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Re: HS2

Posted: Mon Feb 08, 2021 1:54 pm
by plodder
Bird on a Fire wrote:
Sun Feb 07, 2021 6:57 pm
plodder wrote:
Sun Feb 07, 2021 4:38 pm
And here's a superb thread on carbon accounting for HS2: https://mobile.twitter.com/dpeilow/stat ... 8039778305
That is interesting. I had heard that the carbon accounting used pessimistic scenarios, but that does sound a bit absurd. Why hasn't adequate carbon modelling been done yet?

A huge part of the raison d'être for this scheme is decarbonisation, but nobody's bothered to demonstrate it numerically during the whole project lifetime? You've gotta admit that's a bit silly. At the very least they could have released a range of forecasts, like the IPCC do, rather than publishing a single definitely-unrealistic scenario and then having to say "ah but those numbers are actually definitely wrong and it'll be much better than that really".

I'd also like to see more joined-up policymaking around this. e.g., why not phase in a modal shift legislatively, by banning short-haul flights as different stages are opened up? (Obviously excluding stuff like air ambulances) Not a criticsm of HS2 specifically, but another area where the government could help to make the case with policies that complement each other.
My understanding is that they're following silly rules from Defra and my intuition is that it's been through several iterations. No criticism of the Green Party's piss poor approach, I notice.

Re: HS2

Posted: Mon Feb 08, 2021 1:59 pm
by plodder
Bird on a Fire wrote:
Sun Feb 07, 2021 6:46 pm
It would be more interesting to read arguments about why net biodiversity loss should be accepted by conservation NGOs, but nobody seems interested in engaging with the actual arguments sensible people are making. Much easier to pretend that critics think HS2 should be completely cancelled than address the more complex issues around connectivity and offsetting.
Well, the links I've posted go into quite a lot of detail about the enormous efforts that have gone into route planning to avoid habitat impacts, and I've not seen a single critic in the media, social media or on here engage in this at all. You seem to assume they've got a ruler out and drawn a straight line, and then put some wiggles in where there's a shopping centre or something. So, fill your boots. Find a better route.

Re: HS2

Posted: Mon Feb 08, 2021 2:33 pm
by Bird on a Fire
I'm not complaining about the route. I'm complaining about the compensation, which everyone from Natural England to the Wildlife Trusts agrees is inadequate.

People like the Green Party calling for the whole thing to be scrapped are going too far. The project is a useful one, but needs to minimise impacts on biodiversity in accordance with policy and conservation goals, and it's not currently doing that.

The message that most major conservation organisations are putting out is that HS2 should be done better. It's probably too late for Phase 1, but it would be good if the next phases take criticism on board and work with conservation experts to deliver something mutually acceptable, instead of trying to greenwash a damaging infrastructure project.

Re: HS2

Posted: Mon Feb 08, 2021 2:39 pm
by Bird on a Fire
El Pollo Diablo wrote:
Mon Feb 08, 2021 11:40 am
Bird on a Fire wrote:
Sun Feb 07, 2021 6:46 pm
So it's not clear who (if anyone) has said 108 ancient woodlands will be "destroyed" - but it doesn't seem to be any of the major NGOs. The thread is apparently arguing with a strawman.
It is certainly a claim being made by people out there - not least the group of protesters currently boldly preventing the extension of HS2 from Euston towards the River Thames. The Guardian has gleefully and repeatedly repeated it.
Fair enough - I have seen exaggerated claims from all sides. If people want to start twitter threads debunking those people I won't disagree, but putting words into other organisations' mouths in an effort to discredit them is dishonest.

In this day and age it's easy to find all sorts of people saying all sorts of things. I find it much more interesting to focus on official communications from important, accountable organisations than random protestors and (even worse) journalists and TV presenters. That's why I've stuck to reports from NGOs and government throughout the thread. There are plenty of well-informed reasonable nuanced criticisms to discuss, instead of smugly shooting small fish in a barrel.

Re: HS2

Posted: Mon Feb 08, 2021 2:45 pm
by Bird on a Fire
plodder wrote:
Mon Feb 08, 2021 1:59 pm
Bird on a Fire wrote:
Sun Feb 07, 2021 6:46 pm
It would be more interesting to read arguments about why net biodiversity loss should be accepted by conservation NGOs, but nobody seems interested in engaging with the actual arguments sensible people are making. Much easier to pretend that critics think HS2 should be completely cancelled than address the more complex issues around connectivity and offsetting.
Well, the links I've posted go into quite a lot of detail about the enormous efforts that have gone into route planning to avoid habitat impacts, and I've not seen a single critic in the media, social media or on here engage in this at all. You seem to assume they've got a ruler out and drawn a straight line, and then put some wiggles in where there's a shopping centre or something. So, fill your boots. Find a better route.
You're making the same mistake as the Green Party here. The choice isn't between current plans or no HS2. There's a third option, of HS2 with better biodiversity safeguards. if you want a detailed proposal, the Wildlife Trusts report I linked to on the first page is a good place to start.

Re: HS2

Posted: Mon Feb 08, 2021 2:57 pm
by plodder
The hierarchy for environmental stuff is to avoid impact where possible, then minimise impact and mitigate. If you're happy that HS2 is doing the latter then we're getting somewhere.

Please note the huge road building programme is not avoiding impact where possible. They're building loads of stupid new roads to fill up with traffic jams in order to free up habitat for new houses and shopping centres.

Re: HS2

Posted: Mon Feb 08, 2021 3:09 pm
by Bird on a Fire
I don't think I've ever said otherwise. Seriously, check the thread - you've been arguing against somebody's else's opinions this whole time.

As I understand it there are some sections of Phase 2 where people are calling for extra tunnelling to avoid habitat loss, but I do understand that there are all sorts of "train-physics" reasons why you can't just add extra bends. I wouldn't feel confident weighing in on the exact route without a lot of extra reading that I cba to do ;)

I do understand habitat creation and connectivity, which is why I've focussed purely on those aspects throughout the thread. HS2 is doing it very badly, creating a precedent that road- and house-builders will be able to rely on in court unless the legislation changes for the better (which it won't under the current government).

Re: HS2

Posted: Mon Feb 08, 2021 9:41 pm
by discovolante
Fishnut wrote:
Sun Feb 07, 2021 9:51 pm
jaap wrote:
Sun Feb 07, 2021 9:39 pm
Fishnut wrote:
Sun Feb 07, 2021 9:26 pm


Oh god no! Why???
99 Percent Invisible: For the love of peat
Thanks :) Downloading now
You will not be surprised to hear that Reforesting Scotland also has a lot of discussion about er, reforesting Scotland:
https://reforestingscotland.org/whats-new/ including the tensions between the various interests people have. Its relevance to someone who lives in the south of England might be limited but there are probably some general principles and themes that can be carried over to other environments. Probably.

Re: HS2

Posted: Mon Feb 08, 2021 10:04 pm
by Fishnut
discovolante wrote:
Mon Feb 08, 2021 9:41 pm
Fishnut wrote:
Sun Feb 07, 2021 9:51 pm
jaap wrote:
Sun Feb 07, 2021 9:39 pm


99 Percent Invisible: For the love of peat
Thanks :) Downloading now
You will not be surprised to hear that Reforesting Scotland also has a lot of discussion about er, reforesting Scotland:
https://reforestingscotland.org/whats-new/ including the tensions between the various interests people have. Its relevance to someone who lives in the south of England might be limited but there are probably some general principles and themes that can be carried over to other environments. Probably.
Oh, thanks!

Speaking from a position of "just enough knowledge to embarrass myself" the question seems to not be so much "do we restore an environment?" but "what do we restore it to?". Many UK habitats we see as being pristine are often man-made. The southern moors - Exmoor and Dartmoor - were (iiuc) largely forested but was cleared in the mesolithic for farmland. They're now important habitats in their own right and reforesting them seems unlikely to be feasible or sensible. What land we choose to restore and what we restore it seems a fairly complicated question. We've been farming the land for so long, it's hard to know what's 'natural' any more.

Re: HS2

Posted: Mon Feb 08, 2021 11:12 pm
by plodder
Bird on a Fire wrote:
Mon Feb 08, 2021 3:09 pm

I do understand habitat creation and connectivity, which is why I've focussed purely on those aspects throughout the thread. HS2 is doing it very badly, creating a precedent that road- and house-builders will be able to rely on in court unless the legislation changes for the better (which it won't under the current government).
So essentially because HS2 is following planning law and doing everything asked of them by the regulators, and you don’t like the regulatory stance, you’re happy to turn a blind eye to all the misinformation and rubbish being spoken about a hugely significant and important environmental project, on the off chance that other sh.t projects will have to operate under a different regulatory stance. I’ve reread the thread and i’m pretty sure that’s what it boils down to.

Re: HS2

Posted: Tue Feb 09, 2021 7:39 am
by plodder
HS2 responding to the woodlands issue: not sure what’s going on here. The thread contains examples of woodlands some distance from the route that are in the list of 108 “damaged or destroyed” woodlands.

https://mobile.twitter.com/HS2ltd/statu ... 7824304128

Re: HS2

Posted: Tue Feb 09, 2021 10:51 am
by Bird on a Fire
The original list just says "affected". I agree that anyone claiming they're being destroyed is wrong.

As you know, fragments of ancient woodland on their own don't function as habitats. They need to be connected up with other areas of woodland. What HS2 is doing is severing those fragments and not joining them up again. That's what the Wildlife Trusts and Woodlands Trust are concerned about.

HS2's ecology team definitely understand this, so putting out tweets that ignore the real issue isn't massively encouraging.

Re: HS2

Posted: Tue Feb 09, 2021 10:59 am
by Bird on a Fire
plodder wrote:
Mon Feb 08, 2021 11:12 pm
Bird on a Fire wrote:
Mon Feb 08, 2021 3:09 pm

I do understand habitat creation and connectivity, which is why I've focussed purely on those aspects throughout the thread. HS2 is doing it very badly, creating a precedent that road- and house-builders will be able to rely on in court unless the legislation changes for the better (which it won't under the current government).
So essentially because HS2 is following planning law and doing everything asked of them by the regulators, and you don’t like the regulatory stance, you’re happy to turn a blind eye to all the misinformation and rubbish being spoken about a hugely significant and important environmental project, on the off chance that other sh.t projects will have to operate under a different regulatory stance. I’ve reread the thread and i’m pretty sure that’s what it boils down to.
We both know NE have had their budget cut to the bone. I wouldn't be surprised if there's been a lot of political pressure surrounding HS2, but if they're actually happy with this, NE are sh.t too.

It may within the letter of the law, but clearly contradicts policy. Government projects, especially high-profile environmental ones, should obviously be supporting environmental policy rather than undermining it.

If you want to talk about specific bits of misinformation by all means link to some. The only misinformation posted here so far was that tweet claiming the Wildlife Trusts have said 108 ancient woodlands will be destroyed, when they actually haven't.

There are sound ecological reasons to be unhappy about the current plans, and sensible proposals to address the issues. I'm personally much more interested in that discussion than getting annoyed about random anonymous dickheads on twitter emotionally exaggerating stuff.

Re: HS2

Posted: Tue Feb 09, 2021 11:14 am
by Bird on a Fire
Fishnut wrote:
Mon Feb 08, 2021 10:04 pm
discovolante wrote:
Mon Feb 08, 2021 9:41 pm
Fishnut wrote:
Sun Feb 07, 2021 9:51 pm

Thanks :) Downloading now
You will not be surprised to hear that Reforesting Scotland also has a lot of discussion about er, reforesting Scotland:
https://reforestingscotland.org/whats-new/ including the tensions between the various interests people have. Its relevance to someone who lives in the south of England might be limited but there are probably some general principles and themes that can be carried over to other environments. Probably.
Oh, thanks!

Speaking from a position of "just enough knowledge to embarrass myself" the question seems to not be so much "do we restore an environment?" but "what do we restore it to?". Many UK habitats we see as being pristine are often man-made. The southern moors - Exmoor and Dartmoor - were (iiuc) largely forested but was cleared in the mesolithic for farmland. They're now important habitats in their own right and reforesting them seems unlikely to be feasible or sensible. What land we choose to restore and what we restore it seems a fairly complicated question. We've been farming the land for so long, it's hard to know what's 'natural' any more.
Yes, there's definitely a case to be made for having a vision of what we'd like the countryside to look like, and setting goals to achieve that.

Scientists can also help. For example, if we want to maintain populations of woodland specialist species, we need to preserve every last remaining scrap of ancient woodland as a priority, but also connect them up with other areas of woodland, and finally consider reforesting new areas (preferably connected to existing patches). Wetlands similarly would benefit from preservation, connection and expansion.

Compared with what I've seen elsewhere, the biggest problem in the UK is fragmentation. Loads of protected sites are absolutely tiny, with no statutory requirement to create and maintain connections between them. So the country has designated hundreds of separate areas of populations slowly going extinct. The country could really do with some large-scale areas where human impacts are minimised, but doesn't at the moment. Even the UK's National Parks are full of intensive grazing, non-native forestry plantations, managing moorlands for shooting, and all sorts of other damaging stuff that wouldn't be legal anywhere else.

I think the mesolithic is long enough ago not to worry about too much ;) Most of the issues with farmland derive from post-war intensification: the loss of hedges, field margins, fallow fields, massive increases in grazing stock density, increased biocide use, drainage, deep ploughing, etc. (Some of those things always happened - especially drainage - but have become more widespread and more efficient).

There is space in the country. Deer-shooting estates alone make up an area bigger than Yellowstone, and contribute far less to the economy than wildlife tourism would. In the crowded southern lowlands, wilderness would be harder to achieve so we'd have to be a bit smarter about joining things up. It requires some vision, some effort, and some challenging of powerful wealthy interests.

The Lawton Review ("Making Space for Nature") is probably the best read on this https://www.gov.uk/government/news/maki ... shed-today It was published a decade ago, but has yet to actually be implemented in terms of specific legislation. There are guidelines, but even the government itself doesn't follow them.

Re: HS2

Posted: Tue Feb 09, 2021 11:46 am
by plodder
Bird on a Fire wrote:
Tue Feb 09, 2021 10:51 am
The original list just says "affected". I agree that anyone claiming they're being destroyed is wrong.

As you know, fragments of ancient woodland on their own don't function as habitats. They need to be connected up with other areas of woodland. What HS2 is doing is severing those fragments and not joining them up again. That's what the Wildlife Trusts and Woodlands Trust are concerned about.

HS2's ecology team definitely understand this, so putting out tweets that ignore the real issue isn't massively encouraging.
The wildlife trusts regularly phrase it as "destroyed or damaged" rather than "affected" which could mean the trains are audible from a mile away.

They are taking a partisan stance in order to whip up public opinion. The facts may be buried deep within technical reports, but the press officers are having a field day - I'd imagine donations are through the roof. A bit like those sciencey press releases we all enjoy laughing at.
HS2 decision will destroy precious wild places
Today the Government gave the green light to the High Speed 2 rail project, without acknowledging the devastating impact on the hundreds of precious wild places and the wildlife that depends on them – that lie in the path of the route. The Wildlife Trusts recently published a report evidencing the vast scale of the destruction and impact that HS2 will cause to nature.
Today’s announcement means that it is more critical than ever that the whole project is redesigned – before HS2 creates a scar that can never heal.
https://www.wildlifetrusts.org/news/hs2 ... ild-places

Or
HS2 will destroy or irreparably damage five internationally protected wildlife sites, 693 local wildlife sites, 108 ancient woodlands and 33 legally protected sites of special scientific interest, according to the most comprehensive survey of its impact on wildlife.
https://www.theguardian.com/uk-news/202 ... tes-report

Not "affect".

Re: HS2

Posted: Tue Feb 09, 2021 11:50 am
by Bird on a Fire
It is accurate to say that HS2 will destroy and damage a lot of wildlife sites though. It's the "destroy 108 ancient woodlands" that's misleading. (You do realise not every wildlife site is a designated ancient woodland?!)

Agree that the Guardian has spun that report a bit too far, there.

Re: HS2

Posted: Tue Feb 09, 2021 12:09 pm
by Bird on a Fire
Here's what the RSPB say:
At the time it was being consulted on, we did not consider that HS2 Phase 2 (the northern extension via two routes to Manchester and Leeds) had such significant impacts on biodiversity of national or international importance that it would trigger intervention by the RSPB.

However, eight years on, it does not look like any of the principles of the Right Lines Charter have been followed in the way that we hoped for. We share the concerns of our colleagues at the Wildlife Trusts and Woodland Trust about the impacts on local wildlife; 108 ancient woodlands are at risk, as well as many other local wildlife sites. Irreplaceable habitats aside, HS2 has committed to achieving no net loss of biodiversity, but is unlikely to achieve even this. At a time when the Government is asking housing developers to provide at least 10% biodiversity net gain (and we think it should be even more), this is completely inadequate.
https://www.rspb.org.uk/our-work/our-po ... h-speed-2/

Re: HS2

Posted: Tue Feb 09, 2021 12:15 pm
by Bird on a Fire
Also worth reading their full letter to the DoT:
We have noted the claim that “there is a plan to ensure that this is one of the most environmentally
responsible infrastructure projects ever delivered in the UK”. This is a welcome ambition, but sadly we feel
there is a wide gap between ambition and reality for HS2 and its impact on nature. We believe HS2 as
currently planned will cause a significant net loss of biodiversity and that the Government’s claim is unjustified.
The RSPB and the wider environment sector have worked hard over many years to engage with HS2 Ltd over
the mitigation and compensation package. However, on many important issues our advice has not been
followed. For example:
• Along with the Barn Owl Trust and four local Wildlife Trusts, we have said HS2 Ltd’s barn owl mitigation
plan will not work. We believe HS2 phase 1 will eventually kill a nationally significant number of barn owls,
and phase 2 will merely add to that toll.
• Much of the mitigation for bats in Buckinghamshire has been challenged by independent academic experts
as inadequate and ineffective. For example, Bechstein’s bats are one of the UK’s rarest mammals and
prefer mature woodland - newly planted hedgerows and woodlands will not help these animals.
• HS2 Ltd’s own figures currently suggest that Phase 1 will lead to a 3% net loss of replaceable habitats, and
17% loss for Phase 2a - thereby falling short of HS2 Ltd’s own objective of achieving no net loss of
biodiversity. This is after discounting unavoidable damage to irreplaceable ancient woodland, which cannot
be compensated for.

We do not think this is good enough. However, we are still prepared to work with HS2 Ltd, the Department for
Transport and other stakeholders to help make HS2 fit for purpose in the context of a climate and ecological
emergency. But, for us to justify our continued engagement we would need some assurances of the
Government’s positive intent. These are:
1) Each phase of HS2 must deliver a net gain for nature in its own right, as good or better than your
Government’s expectations for other forms of development. This would be in line with the recently-
launched National Infrastructure Committee Design Principles for National Infrastructure. We believe HS2
should strive for a minimum of 10% net gain but ideally go further, and deliver what nature needs which is
to begin to recover from its low baseline. There is no reasonable justification why major infrastructure
projects should be exempt from delivering net gain, especially as their fragmentation effects on Nature
Recovery Networks are likely to be profound. We applaud the East West Rail company for voluntarily
committing to delivering net gain, at least within the Bedford-Cambridge section. We call on you to ensure
that HS2 and other major infrastructure projects do the same, or even better.

2) It must be accepted that “compensation” for the loss of ancient woodland is not possible, no matter how
many new trees are planted. We understand that irreplaceable habitats have been excluded from the net
loss calculations, long after we argued for it during the consultations on the Environmental Statement and
our Hybrid Bill petition. More than that, HS2 Ltd must deliver the best mitigation package for irreplaceable
habitats that is possible given the state of the art.

3) As a matter of policy, HS2 and other major infrastructure projects must apply the same principles of the
ecological mitigation hierarchy the NPPF requires local authorities to follow. For example, when accounting
for impacts on nature in phases 2a and 2b, HS2 Ltd must not conflate mitigation and compensation, and
stop concluding that after taking compensation into account there are no residual adverse impacts on (for
example) designated sites and ecological networks.

4) A clear and independent audit of the carbon footprint of HS2 is needed, taking into account its construction
and lifetime performance, and predicted effects on other transport sectors including road freight and
aviation. The environmental sector has been criticised for not acknowledging the alleged carbon-saving
benefits of HS2 while drawing attention to its biodiversity impacts. And yet, the Oakervee Review merely
notes the potential for HS2 to contribute to a reduction in carbon emissions across the whole transport
sector. Unfortunately, many of the policy initiatives needed to bring this about do not yet exist - notably, an
integrated government strategy to encourage people to shift to greener transport modes. Until such
measures are put in place there is no guarantee that HS2 will bring about a major shift away from more
polluting forms of transport instead of fuelling further unsustainable growth and travel demand, and no firm
basis to claim otherwise.

5) Linked to the above point, the Government needs to show how the landmark ruling over the third runway at
Heathrow airport issued on 27 February 2020 will be applied to strategic design choices made over HS2.
This includes the Government’s continued unwillingness in this and other schemes to accept that Strategic
Environmental Assessment has a critical role to play in considering and addressing environmental issues.
This includes the implications of policies or plans for meeting carbon reduction targets.

6) Finally, we need to see HS2 Ltd and their contractors behaving responsibly and going beyond the letter of
the law when it comes to avoiding destruction of active nests of breeding birds and mitigating impacts on
other protected species. There can be no reason for large-scale clearance of trees, hedgerows and
woodlands in the breeding season except for Government pressure on HS2 Ltd to deliver the project
quickly. The RSPB advises HS2 Ltd and their contractors to avoid clearance work between early March
and the end of August.

We have already witnessed ethically and practically doubtful tactics such as Harris hawks being used in an
ill-informed attempt to deter birds from nesting in a wood, and notification to the Woodland Trust that
undergrowth from other ancient woodlands will be cleared as another tactic to try to deter birds from
nesting in places where later they might be destroyed. Such activities raise concerns about the
professional competence of the ecological advisors HS2 Ltd is using and they certainly cannot be held up
as environmentally responsible best practice.

We will consider any attempt by HS2 Ltd’s contractors to claim that destruction of active birds’ nests was
not intentional and was the incidental result of a lawful operation that could not reasonably have been
avoided, to be legally and morally dubious. Local people are watching events on the ground with keen
eyes and the RSPB is bound to advise them to contact the police when an offence under the Wildlife &
Countryside Act 1981 is suspected.

Unless we see clear commitment from the Government and HS2 Ltd on the above points the RSPB cannot
justify further positive engagement with you to try to improve this project, not least to our 1.2 million members,
many of whom are deeply concerned about HS2 and other major infrastructure projects. Far from being “one
of the most environmentally responsible infrastructure projects ever delivered in the UK” HS2 will stand as an
example of worst practice in the face of the climate and ecological emergency, one that cannot be repeated as
other major infrastructure projects are brought forward.
In the worsening climate and ecological emergency, it will be impossible to achieve the ambitions in the 25-
year Environment Plan if major infrastructure projects such as HS2 are allowed to do this amount of damage
as well as proceeding without a full understanding of the carbon footprint.

Re: HS2

Posted: Tue Feb 09, 2021 3:04 pm
by plodder
The RSPB are generally a lot more sober - they have to be as they have about a million members so they don't tend to take shouty stances.

In terms of shoutiness (loudest first) my list is:

XR
Green Party (new entry)
Greenpeace
Wildlife Trusts
FOE
RSPB

But what you don't see is the RSPB publicly undermining XR, for example. They each know they have a role to play.

Re: HS2

Posted: Tue Feb 09, 2021 9:55 pm
by Sciolus
HS2 don't make it easy to download the route, but I eventually found it here file. Ancient woodland can be downloaded here file.

I count that the route passes through 20 AWs London--Birmingham and another 6 Brum--Rugeley. That's for the 20 m width in the shapefile, which may or may not include land take during construction, I don't know. It passes within 200 m* of 72 AW units in that length. Someone more competent at GIS can doubtless extract the areas involved.

*An arbitrarily chosen distance.

Re: HS2

Posted: Wed Feb 10, 2021 2:40 pm
by plodder
For those of us without GIS (or even with) I suppose we’re getting into the details of “affected” vs “damaged” and how this is modelled, and what assumptions are being made, and what data backs it up, and how good the science is and all that messy coalface stuff.

Re: HS2

Posted: Wed Feb 10, 2021 3:21 pm
by Bird on a Fire
Noise above 55 dB is generally detrimental to wildlife populations. Looking at HS2's published contours it looks like 200m is a reasonable worst-case estimate of that.

You'd also need to include consideration other habitats in the area. If you leave the patch of designated ancient woodland alone, but sever the hedge/shelterbelt/whatever connecting it to another woodland, you've still damaged it.

AIUI those kinds of effects are very significant, but it won't show up in these kinds of naive "x m2 of designated habitats". It inaccurately minimises the impact, which is why conservationists aren't using that approach but HS2 proponents keep repeating it as loudly as possible like it means something. Talking right past each other, they are.

Re: HS2

Posted: Wed Feb 10, 2021 4:25 pm
by El Pollo Diablo
According to this noise comparison chart, 55dB is equivalent to a common household refrigerator. I am not arguing at all against that level of noise being an issue if you say it is, but two things I would say are that (a) it'll take a hell of a lot more than 200m to cancel out the noise of a passing train (especially considering that at night I can hear train horns from two miles away, across the other side of town); and (b) everything else we do as humanity, from flying planes to driving cars to Welsh male voice choirs to allowing babies to cry will have a similar impact.

I'm sure as well that there are differences between the sort of background whine of constant car traffic next to a motorway or major road (both night and day), compared to the loud noise of a passing train every 100 seconds that HS2 will bring, but which will stop overnight. It'd be interesting to understand the differences that those things have on wildlife.

Re: HS2

Posted: Wed Feb 10, 2021 4:39 pm
by El Pollo Diablo
I found this paper, in the seemingly relevant journal Railway Ecology, which suggests that railway environments can have interesting effects - the noise is certainly an impact, and particularly so on birds compared to insects, mammals, amphibians and reptiles. However, at the same time, some species are able to learn to live with the noise, and railway environments tend to also offer a useful environment for them to live and breed in. For small prey animals, the noise can drive out predators, which is obviously beneficial for them (though not necessarily for local ecology, obviously).
Certain bird species seem to ignore railway disturbances. For example, brants (Branta asp.) seem to disregard the trains passing 50 m away (Owens 1977). Likewise, although Waterman et al. (2002) found a negative effect on the density of birds on railways in general, they did not find differences in bird density between quiet and busy railways. Indeed, there is evidence that bird species tolerate the railway disturbance due to the attractiveness of numerous railway-related features. Species whose predators show negative responses to train disturbance may also benefit from the railway vicinity (Rytwinski and Fahrig 2012). Railway verges may create edge effects that can increase biodiversity. In fact, special microclimates—thanks to different temperatures or insolation and new habitat availability along the edges—can enhance habitat heterogeneity in homogeneous landscapes (Delgado et al. 2007). In turn, these new habitats may improve resting and foraging opportunities for some bird species (Morelli et al. 2014). Also, railways can be a useful source for gastroliths’ digestive purposes, and a source of sand bathing locations used by birds to clean the feathers. Ghosh et al. (2010) showed that apparently due to the food availability, house sparrows (Passer domesticus) adapted to loud noise (between 35 and 95 dB), being undisturbed by passing trains at the railway station study site. Equally, Li et al. (2010) observed the abundance and richness of seven ground-dwelling bird species, namely the Tibetan ground tit (Pseudopodoces humilis), Tibetan lark (Melanocorypha maxima), horned lark (Eremophila alpestris), white-winged snowfinch (Montifringillla nivalis), plain-backed snowfinch (M. blandfordi), white-rumped snowfinch (M. taczanowskii), and rufous-necked snowfinch (M. ruficollis). They found greater numbers of individuals of these species near the Qinghai-Tibet railway (less than 300 m) than farther away (from 300 to 1,200 m), probably due to verges provide nesting sites and foraging opportunities.
And that
the non-continuous nature of the noise near railways due to the intermittent flow of train traffic may constitute the main reason that some birds ignore the railway. This was hypothesized by Wiacek et al. (2015) to explain the greater abundance of the breeding community of woodland birds near a busy railway line in Poland when they assessed the effect of noise at three different distances from the track (30, 280, and 530 m). Species with low frequency calls, such as the wood pigeon (Columba palumbus) and common cuckoo (Cuculus canorus), also occurred in large numbers near railways. Other bird species also seem to ignore the railway disturbance. For example, more than 90% of bald eagle nests were built near human infrastructures, including railways that had more than 1,000 railcars going by each day (Mundahl et al. 2013).
Though that last sentence contrasts with an earlier one in the paper:
For example, noise emission from railway traffic has a negative effect on the density of all meadow birds in the Netherlands (Waterman et al. 2002). The threshold noise level from which densities were affected was around 42–49 dB(A) for the black-tailed godwit (Limosa limosa), skylark (Alauda arvensis), and garganey (Anas querquedula) (Waterman et al. 2002). There was also evidence that successful bald eagle (Haliaeetus leucocephalus) nests were farther away from highways and railways than unsuccessful ones (Mundahl et al. 2013).

Re: HS2

Posted: Wed Feb 10, 2021 5:50 pm
by Bird on a Fire
Cool paper, thanks! I've been reading a lot of noise stuff lately but haven't found much for trains. Will have a read.

55 dB sounds like a lot for a "household fridge" - mine doesn't make much noise at all. For reference, 55 dB is the level above which it's considered "noise pollution" and about 65 dB it causes physiological stress, according to the WHO. (This is referenced in the Railway Ecology chapter).

Experimental papers are thin on the ground, but there's stuff like these (simulated traffic noise) or this (airhorn) all seemingly showing effects from 55 dB. There's other observational studies, but generally conducted after the noisy_thing had been in place a while, so only studying the already-habituated community. Nevertheless there's studies like this showing a reasonably severe energetic cost to disturbance (from aircraft) even after the airport had been in place for decades.

Railway habitats certainly can be valuable for some species, as you say. Unfortunately a lot of species of conservation concern are especially sensitive to disturbance, with benefits accruing to more generalist species. Swapping an ancient-woodland community for a railway-siding community would be a pretty drastic change, even if both are valuable habitats in their own right.

I don't think the noise would be a huge massive disaster or anything, but there are very few patches of ancient woodland left and some of their specialist species are already on their last legs because, as you say, most of the countryside is already filled with pervasive impacts. Nature in the UK is in seriously dire straits, with just about every indicator heading straight down the pan. So I think it's pretty reasonable for people to get cheesed off about impacts on the last fragments of irreplaceable-ish (takes a few centuries) habitat.