10 ways of visualising London's growth

London, as viewed from the International Space Station in February 2013. Image: NASA.

This month, so the number crunchers tell us, London hit a milestone: the city's population has finally exceeded the peak it previously hit in 1939. In other words, it's taken 75 years for the city to recover from the impact of the Second World War.

This, then, seems as good a time as any to look at how London's population has changed – and work out how to visualise how 8,615,000 people are crowding into this town these days.

Bouncing back

For much of the late 20th century, London's population was falling: between WW2, and the nadir set around 1981, the city lost over 2m people, nearly a quarter of its population.

You might be wonder whether this was a reflection of broader demographic trends, but no. In the time that London's population fell from 8.6m to just 6.6m, the population of the UK as a whole grew by nearly a fifth (from 47.8m to 56.3m, if you're counting). In 1939, the area that's now Greater London held approximately 18 per cent of the national population; by 1981, it was less than 12 per cent.

Image: CityMetric.

This wasn’t an accident: in fact, it was the result of deliberate policy choices, which involved clearing some high-density housing from inner London, and decanting its former occupants out to a ring of new towns around the capital. In the decades immediately following the war, London was very much not the place to be.

Over the last 30 years, however, the capital’s share of the national population has rebounded slightly (to 13 per cent, since you ask). What's more, if you take the long view, those four decades start to look like a blip. Here's the population of the area that's now Greater London, starting in 1801 and projected into the future:

Image: CityMetric.

Put like that and it looks suspiciously like the city has returned to its natural trend growth.

It doesn't look likely to stop, either. On current trends, London will hit 9m by the end of the decade, 10m by the mid 2030s and 11m by the middle of the century. In other words, over the next 30 years or so, London's population is going to grow by something like a quarter.

One might think it's time we started trying to find places for all those extra people to live – a task that'd be much easier if a whole fifth of the capital wasn't technically classified as green belt:

Image: Centre for Cities.

...but we've banged on about that quite enough for one month, so let’s talk about something else. Let’s ask whether the idea that London has only just returned to its previous peak of population might actually be a touch misleading.

Pushing out

The 8.6m figure that everyone's been touting was the 1939 population of what is now Greater London.

In 1939, though, there was no Greater London: there was the London County Council, yes, but that population figure we’ve been discussing also included most of Middlesex, large chunks of Surrey, Essex and Kent, and a sliver of Hertfordshire, too.

In other words, 8.6m was the population of metropolitan London – a definition of the city that included areas outside the boundaries but within its economic footprint. If we want to compare like with like, maybe we should forget about administrative boundaries, and instead compare that figure with the population of metropolitan London today.

This is fine idea in theory – but working out where London ends in practice is no easy business. One option is to take the continuously built up area: that includes most (but not quite all) of Greater London, as well as various outlying towns that are attached to it. Here's how the Office for National Statistics (ONS) defined it at the time of the 2011 census.

You can click this one to expand it. Image: Eopsid, via Wikimedia Commons.

And here's the same data, this time with administrative boundaries included.

Image: Rob984, via Wikimedia Common, with labels added by CityMetric.

In 2011, this area had a population of 9.8m, which is substantially more than London proper.

But you can question whether this is definition is particularly helpful. Towns like Hemel Hempstead and Harlow are dormitory suburbs, defined in large part by their relationship to London. But the same goes for other nearby towns, such as Brentwood or Slough, which aren’t included in the data. Should they really be classified differently, just because they're don't have the same concrete umbilical cord to the city?

The ONS (which is quite fickle as government statistical agencies go) doesn't always think so. A few years ago, it used 2001 census data to split Britain into 243 “Travel to Work Areas”: the idea was that the 75 per cent of the people who lived in any one TTWA work also work in the area, and vice versa.

Here's what the ONS came up with for London:

Image: MRSC, via Wikimedia Commons. 

That area, by 2005, had a population of around 9.3m. In other words, even 10 years ago, it was substantially bigger than the city proper is today; it's fair to assume it's grown since.

Others have come up with different interpretations of the same sort of data. Last year, regeneration expert and CityMetric contributor Barney Stringer produced this map to accompany a blogpost headlined, “Is London too small?” It basically refines the TTWA concept, using 2011 data:

Image: Barney Stringer.

Then there's the Centre for Cities version, which appears in the Cities Factbook 2015. That defines London like this:

Image: CityMetric, based on Centre for Cities data.

Possibly the broadest definition of the city, though, is the one used by the EU statistical agency Eurostat to define London's “larger urban zone”. That includes basically all the areas included in the Travel to Work Area; the entire continuous built up area; most of the counties of Surrey, Hertfordshire, Essex and Kent; and chunks of Berkshire and Buckinghamshire, too. Here's the result:

Greater Greater London. Image: CityMetric, based on Eurostat data.

This area, Eurostat reckons, has a population of just over 13m, making it the largest city in Europe. (Paris, in second place, doesn't quite make it to 12m.)

Which of these definitions is “right” is a moot point (in some ways, they all are). But what we can say is that, when you define London by its economic footprint, rather than its administrative boundaries, the city probably passed its previous peak of population some time ago.

Take the broadest definition, indeed, and you’ll find it includes many of the new towns to which the population of inner London was decanted after the war. Look at things like that, and it's entirely possible that the city's population never fell at all.

This is the first half of a two-part article. Next time: the rise of the suburbs. 


 

 
 
 
 

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