Silvertown Tunnel: stop digging

Silvertown protest
Greenwich and Bexley Green Party
The UK Government cannot claim to be dealing with climate change and build the Silvertown Tunnel.

We need to take them on, one climate-threatening, pollution-causing construction project at a time.

The Silvertown tunnel, London’s largest infrastructure project, is incompatible with preventing dangerous climate change, a report released today shows. 

Building the £1.2 billion tunnel will help drive London’s greenhouse gas emissions upwards, and exacerbate serious air pollution problems, the report says.

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The report, entitled The Silvertown Tunnel is in a Hole, so Stop Digging, is published by the Transport Action Networkthe Stop the Silvertown Tunnel coalition, the local Speak Out Woolwich campaign group and Extinction Rebellion Greenwich – in the week when engineering work for the tunnel has begun.


Boreholes are reportedly being driven under the River Thames for power cables needed for the tunnel, which – if it is built – would run alongside the Blackwall Tunnel at north Greenwich.

The start of construction work on the tunnel could be delayed, though, due to Covid-19 pandemic – offering a fresh opportunity to campaigners to stop it all together.

The conclusions of the Stop Digging report – that the tunnel should be cancelled and London’s transport strategy brought in line with carbon budgets – are supported by a long list of groups and individuals, including the New Economics Foundation, trade unions, environmental and residents’ groups, prominent climate scientists and traffic researchers, and local representatives of the Labour, Green and Liberal Democratic parties.

We need to take them on, one climate-threatening, pollution-causing construction project at a time.

Transport for London (TfL) signed contracts with a private consortium to build the tunnel in November last year. Since then, the Covid-19 pandemic has turned urban transport systems inside-out, caused transport researchers to envisage a permanent reduction in traffic volumes, and led Chris Stark, the UK Committee on Climate Change chief executive, and Edmund King, president of the AA, to call for road investments to be switched to broadband networks. But the Greater London Authority (GLA) presses on with the tunnel regardless.

The tunnel project has been resisted, since it was first mooted nearly a decade ago, by local campaign groups who fear the disastrous effect of air pollution, especially on children. The borough of Newham, on the north side of the tunnel site, has the highest level of PM2.5 particulates in the UK, according to research supported by the British Heart Foundation.

Newham also has among the highest proportions of black, Asian and minority ethnic people in the country, and among the highest levels of poverty. The pollution levels in Greenwich, on the south side, are slightly lower – but still way above legal limits.

Carbon budgets

The campaign to stop the tunnel gained momentum in December 2018, when London mayor Sadiq Khan declared a “climate emergency” – as did the UK parliament and other local authorities – in response to the school students’ climate protests and street actions by Extinction Rebellion. 

Today’s report suggests that the “emergency” declaration is not worth the paper it is written on – not only because, by TfL’s own estimates, construction work would pour the same amount of greenhouse gases into the atmosphere as 700 trips of 900+km each by a Boeing 737-400, but also because the tunnel is sure to produce extra traffic over the long run. 

The London transport strategy, while including measures to support cycling and walking, retains pride of place for cars and trucks for the indefinite future ... and is based on decarbonisation scenarios that miss targets for tackling dangerous climate change by a long way.

The Stop Digging report compares the “carbon budgets” (that is, the amount of carbon emissions that can safely be tolerated) worked out for London by the Tyndall Centre for Climate Research, those used in the GLA’s Environment Strategy, and the emissions levels assumed by TfL’s paperwork for the tunnel project. 

The Tyndall Centre says that London’s greenhouse gas emissions need to be cut by 12.2 percent per year, if dangerous global warming levels are not to be breached. These reductions are much steeper than those proposed in GLA documents. Tyndall’s carbon budgets for the years 2023-27 are little more than half of the budgets the GLA allows.


But the comparison between the GLA’s scenarios and those in TfL’s tunnel documents suggest that the authority is not taking even its own targets seriously. The GLA projects that emissions will fall from 8.22 m t of CO2 equiovalent in 2015 to 3.97 mtCO2e in 2036, a reduction of more than half – whereas the Silvertown tunnel environment statement presents scenarios implying a reduction of less than one tenth by 2036. And presumably there are executive and investment decisions being taken each day on that basis.

The GLA has developed considerable skill at talking “green” while walking carbon.

The Stop Digging report also places a giant question mark against the claim by GLA spokespeople and Labour councillors who support the tunnel project that it would not increase the overall level of traffic. Against this it sets the “induced traffic” concept – simply, that more roads produce more traffic – developed by transport researchers over several decades. 

TfL says its models show that “induced traffic” can be avoided by road tolls. Today’s report says the assumptions on which the models are based have “perversely minimised” the induced traffic effect, and that the experience of other road projects, including the next road crossing upstream, the Dartford crossing, has not been taken into account.

As author of the report and a participant in efforts to lobby the GLA, I have been struck by the chasm between politicians’ statements about climate and their actions.


In the real world that we live in, TfL hopes later this year to bring in earth-moving equipment to start building a tunnel that will give another push to the more roads, more traffic spiral.

Were the tunnel to be built, cars and trucks will be favoured, public transport made more expensive and the potential for transforming urban transport – so evident in London during the Covid-19 lockdown – delivered a dreadful blow.

In this real world, new road networks would be piled on old ones, the car-based transport system would expand, and greenhouse gas emissions would go hurtling still faster towards climate disaster. T

he GLA would be every bit as culpable as car manufacturers who talk about electric vehicles – which anyway have limited potential in terms of reducing greenhouse gas emissions – while increasing the sales of SUVs. 

In a parallel world, mayor Sadiq Khan declares London to be leading the world on climate change, and issues a statement with other mayors that the recovery from Covid-19 "should not be a return to ‘business as usual’". The GLA proclaims an environment strategy that will produce “carbon neutrality” – which on inspection turns out to be full of holes.


Campaigners in south east London tried to bridge the gap between these worlds. In July last year, 150 of us gathered at a meeting organised by the Speak Out Woolwich group. Deputy mayor Heidi Alexander, who is responsible for transport policy, was invited, but was too busy to attend, to send someone in her place or to respond to emails. 

After months of lobbying, Alexander grudgingly agreed to spend 45 minutes meeting a delegation from the Stop the Silvertown Tunnel coalition. She treated with disdain the presentation of research, put together by professionals, showing that the GLA and TfL climate scenarios were way out of line. She was not interested.

Greta Thunberg and the school students are right: this gulf between rhetoric and reality needs to be met with direct action. Politicians with two-faced “environmentally friendly” paperwork, as well as the actual climate deniers, are exacerbating the dangers caused by decades of rapidly-mounting fossil fuel use and the resulting greenhouse gas emissions.

We need to take them on, one climate-threatening, pollution-causing construction project at a time.

This Author 

Simon Pirani is author of Burning Up: a global history of fossil fuel consumption, and a Greenwich borough resident. 

Image: Greenwich and Bexley Green Party.

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