneficial and cost-effective part of the entire project. Needless to say, it was thrown out by HS2 Ltd to save costs. How about a cycleway from London to Edinburgh with a green corridor around it for a fraction of the cost?

    • ianVisits says:

      How would a cycle lane between London to Edinburgh deliver the essential regional rail capacity for local commuters heading to work — which is what HS2 is all about doing?

  15. EBGB says:

    The ecological niches of ancient woodlands can’t just be replaced by replanting and waiting, unfortunately. There’s phenomenal symbioses between species which have evolved to live only with each other. Saying it’ll all be fine in 500 years is analogous to replacing St.Paul’s cathedral with a Norman Foster building because in 500 yrs the new one will be the same age. Age is not the point. The point is the diversity, which is always unique, and often the last refuge of very rare native species. I’m mostly in favour of HS2, but this should have been handled better.

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