Where are largest cities in the world? 2015 edition

The world's biggest cities from above. Image: Getty.

The number of people who live in a city, as we may have mentioned before, is surprisingly hard to work out. That's partly because populations shift and change, unnoticed by demographers.


Mostly, though, it's because you quickly run into the fact that different authorities define their cities in entirely incompatible ways, rendering any attempt to compare them a bit like comparing apples with trucks. What you really need is a single source that follows a single set of rules: the results may not be perfect, but at least they'll be consistent.

That’s where Demographia comes in. The St. Louis-based consultancy was founded by the urban planner Wendell Cox (who, unusually for someone in that line of work, likes to write articles for conservative publications about the benefits of private car ownership). It also has a website that is, with the best will in the world, not massively easy on the eye.

But every year Demographia publishes something rather good: the World Urban Areas Report, a sort of bumper book of city population stats. You can check out the 11th edition here.

Here’s how it defines a city:

An urban area ("built-up urban area," urbanized area or urban agglomeration) is a continuously built up land mass of urban development that is within a labor market (metropolitan area or metropolitan region). An urban area contains no rural land... [It] is best thought of as the “urban footprint” – the lighted area that can be observed from an airplane (or satellite) on a clear night.

This year's edition of the World Urban Areas Report covers more than a thousand of the largest cities in the world, from Tokyo (pop. 37,000,000), right down to tiddlers like 850th-ranked Leicester (Pop. 534,000): all 1,009 cities, in fact, with a population of half a million of more.

Here are the top 10. See if you can spot any pattern.

 

Seeing it yet? Need a clue?

Okay, here's the same chart again. This time, we’ve coloured the cities by continent.

 

Yep.

Asia's dominance continues as you move down the league tables, too. Here's the top 20:

 

The world's largest continent, in fact, is home to 33 of the world's 50 largest cities, and 50 of the top 100. After that we got bored and stopped counting.

This isn't quite as extreme a result as it may appear: Asia, after all, is home to just shy of 60 per cent of the world's population. So the way in which the 2.1bn people who live in cities of half a million souls or more are distributed around the globe is largely a function of where people actually live. Look:

Comparing those two graphs, you can see that the Americas and Australia are unusually urbanised, Africa unusually under-urbanised, and Europe and Asia are pretty close to what you'd expect.

There are two other striking things about these league tables.

China rules

The first is the dominance of China, which takes 12 places in the top 50, and 22 of the top 100.

Again, this shouldn't be surprising – it's the world's most populous country, home to nearly a fifth of humanity – but nonetheless, it's striking how many of these megacities you almost certainly haven't heard of.

Where power lies

The other striking thing here is how far down the league tables many of the world's most powerful cities fall. Here's where some of the places that commonly make the “world city” league tables fall:

 

Size, it seems, isn't everything.

The data

Here, for completism's sake, is a chart showing the figures for all the city population charts above. You can find the full data set on Demographia's website, here.

Rank City Population
1 Tokyo-Yokohama 37,843,000
2 Jakarta 30,539,000
3 Delhi 24,998,000
4 Maniilla 24,123,000
5 Seoul-Incheon 23,480,000
6 Shanghai 23,416,000
7 Karachi 22,123,000
8 Beijing 21,009,000
9 New York 20,630,000
10 Guangzhou-Foshan 20,597,000
11 Sao Paulo 20,365,000
12 Mexico City 20,063,000
13 Mumbai 17,712,000
14 Osaka-Kobe-Kyoto 17,444,000
15 Moscow 16,170,000
16 Dhaka 15,669,000
17 Cairo 15,600,000
18 Los Angeles 15,058,000
19 Bangkok 14,998,000
20 Kolkata 14,667,000
25 Shenzhen 12,084,000
28 Tianjin 10,920,000
29 Paris 10,858,000
31 Chengdu 10,376,000
32 London 10,236,000
37 Chicago 9,156,000
41 Dongguan 8,442,000
43 Wuhan 7,509,000
45 Hangzhou 7,275,000
46 Hong Kong 7,246,000
47 Chongqing 7,217,000
50 Quanzhou 6,710,000
57 Nanjing 6,155,000
58 Shenyang 6,078,000
59 Xi'an 5,977,000
62 Qingdao 5,816,000
68 Singapore 5,624,000
72 Suzhou 5,246,000
76 Zhengzhou 4,942,000
77 Washington DC 4,889,000
79 Harbin 4,815,000
89 Boston 4,478,000
90 Xiamen 4,420,000
94 Dalian 4,183,000
97 Berlin 4,069,000
99 Fuzhou 3,962,000
101 Dubai 3,933,000
299 Amsterdam 1,624,000
832 Geneva 599,000
 
 
 
 

Which nations control the materials required for renewables? Meet the new energy superpowers

Solar and wind power facilities in Bitterfeld, Germany. Image: Getty.

Imagine a world where every country has not only complied with the Paris climate agreement but has moved away from fossil fuels entirely. How would such a change affect global politics?

The 20th century was dominated by coal, oil and natural gas, but a shift to zero-emission energy generation and transport means a new set of elements will become key. Solar energy, for instance, still primarily uses silicon technology, for which the major raw material is the rock quartzite. Lithium represents the key limiting resource for most batteries – while rare earth metals, in particular “lanthanides” such as neodymium, are required for the magnets in wind turbine generators. Copper is the conductor of choice for wind power, being used in the generator windings, power cables, transformers and inverters.

In considering this future it is necessary to understand who wins and loses by a switch from carbon to silicon, copper, lithium, and rare earth metals.

The countries which dominate the production of fossil fuels will mostly be familiar:

The list of countries that would become the new “renewables superpowers” contains some familiar names, but also a few wild cards. The largest reserves of quartzite (for silicon production) are found in China, the US, and Russia – but also Brazil and Norway. The US and China are also major sources of copper, although their reserves are decreasing, which has pushed Chile, Peru, Congo and Indonesia to the fore.

Chile also has, by far, the largest reserves of lithium, ahead of China, Argentina and Australia. Factoring in lower-grade “resources” – which can’t yet be extracted – bumps Bolivia and the US onto the list. Finally, rare earth resources are greatest in China, Russia, Brazil – and Vietnam.

Of all the fossil fuel producing countries, it is the US, China, Russia and Canada that could most easily transition to green energy resources. In fact it is ironic that the US, perhaps the country most politically resistant to change, might be the least affected as far as raw materials are concerned. But it is important to note that a completely new set of countries will also find their natural resources are in high demand.

An OPEC for renewables?

The Organization of the Petroleum Exporting Countries (OPEC) is a group of 14 nations that together contain almost half the world’s oil production and most of its reserves. It is possible that a related group could be created for the major producers of renewable energy raw materials, shifting power away from the Middle East and towards central Africa and, especially, South America.

This is unlikely to happen peacefully. Control of oilfields was a driver behind many 20th-century conflicts and, going back further, European colonisation was driven by a desire for new sources of food, raw materials, minerals and – later – oil. The switch to renewable energy may cause something similar. As a new group of elements become valuable for turbines, solar panels or batteries, rich countries may ensure they have secure supplies through a new era of colonisation.

China has already started what may be termed “economic colonisation”, setting up major trade agreements to ensure raw material supply. In the past decade it has made a massive investment in African mining, while more recent agreements with countries such as Peru and Chile have spread Beijing’s economic influence in South America.

Or a new era of colonisation?

Given this background, two versions of the future can be envisaged. The first possibility is the evolution of a new OPEC-style organisation with the power to control vital resources including silicon, copper, lithium, and lanthanides. The second possibility involves 21st-century colonisation of developing countries, creating super-economies. In both futures there is the possibility that rival nations could cut off access to vital renewable energy resources, just as major oil and gas producers have done in the past.


On the positive side there is a significant difference between fossil fuels and the chemical elements needed for green energy. Oil and gas are consumable commodities. Once a natural gas power station is built, it must have a continuous supply of gas or it stops generating. Similarly, petrol-powered cars require a continued supply of crude oil to keep running.

In contrast, once a wind farm is built, electricity generation is only dependent on the wind (which won’t stop blowing any time soon) and there is no continuous need for neodymium for the magnets or copper for the generator windings. In other words solar, wind, and wave power require a one-off purchase in order to ensure long-term secure energy generation.

The shorter lifetime of cars and electronic devices means that there is an ongoing demand for lithium. Improved recycling processes would potentially overcome this continued need. Thus, once the infrastructure is in place access to coal, oil or gas can be denied, but you can’t shut off the sun or wind. It is on this basis that the US Department of Defense sees green energy as key to national security.

The ConversationA country that creates green energy infrastructure, before political and economic control shifts to a new group of “world powers”, will ensure it is less susceptible to future influence or to being held hostage by a lithium or copper giant. But late adopters will find their strategy comes at a high price. Finally, it will be important for countries with resources not to sell themselves cheaply to the first bidder in the hope of making quick money – because, as the major oil producers will find out over the next decades, nothing lasts forever.

Andrew Barron, Sêr Cymru Chair of Low Carbon Energy and Environment, Swansea University.

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