How useful are the “connectors” on the Tube Map really?

All over the map. Image: TfL.

Connectors on the Tube Map are so often the unsung heroes of London’s transport network. Because of its advanced age, many of the lines in the capital snake around each other and interchange in ways that a modern transport system built from scratch would never even consider.

This means some pairs of stations are linked to each other, either through physical connections (like the walkway between Hackney Central and Hackney Downs) or more notionally, via the street (like Forest Gate and Wanstead Park). These links often necessitate a ‘connector’ on the Tube Map, like the big one between Bank and Monument. However, the sheer number of situations in which these humble connectors are applied means they often fall victim to problems.

Case in point: Camden. TfL’s recent public consultation into its upgrade of Camden Town Station noted that the new station, moved up onto Buck Street, will ease interchange with Camden Road Overground station, an option opened up by the new station’s increased capacity.

Image: TfL/CityMetric.

This is already an official “out-of-station interchange” (OSI), which means you can change from one station to the other and have it count as one journey rather than the usual two, and so are charged less on Oyster. You can find the full list of those here.

What stands out, though, is that the interchange TfL is so eager to improve in Camden is one they currently don’t bother to tell passengers about: it just doesn’t appear as a connection on the Tube Map. Unless a savvy passenger were to check, they wouldn’t know that the two Camden stations are only a three minute walk apart.

This is particularly scandalous, given the relative rarity of viable Overground – Underground interchanges. Why would TfL purposefully mislead passengers like this? Moreover, how do they determine when to connect two stations on the map? This is a question that deserves answers, but it feels like there aren’t any.

There is literally no firm way of telling which stations deserve a connector and which don’t

Let’s start with a simple assertion: all of the stations that are connected by underground tunnels are connected on the Tube Map. This, obviously, holds up.

There are also above-ground interchanges, like Clapham High Street/Clapham North, which are signposted and don’t use tunnels. Even though travellers have to enter and exit a ticket gate to use these interchanges, they still work because there is an OSI between them.

But half of the above ground OSIs aren’t shown on the map. And Camden is just the first of many.

Why did they bother with these two but not those two? Image: Tfl/CityMetric

There are lots of stations with OSIs that don’t connect on the Tube Map

A relatively well known example of this is Seven Sisters/South Tottenham; there have been complaints in the past that, despite being just as close together as the two Walthamstow stations to the east, these two don’t appear connected on the map.

But that is simply the first in a line of peculiar choices. Take Dalston Junction to Dalston Kingsland: only a three minute walk apart, they don’t get a visible connection either, even though a sprint between these two could make the difference when catching a train that’s just left Canonbury.

There are even interchanges that really should have an OSI but don’t get one

There are two stations in London called Bethnal Green. The two are about an eight minute walk apart, but they don’t get an out-of-station interchange. You might be wondering whether this is really so egregious: after all, eight minutes is surely a long time, and passengers could simply stay on either line and change at Liverpool Street.

Well, if eight minutes is a long time, then the trek required for the official interchange between Euston and King’s Cross is even longer. As for the change at Liverpool Street, this is a fair criticism – but enabling passengers to change at Bethnal Green would mean they could change without entering Zone 1, and save money as a result.

Double standards. Image: Google Maps/CityMetric

But that sets a dangerous precedent, doesn’t it?

Maybe. If we give the OSI between Euston and King’s Cross a thumbs-up, why doesn’t it get a connector? What about the other Central London stations with OSIs? There’s actually quite a lot of them.

The OSI between Warren Street and Euston Square is one example. A simple three minute walk along Euston Road could shave a minute or two off a journey. However, it feels like putting a connector on the Tube Map here would be overkill: travellers could simply walk from Euston instead. Giving all OSIs connectors on the Tube Map could just mean needless clutter and senseless route planning.

And with that, we reach a peculiar sort of conclusion: according to common sense, some stations, like in Camden and Bethnal Green, really need connecting up – but that same common sense could make Central London a complete mess on the Tube Map.


Method in the madness, then?

Yes. So perhaps the fact that there are no hard and fast rules for connecting stations on the Tube Map actually results in a cleaner end result than if such rules did actually exist. It’s also a much safer solution than connecting stations willy-nilly.

That’s because connecting two stations up on a map completely changes how travellers actually behave. Connecting stations like Dalston and Bethnal Green seems good on paper – but do the same in Camden this evening, and by tomorrow you’ll have dangerous crushes in station corridors, because too many people are trying to get from one station to the other.

The same might happen if you connected Euston Square and Warren Street on the map: the junction between Euston Road and Gower Street is not designed for masses of pedestrians crossing east to west.

So, if the system for determining which stations to connect appears non-existent in theory, but relatively sturdy in practice, what remains to be said?

Well, for one thing, Bethnal Green and Bethnal Green. Sort it out, TfL. 

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The IPPC report on the melting ice caps makes for terrifying reading

A Greeland iceberg, 2007. Image: Getty.

Earlier this year, the Intergovernmental Panel on Climate Change (IPCC) – the UN body responsible for communicating the science of climate breakdown – released its long-awaited Special Report on the Ocean and Cryosphere in a Changing Climate.

Based on almost 7,000 peer-reviewed research articles, the report is a cutting-edge crash course in how human-caused climate breakdown is changing our ice and oceans and what it means for humanity and the living planet. In a nutshell, the news isn’t good.

Cryosphere in decline

Most of us rarely come into contact with the cryosphere, but it is a critical part of our climate system. The term refers to the frozen parts of our planet – the great ice sheets of Greenland and Antarctica, the icebergs that break off and drift in the oceans, the glaciers on our high mountain ranges, our winter snow, the ice on lakes and the polar oceans, and the frozen ground in much of the Arctic landscape called permafrost.

The cryosphere is shrinking. Snow cover is reducing, glaciers and ice sheets are melting and permafrost is thawing. We’ve known this for most of my 25-year career, but the report highlights that melting is accelerating, with potentially disastrous consequences for humanity and marine and high mountain ecosystems.

At the moment, we’re on track to lose more than half of all the permafrost by the end of the century. Thousands of roads and buildings sit on this frozen soil – and their foundations are slowly transitioning to mud. Permafrost also stores almost twice the amount of carbon as is present in the atmosphere. While increased plant growth may be able to offset some of the release of carbon from newly thawed soils, much will be released to the atmosphere, significantly accelerating the pace of global heating.

Sea ice is declining rapidly, and an ice-free Arctic ocean will become a regular summer occurrence as things stand. Indigenous peoples who live in the Arctic are already having to change how they hunt and travel, and some coastal communities are already planning for relocation. Populations of seals, walruses, polar bears, whales and other mammals and sea birds who depend on the ice may crash if sea ice is regularly absent. And as water in its bright-white solid form is much more effective at reflecting heat from the sun, its rapid loss is also accelerating global heating.

Glaciers are also melting. If emissions continue on their current trajectory, smaller glaciers will shrink by more than 80 per cent by the end of the century. This retreat will place increasing strain on the hundreds of millions of people globally who rely on glaciers for water, agriculture, and power. Dangerous landslides, avalanches, rockfalls and floods will become increasingly normal in mountain areas.


Rising oceans, rising problems

All this melting ice means that sea levels are rising. While seas rose globally by around 15cm during the 20th century, they’re now rising more than twice as fast –- and this rate is accelerating.

Thanks to research from myself and others, we now better understand how Antarctica and Greenland’s ice sheets interact with the oceans. As a result, the latest report has upgraded its long-term estimates for how much sea level is expected to rise. Uncertainties still remain, but we’re headed for a rise of between 60 and 110cm by 2100.

Of course, sea level isn’t static. Intense rainfall and cyclones – themselves exacerbated by climate breakdown – can cause water to surge metres above the normal level. The IPCC’s report is very clear: these extreme storm surges we used to expect once per century will now be expected every year by mid-century. In addition to rapidly curbing emissions, we must invest millions to protect at-risk coastal and low-lying areas from flooding and loss of life.

Ocean ecosystems

Up to now, the ocean has taken up more than 90 per cent of the excess heat in the global climate system. Warming to date has already reduced the mixing between water layers and, as a consequence, has reduced the supply of oxygen and nutrients for marine life. By 2100 the ocean will take up five to seven times more heat than it has done in the past 50 years if we don’t change our emissions trajectory. Marine heatwaves are also projected to be more intense, last longer and occur 50 times more often. To top it off, the ocean is becoming more acidic as it continues to absorb a proportion of the carbon dioxide we emit.

Collectively, these pressures place marine life across the globe under unprecedented threat. Some species may move to new waters, but others less able to adapt will decline or even die out. This could cause major problems for communities that depend on local seafood. As it stands, coral reefs – beautiful ecosystems that support thousands of species – will be nearly totally wiped out by the end of the century.

Between the lines

While the document makes some striking statements, it is actually relatively conservative with its conclusions – perhaps because it had to be approved by the 195 nations that ratify the IPCC’s reports. Right now, I would expect that sea level rise and ice melt will occur faster than the report predicts. Ten years ago, I might have said the opposite. But the latest science is painting an increasingly grave picture for the future of our oceans and cryosphere – particularly if we carry on with “business as usual”.

The difference between 1.5°C and 2°C of heating is especially important for the icy poles, which warm much faster than the global average. At 1.5°C of warming, the probability of an ice-free September in the Arctic ocean is one in 100. But at 2°C, we’d expect to see this happening about one-third of the time. Rising sea levels, ocean warming and acidification, melting glaciers, and permafrost also will also happen faster – and with it, the risks to humanity and the living planet increase. It’s up to us and the leaders we choose to stem the rising tide of climate and ecological breakdown.

Mark Brandon, Professor of Polar Oceanography, The Open University.

This article is republished from The Conversation under a Creative Commons license. Read the original article.