The latest instalment of our weekly series, in which we use the Centre for Cities’ data tools to crunch some of the numbers on Britain’s cities.

It’s the 21st century. We get it.

Climate change is an existential threat, global warming is bad, carbon emissions are largely to blame, and if we don’t do something terribly drastic soon, everything we know and love will perish in a Hollywood-movie orgy of rising sea levels, cataclysmic extreme weather events, and men looking seriously at enormous banks of screens.

And yet we carry on, firing up fossil fuel power stations, driving petrol-chugging cars, and producing lots of stuff in emission-belting factories.

Cities, inevitably, are a big part of this. They are congregations of a lot of people, consuming resources, driving to work, and working in CO2-emitting offices, warehouses, and factories.

But some are worse than others. Londoners, who are less likely to sit in badly polluting cars because they have the wonderful tube, emit less CO2 per capita. There may be loads of them, but relative to how many there are, the emissions aren’t that terrible.

Swansea and Middlesbrough, however, are terrible.

Hover over the dots to see the figures for individual cities. Graphic: Centre for Cities.

By the most recent figures in 2014, CO2 emissions per capita stood at 26.78 tons in Swansea, and 26.22 tons in Middlesbrough. For context, the national average is 6.25 tons, and the third most emitting city is Newport, which belts out 7.46 tons per capita, while London only manages a paltry 4.4.

That’s not a particularly recent change, either. Swansea and Middlesbrough have led the field every single year, by quite some margin, since the start of the Centre for Cities’ data in 2006.

Why? Steel, basically.

Middlesbrough hit it off as a big booming iron town. In the Victorian age amid the throes of the industrial revolution, Middlesbrough was known as ‘Ironopolis’, and Dorman Long – a successor firm to one of the big beasts of steel production of the industry – built the Sydney Harbour Bridge, became a major part of the nationalised British Steel Corporation, and only ceased producing steel on Teesside in 2015, not yet covered by the data we have available.

Up until 2010, the area also had a steel plant run by Corus, which later became Tata Steel, the company that got caught up in a steely face-off last year over production in Port Talbot – part of the conurbation of, you guessed it, Swansea.

That big fat steel plant near Swansea. Image: Grubb via Wikimedia Commons

Both have strong power production bases, too. The Swansea area includes Baglan Bay, a bit fat gas-fired power station that has been trundling away since 2003, while Middlesbrough has a phenomenal four active fossil fuel power stations running.

As the area is on the edge of one of the largest historic coalfields in the country, that makes sense, but for a metro area with just under 400,000 people, it seems a little excessive.

But what seems strange is the change in these emissions. Not only are Swansea and Middlesbrough the most CO2-emitting cities in the country, they’re also getting worse.

Looking at the actual change in emissions per capita from 2010 to 2014, you can see that both cities are the only places in the countries that are polluting more.

Top five gross changes in emissions per capita 2010-2014. Click to expand. Image: Centre for Cities

Middlesbrough is up by 8.33 tons, while Swansea is up by 0.13 tons.

Top ten percentage changes in emissions per capita 2010-2014. Click to expand. Image: Centre for Cities

By percentage, the figures for Middlesbrough are pretty astonishing – it polluted 46.58 per cent more in 2014 than it did in 2010.

But it’s a complicated game of numbers.

Top ten percentage changes in emissions per capita 2005-2014. Click to expand. Image: Centre for Cities

If you look right back to the earliest data, from 2005, you can see that Swansea is the only city that emitted more per capita in 2014 than it did almost a decade earlier – up by 4.44 per cent, or 1.14 tons per person.

But Middlesbrough’s not far behind. By percentage change, it has had the smallest decrease in emissions, churning out 16.38 per cent less CO2 per person than it did in 2005.

Top ten decreases in emissions per capita 2005-2014. Click to expand. Image: Centre for Cities

But because it was so far ahead to start off with, its change is also the biggest gross fall – emitting 5.13 tons fewer per person in 2014 than in 2005.

The picture is unclear. Steel manufacturing in the UK is in a crisis period, with deals and government interventions only a short-term blip in a long-term story of decline, closure, and job losses.

As more data becomes available, and the futures of Britain’s steel plants become apparent, it’s likely that all UK cities will be emitting less CO2 per person year-on-year – and the gradual decommissioning of coal and gas-fired power stations and replacement with clean, shiny, cuddly renewable energy stations (like the big fat tidal power station they keep talking about building in South Wales) will only further that effect.

For now though, tough luck Swansea and Middlesbrough – we’re all pointing our judgmental green fingers at you. 

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