London's Tube has been running so long it's literally raising the temperature of the earth around it

Londoners swelter on the Central line during the heat wave of 2003. Image: Getty.

“Why is the tube so hot?” is one of those questions Londoners find themselves asking a lot during the three or four days a year when the city’s weather isn’t completely bloody miserable. But it’s not something to which I’ve ever given much thought. Lot of people, enclosed space – the reasons are obvious, surely?

Except, not every underground railway in the world has this problem. And once upon a time, London didn’t either: when the Bakerloo line first opened, posters suggested it was a good place to keep cool on a hot day, an idea that’s clearly nonsensical in 2017.

And then, from the Twitter feed of occasional CityMetric contributor @LeftOutside earlier*, I learned something genuinely amazing:

My mind, as the kids say, is blown.

And it’s true. In 1900, according to this fascinating article in Rail magazine, the ambient heat of the earth surrounding the tunnels – clay, mostly – was around 14°C. In the height of summer, the tunnels were indeed colder than the air above, so it made sense to travel by tube to cool down.

The problem is – trains full of people tend to give off heat. According to this article from a 2007 edition of Plant Engineering magazine, the vast majority (89 per cent) of that heat comes from the train itself (the friction during braking is the big one), 7 per cent from passengers and 4 per cent from “Tunnel support systems”.

What happens to this heat? On the sub-surface lines – basically, those which share tracks with the Circle – it’s not too big a problem. The tunnels are close to the surface, so often emerge into the light for brief periods (Barbican, South Kensington and Edgware Road are all above ground). They also have plenty of ventilation shafts. The heat has somewhere to go.

The deep tubes, though – the ones which are literally tunnels bored through the ground – are more problematic. Most of them are old, so were built before anyone realised heat would be a problem, and don’t come with enough ventilation shafts to solve it. The air is trapped. And so, the heat is absorbed by the walls, and the earth behind them.

In 1900, as noted above, the average ambient temperature was 14°C. Some 117 years and millions of trains later, it can be anywhere between 20°C and 25°C.


 Let’s just say that again: London has been running tube trains so long that the ground beneath parts of the city is now as much as 10°C hotter than it was in 1900.

One result of this is that the earth has become much less effective at absorbing the excess heat. That means the tunnels themselves have heated up, too. A lot: air inside them can often reach as high as 30°C. You’ve probably noticed this is you’ve been on the tube recently.

For the last decade or so, Transport for London has been looking for solutions to this. Some of them involve increasing the capacity of existing ventilation systems (lack of space above ground means it’s extremely difficult to build new ones). Others involve adding systems which circulate water to cool the air. Yet other options involve things like more efficient braking systems, on the grounds that if you put less heat in, you have less to take out.

Experimental air coolers on the Victoria line. Image: Oxyman/Wikipedia Commons.

It’s clear that there’s no easy solution, however: in 2003, then London mayor Ken Livingstone offered a prize of £100,000 to anyone who could come up with fresh ideas. Nobody could think of anything TfL wasn’t already trying, and the prize went unclaimed.

The upside to this story is that other cities have learned from London’s mistakes, and ensured that ventilation systems are an integral part of new metro systems.

The downside is you’re likely to boil every time you get the Central line in summer for the foreseeable future.

*LeftOutside has since been in touch to tell me he was summarising another article, from the Ian Visits blog. I haven’t read that one – the above article is drawn from the two articles I reference, plus some bits from TfL. But in the name of politeness and an easy life I'm acknowledging its existence and adding a link. Read that too, if you like. 

Jonn Elledge is the editor of CityMetric. He is on Twitter as @jonnelledge and also has a Facebook page now for some reason. 

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Seven climate change myths put about by big oil companies

Oil is good for you! Image: Getty.

Since the start of this year, major players within the fossil fuel industry – “big oil” – have made some big announcements regarding climate change. BP revealed plans to reduce its greenhouse gas emissions by acquiring additional renewable energy companies. Royal Dutch Shell defended its $1-$2bn green energy annual budget. Even ExxonMobil, until recently relatively dismissive of the basic science behind climate change, included a section dedicated to reducing emissions in its yearly outlook for energy report.

But this idea of a “green” oil company producing “clean” fossil fuels is one that I would call a dangerous myth. Such myths obscure the irreconcilability between burning fossil fuels and environmental protection – yet they continue to be perpetuated to the detriment of our planet.

Myth 1: Climate change can be solved with the same thinking that created it

Measures put in place now to address climate change must be sustainable in the long run. A hasty, sticking plaster approach based on quick fixes and repurposed ideas will not suffice.

Yet this is precisely what some fossil fuel companies intend to do. To address climate change, major oil and gas companies are mostly doing what they have historically excelled at – more technology, more efficiency, and producing more fossil fuels.

But like the irresponsible gambler that cannot stop doubling down during a losing streak, the industry’s bet on more, more, more only means more ecological destruction. Irrespective of how efficient fossil fuel production becomes, that the industry’s core product can be 100 per cent environmentally sustainable is an illusion.

A potential glimmer of hope is carbon capture and storage (CCS), a process that sucks carbon out of the air and sends it back underground. But despite being praised by big oil as a silver bullet solution for climate change, CCS is yet another sticking plaster approach. Even CCS advocates suggest that it cannot currently be employed on a global, mass scale.

Myth 2: Climate change won’t spell the end of the fossil fuel industry

According to a recent report, climate change is one factor among several that has resulted in the end of big oil’s golden years – a time when oil was plenty, money quick, and the men at the top celebrated as cowboy capitalists.

Now, to ensure we do not surpass the dangerous 2°C threshold, we must realise that there is simply no place for “producers” of fossil fuels. After all, as scientists, financial experts, and activists have warned, if we want to avoid dangerous climate change, the proven reserves of the world’s biggest fossil fuel companies cannot be consumed.

Myth 3: Renewables investment means oil companies are seriously tackling climate change

Compared to overall capital expenditures, oil companies renewables’ investment is a miniscule drop in the barrel. Even then, as companies such as BP have demonstrated before, they will divest from renewables as soon as market conditions change.

Big oil companies’ green investments only produce tiny reductions in their overall greenhouse gas emissions. BP calls these effects “real sustainable reductions” – but they accounted for only 0.3 per cent of their total emissions reductions in 2016, 0.1 per cent in 2015, 0.1 per cent in 2014, and so on.


Myth 4: Hard climate regulation is not an option

One of the oil industry’s biggest fears regarding climate change is regulation. It is of such importance that BP recently hinted at big oil’s exodus from the EU if climate regulation took effect. Let’s be clear, we are talking about “command-and-control” regulation here, such as pollution limits, and not business-friendly tools such as carbon pricing or market-based quota systems.

There are many commercial reasons why the fossil fuel industry would prefer the latter over the former. Notably, regulation may result in a direct impact on the bottom line of fossil fuel companies given incurred costs. But climate regulation is – in combination with market-based mechanisms – required to address climate change. This is a widely accepted proposition advocated by mainstream economists, NGOs and most governments.

Myth 5: Without cheap fossil fuels, the developing world will stop

Total’s ex-CEO, the late Christoph de Margerie, once remarked: “Without access to energy, there is no development.” Although this is probably true, that this energy must come from fossil fuels is not. Consider, for example, how for 300 days last year Costa Rica relied entirely on renewable energy for its electricity needs. Even China, the world’s biggest polluter, is simultaneously the biggest investor in domestic renewables projects.

As the World Bank has highlighted, in contrast to big oil’s claims about producing more fossil fuels to end poverty, the sad truth is that by burning even the current fossil fuel stockpile, climate change will place millions of people back into poverty. The UN concurs, signalling that climate change will result in reduced crop yields, more waterborne diseases, higher food prices and greater civil unrest in developing parts of the world.

Myth 6: Big oil must be involved in climate policy-making

Fossil fuel companies insist that their involvement in climate policy-making is necessary, so much so that they have become part of the wallpaper at international environmental conferences. This neglects that fossil fuels are, in fact, a pretty large part of the problem. Big oil attends international environmental conferences for two reasons: lobbying and self-promotion.

Some UN organisations already recognise the risk of corporations hijacking the policy-making process. The World Health Organisation, for instance, forbids the tobacco industry from attending its conferences. The UN’s climate change arm, the UNFCCC, should take note.

Myth 7: Nature can and must be “tamed” to address climate change

If you mess with mother nature, she bites back. As scientists reiterate, natural systems are complex, unpredictable, and even hostile when disrupted.

Climate change is a prime example. Small changes in the chemical makeup of the atmosphere may have drastic implications for Earth’s inhabitants.

The ConversationFossil fuel companies reject that natural systems are fragile – as evidenced by their expansive operations in ecologically vulnerable areas such as the Arctic. The “wild” aspect of nature is considered something to be controlled and dominated. This myth merely serves as a way to boost egos. As independent scientist James Lovelock wrote, “The idea that humans are yet intelligent enough to serve as stewards of the Earth is among the most hubristic ever.”

George Ferns, Lecturer in Management, Employment and Organisation, Cardiff University.

This article was originally published on The Conversation. Read the original article.