8 more ways of visualising London's growth: a question of density

London from the air. You wouldn't think it, but it's a bit empty down there. Image: Daniel Chapman/Stirling Ackroyd.

Last week we published a selection of graphics showing how London's population had grown, how it had changed relative to the country that contains it, and how, on some definitions, the city was threatening to break its bounds and swallow large chunks of the south east. Then we published a bunch of maps to track the rise of the suburbs.

What we didn't do, though, was consider how the 8.6m Londoners were distributed within the city itself. Look at that and you'll swiftly learn that, in one crucial way, the British capital is very, very weird.

To metroland!

London's population was initially crowded into what is now inner London*: that's no surprise, as that’s where the city began, and as recently 100 years ago, much of what is now classified as "outer London" was open countryside dotted with villages and small towns.

From the late 19th century onwards, though, the population of what is now outer London began to grow, and grow, and grow. It overtook the population of inner London some time in the 1940s; the latter has never seriously threatened its demographic dominance since.

We've written before about the post-war depopulation of London. Split the city into its inner and outer rings, though, and it soon becomes clear that this description is, well, a bit simplistic.

Source: Census data.

The population of inner London actually peaked a quarter of a century before 1939, hitting 5m around the time of World War One. But it then starts to slide – at first slowly, but then accelerating after about 1930. From peak to trough, in the early 1980s, it falls to more than half.

But that’s just inner London. The population of outer London actually keeps rising until the 1950s, before flattening out. It dips a little after that, but never by more than about 7 per cent. Outer London is relatively stable.

In other words, the post-war depopulation of London was actually the depopulation of the inner city. In the “Metroland” years of the 1920s and 1930s, people moved out to more spacious newly homes on the shiny new tube lines. Later, this became an act of deliberate government policy, to clear bomb-damaged slums and decant a fair chunk of Londoners to new towns in the commuter belt.

This map, from Quod's Barney Stringer, tracks this trend, in two different ways. The size of the boroughs represents their population in 1939. Their colour represents their change in population since.

Image: Barney Stringer/Quod.

At a glance you can see that, on the eve of WW2, the inner city was still relatively crowded, but has massively depopulated since. Most of the outer boroughs, by contrast, have grown in population; and the more suburban the borough, the more it's likely to have grown.

Today, while both parts of the city are growing once again, around 60 per cent of Londoners live in the city's outer boroughs...

Source: 2011 census data.

...and, while we hear much less about them than some of the inner ones, all six of London's largest boroughs by population are actually out in the suburbs:

Source: 2011 census data.

What makes London weird

Okay, we promised you that London was weird, and you've patiently read this far in the hope of finding out why. So, here it is.

These awesome graphics come from the clever people at the LSE Cities programme. They show the average population of each part of a city over a 24 hour period (including residents, workers, tourists, etc). The higher the peak, the more densely populated the city. You can click for a larger version.

Click to expand. Images: LSE Cities.

You can no doubt see the pattern already, but let's hammer it home. Here are some similar graphics, also from LSE Cities, but this time only including residential population. (We’ve manipulated them a little to make them display better on our site, but we’ve not amended the graphics themselves.)

  

 

Click to expand. Images: LSE Cities.

...and here's London.

Click to expand. Images: LSE Cities.

Look at all that empty sky.

Two things stand out from this.

1) Whatever way you count it, London is much, much less densely populated that most megacities. We sadly don't have a similar graphic for Paris, which one might think a better comparator for London than, say, Delhi; but suffice it to say that the average density in Paris proper (the equivalent of inner London) stands at 21,500 per km2, which is higher than the peak population density for London listed in the graphic above.

2) London's population is much more evenly distributed. Most cities have a centre that's full to bursting, but then trail out to less populated suburbs and a relatively empty hinterland. In London, though, the inner city is not that much more dense than the suburbs, or the ring of commuter towns that surround it.

Here's a clearer image:

Click to expand. Image: Skate Tier/Wikimedia Commons.

London, in other words, is a freak.

The good news here is that, when you look at it like this, the city has loads of room for all those extra people wanting to come here. We could fit nearly 2m more people into the inner city, without any part of it exceeding its previous peak population. Four boroughs are, in one sense, half empty:

Click to expand. Image: Neil Hudson/Savills.

Maybe everything's going to be alright.

For the purposes of this article we’re using the Office for National Statistics definition of inner London, which includes Haringey and Newham, but excludes Greenwich. This is the third part of a series about how London's population has changed over the last 75 years. You can find the previous parts here and here.


 

 
 
 
 

Here’s how we plant 2 billion more trees in the UK

A tree in Northallerton, North Yorkshire. Image: Getty.

The UK’s official climate advisor, the Committee on Climate Change (CCC), recently published a report outlining how to reduce the 12 per cent of greenhouse gas emissions that come from land use by two thirds by 2050. Alongside recommending cutting meat and dairy consumption by 20 per cent, the report calls for the annual creation of up to 50,000 hectares of broadleaf and conifer woodland for the next three decades. This would increase forest cover from 13 per cent to at least 17 per cent – a level not seen in Britain since before the Norman invasion.

Reforestation at that rate would mean creating roughly the area of the city of Leeds every year for the next three decades. At typical stocking densities of 1,500 stems per hectare, the ambition is to establish some 2.25 billion additional trees. Given that the UK, as with most of Europe, is in the grip of ash dieback, a disease likely to prove fatal for many millions of native ash trees, the scale of the challenge is massive.

On a crowded and intensively farmed island like Britain, unlocking a million and a half hectares of land will be no mean feat. But it’s not impossible – and is an unprecedented opportunity not only to tackle the climate crisis but also the biodiversity crisis that is every bit as detrimental to our wellbeing.

Trees and farms

One million and a half hectares is just 6 per cent of the mainland UK’s land area. To give some sense of perspective on this, 696,000 hectares of “temporary grassland” were registered in 2019. So if land supply is not the problem, what is? Often it’s cultural inertia. Farmers are firmly rooted to the land and perhaps understandably reluctant to stop producing food and instead become foresters. But the choice need not be so binary.

The intensification of agriculture has caused catastrophic declines in many species throughout the UK by reducing vast wooded areas and thousands of miles of hedgerows to small pockets of vegetation, isolating populations and making them more vulnerable to extinction.

Integrating trees with the farmed landscape delivers multiple benefits for farms and the environment. Reforestation doesn’t have to mean a return to the ecologically and culturally inappropriate single-species blocks of non-native conifers, which were planted en masse in the 1970s and 1980s. Incentivised under tax breaks to secure a domestic timber supply, many of the resulting plantations were located in places difficult or in some cases impossible to actually harvest.

Productive farmland needn’t be converted to woodland. Instead, that 4 per cent of land could be found by scattering trees more widely. After all, more trees on farmland is good for business. They prevent soil erosion and the run-off of pollutants, provide shade and shelter for livestock, a useful source of renewable fuel and year-round forage for pollinating insects.

The first tranche of tree planting could involve new hedgerows full of large trees, preferably with wide headlands of permanently untilled soils, providing further wildlife refuge.


Natural regeneration

Where appropriate, new woody habitats can be created simply by stopping how the land is currently used, such as by removing livestock. This process can be helped by scattering seeds in areas where seed sources are low. But patience is a virtue. If people can learn to tolerate less clipped and manicured landscapes, nature can run its own course.

A focus on deliberate tree planting also raises uncomfortable truths. Most trees are planted with an accompanying stake to keep them upright and a plastic shelter that protects the sapling from grazing damage. All too often, these shelters aren’t retrieved. Left to the elements, they break down into ever smaller pieces, and can be swept into rivers and eventually the ocean, where they threaten marine wildlife. Two billion tree shelters is a lot of plastic.

The main reason for using tree shelters at all is because the deer population in the UK is so high that in many places, it is all but impossible to establish new trees. This also has serious implications for existing woodland, which is prevented from naturally regenerating. In time, these trees will age and die, threatening the loss of the woodland itself. Climate change, pests and pathogens and the lack of a coordinated, centrally supported approach to deer management means the outlook for the UK’s existing treescape is uncertain at best.

An ecologically joined-up solution would be to reintroduce the natural predators of deer, such as lynx, wolves, and bears. Whether rewilding should get that far in the UK is still the subject of debate. Before that, perhaps the focus should be on providing the necessary habitat, rich in native trees.

A positive response would be to implement the balanced recommendations, made almost a decade ago in a government review, of creating more new habitat, improving what’s already there, and finding ways to link it together. Bigger, better, and more connected habitats.

But the UK is losing trees at increasing rates and not just through diseases. The recent removal of Victorian-era street trees in Sheffield and many other towns and cities is another issue to contend with. As the climate warms, increasing urban temperatures will mean cities need shade from street trees more than ever.

Trees aren’t the environmental panacea that the politicians might have people believe – even if they do make for great photo opportunities – but we do need more of them. Efforts to expand tree cover are underway across the world and the UK will benefit from contributing its share. Hitting the right balance – some commercial forestry, lots of new native woodland and millions of scattered trees – will be key to maximising the benefits they bring.

Nick Atkinson, Senior Lecturer in Ecology & Conservation, Nottingham Trent University.

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