And it’s little surprise. Four years ago, the world reached a tipping point; humans became an urban species, with more than half of us living in towns and cities. According to the United Nations, Asia’s urban population is set to soar from 1.9 billion in 2011 to 3.3 billion by 2050, while Africa and Asia combined will account for 86 per cent of the increase in the world’s urban population. It’s a shift, not only in terms of population but also in terms of potential, that has sent ripples of anxiety throughout the corridors of power.

“Because of the ambiguity of the situation and the speed of development, onlookers like the United Nations and World Bank are seriously concerned that some cities are grossing out – they’ve got too nebulous, too large – and it’s causing a kind of urban existential panic,” says Webster.

“It’s happened several times over the last 40 years or so, when cities first topped populations of a million; when Istanbul and Cairo – right on the borders of Europe – reached 10 million; now China is setting the benchmark and it’s not so much the 10 million that’s raising questions but where it’s going beyond that.”

Now analysts in industry and academia are racing to make sense of how megaregions shake down in practice: who are the winners and losers in these giant agglomerations? And what does a mega-future really look like?

For Marcos Chan, head of research for Hong Kong, Macau and Taiwan at real-estate multinational CBRE, it’s a critical time.

“There’s a lot of discussion about this right now, especially in the light of the strategic development of Qianhai, to the northwest of Hong Kong.

What we’re probably seeing is Hong Kong, Shenzhen, Guangzhou, Zhuhai and even Macau all merging into one enormous metropolitan area but, although Qianhai has the potential to develop into a huge financial centre, I still think Hong Kong will stay pre-eminent and maintain its international identity while Qianhai plays a more important and strategic role in the development of the Pearl River Delta.”

MEGACITIES OF ASIA PART I: The rise and rise of the Asian megacity

MEGACITIES OF ASIA PART II: Perils of the concrete jungle

However, the new urban order doesn’t only matter for business. Megaregions bring a raft of challenges, not least what to call yourself as a resident in one of the component cities. Will you be, for example, a Hongkonger, a Shenzhener or perhaps a Shenkonger?

Chan laughs at the prospect. “I was born and brought up in Hong Kong so I’m definitely a Hongkie, not a Shenkonger, and I always will be.”

It seems that as regions get larger, instead of local differences becoming more homogenised, distinctive identities are retained. Or put another way, small is still beautiful – it’s just that the “small” is being subsumed by the “mega”.

“I’ve never met anyone who considers that they live in the Pearl River Delta,” says Webster. “Only planners ever use the agglomerate term and I think that’s because, on the Chinese side, the strongest level of governance is at the local level, so people define themselves this way; meanwhile, Hongkongers will proudly define themselves in opposition to the mainland.”

But what’s perhaps more interesting are the geopolitical implications of the new megacities and megaregions in terms of their own sense of identity.

What happens when they get so big and economically powerful that they can challenge the hegemony of the nation state?

“There is evidence to say that the city state is on the rise, re-emerging in function if not in form,” says Webster. “London, Beijing, Shanghai – they all have national-scale earning power, now, and it’s probably correct to say that the megaclusters in the PRD and Yangtze have already evolved their own kind of political as well as economic identity among their cities to vie with the central government.

“I think there are two things going on, though: firstly, you’re getting economic linkages between the cities which could well jeopardise the power of a nation state by linking laterally and exercising bottom-up regional geopolitical power. You can already see this to some extent with Tokyo, Frankfurt, New York and London – they’re leading their nations in terms of policy as they’re the core financial centres.

“Then you have the European situation whereby some cities feel closer to Brussels than their own national governments and, again, this can jeopardise the relationship between the city and the nation state. So, will the ancient Greek-style city-state re-emerge? I think yes, to a degree. Cities are becoming more and more powerful. Singapore is the classic example – it became a city state by ceding from the federated states of Malaysia; and you’ve also got Barcelona, which feels culturally different from the dominant ‘Castilian’ Spain and is in a surprisingly plausible bid to cede. Then you’ve definitely got Africa, where significant urban centres are trapped within an anachronistic geopolitical boundary system: just look at the colonially drawn territorial map of Africa to see how unnatural it is. Here you’ll get changes for sure that could well end up with some powerful city states: just look at the reshuffling going on between North and South Sudan and imagine that happening in Nigeria.”

American political scientist George Friedman has predicted, in his book The Next 100 Years, that, perhaps within a decade, the eastern seaboard of China will begin to break away from the poorer rump of the country and ally itself with Japan and Japanese money. However, when it comes to Asia, Webster is more sanguine.

“For cities or regions here to want to cede, you would need a sense of ethnic and cultural division, probably combined with relatively recently constructed geopolitical boundaries that coincide with differences in prosperity. I think Asia’s too politically stable and homogeneous in these respects for that to happen.”

But urbanisation has made fools of analysts before.

“Back in the 1960s and 70s,” says Webster, “there was a belief that oversized cities would burn themselves out. Academics constructed elegant theories that the rapidly growing proto megacities would reach an optimum size, some kind of equilibrium, and then stop getting bigger. But they didn’t! They kept on growing and they are still growing and changing and creating new forms.”

However, not all experts are so buoyant. Stephen Davies has spent the past decade studying the global maritime industry from his base in Hong Kong and he is more cautious about the region’s mega-future.

“It’s down to basic economics,” he says. “You can’t make stuff without stuff. The stuff we make stuff from in Asia, like iron ore and petroleum, is heavy and bulky to transport. The stuff it makes – mass consumer goods – is high volume. Modern shipping technology – massive bulk carriers, supertankers, box ships – means carriage at extremely low costs per tonnemile.

It’s this revolution that’s turned Asia into the world’s factory. This will continue as long as the costs of transportation stay low, and we stay the cheapest place to make stuff.

“But there are two blots on the horizon: firstly, as the West battles with recession, huge debts and a rising welfare bill, it’s cutting back on the mad consumerism of the 20th century and spending less, so the market there is shrinking. Second, we’re reaching a stage whereby developments in IT are significantly impacting on the production process.

Ultimately, artificial intelligence will get rid of much of the work done now by humans. First to go will be any routinised work for which an algorithm can be written. In other words, the cheap, production-line labour that has driven industrial development, wealth – and urbanisation – in Asia. This has really interesting consequences for Asian megaports, which are predicated on how trade has been done over the past 50 years.

“Another concern is that the whole of Asia’s economy is predicated on savings at home and consumption overseas, so if the West stops spending over here, the whole machine fails: we just won’t be able to change the indigenous savings culture to a spending one in time to service our megacities and megaports. And while we do have the super-rich who, in theory, could help spend us out of disaster, they tend to buy top-end, low-volume luxury goods – not the mass-volume goods China is churning out – and we don’t yet have a middle class big enough to become a replacement market.

“On that basis, I just don’t see how Asia can continue to expand at its current rate.”

Says Davies, “I think the real question is, is the world model of trade sustainable into the future? And I think an intelligent jury is out. It will probably keep on growing but I suspect we’ll see lots of quirks in the trend.

If you take the long view, the global growth of GDP over the last 50 years has been anomalously high, at 4 to 5 per cent. It’s much more normal sitting around 1 to 2 per cent, but that drop will hit Asia’s industrial megaregions and megaports hard.”

In the meantime, though, Asia’s new urban structures are growing in confidence – and ambition. In a bid to solve the social, economic and logistical problems of the old industrial cities, the new, “wired” cities of the future are being marketed as “smart”. To look at the promotional videos that accompany them, this is Sim City writ large, and – allegedly, at least – coming to a megaregion near you! Last month’s election victory for Narendra Modi’s Bharatiya Janata Party was a clear vote for a pro-business, pro-city model of development, assuring India’s future as a global hub of capital. And central to that future are numerous smart cities – the new, ultra modern, hi-tech urban regions rising out of the dust and promising the very best in 21st-century living.

Without doubt, Modi has big plans for India, but not everyone is convinced.

“The new prime minister has promised huge investment in this new model of urbanisation,” says Ayona Datta, a senior lecturer in citizenship and belonging at Britain’s University of Leeds who specialises in the politics of urbanisation.

“He’s promised 100 new smart cities and vast new ‘urban corridor’ projects linking Indian megacities across the country. The current corridor under development between Delhi and Mumbai includes an influence zone of 150km on either side for motorways, freight and land development. There are now 24 smart cities being planned to accommodate the new figures for urbanisation that are emanating from the World Bank. But what no one is talking about is the huge land acquisition that is behind this form of urbanisation, where already marginalised rural populations are dispossessed and have no option but to head to the city to find employment.”

The claim is that the new smart cities will avoid many of the social and environmental problems that have so far blighted Asian urbanisation. But just how “smart” are they, or is it all just clever marketing of the emperor’s new clothes?

“There is no such thing as a smart city, or an ‘eco’ city, despite what all the propaganda tells you,” says Webster, laughing. “They’re nice but nonsense – just vision statements, that’s all. For the moment, it’s all just rhetoric, but I do think that in 20 years’ time there could be some in China in the sense that you’ll be able to say, ‘This city will have a lower carbon footprint.’ But you’re unlikely to get it elsewhere in Asia because nowhere else has the same degree of control, certainly not India.”

Datta has studied many of the “smart” Indian plans and is similarly unconvinced: “In Gujarat, they’re using Japanese know-how to follow a Chinese model of mega-urbanisation and using Western companies like IBM and Siemens to design the smart technologies that they say will underpin these cities. Then, of course, what is happening is that India is being opened up as a new ‘market’ for smart cities for these corporate IT companies, seen in the establishment of the first regional chapter of the US-based Smart Cities Council in India. It is trickle-down theory but this just hasn’t happened in reality. Things like citizenship rights, social justice, gender justice, religious expression – they just get lip service in these urban plans.”

But for politicians and businesspeople, the numbers are hard to ignore.

Indian growth is currently about 4.5 per cent; the state wants 8 per cent, and it’s looking to Modi to deliver the same impressive growth he brought as chief minister of Gujarat, which ran at an average of 10 per cent.

Again, Datta is sceptical. “People aren’t seeing beneath the figures to the higher social costs that come with urbanisation, in terms of things like the increases in pollution, in childhood mortality, in maternal mortality, in family relationships. So although economic growth has increased, well-being has decreased for those at the lower socioeconomic levels in society.”

Despite this, Modi’s drive towards mega-urbanisation has won him huge popular support among Indian youth, who see a better life for themselves in a global economy. In India as in China, for many in the middle classes, the advantages of global investment and the entry of foreign multinational companies outweigh all the disadvantages. The poor, on the other hand, migrate from rural to urban areas in search of employment but they cannot fit into these new visions of cities and find themselves living in slums in the megacities.

One surprising group to benefit, at least on the surface, are the females living in the vast slums that shroud the megacities of Mumbai and Delhi.

Whereas boys tend to be sent out to work before they complete their state education at the age of 11 or 12, girls are regarded as less economically valuable and therefore complete their education, almost by default. This has resulted in much higher levels of literacy and employability among females living in the slums than their male – or rural – counterparts.

However, as Datta explains, this too comes at a cost.

“As manufacturing moves out of the city, more men are becoming unemployed; meanwhile, women are finding employment more readily.

They’re out working when their husbands are at home, and this causes its own tensions, including male alcohol abuse and domestic violence. So women are experiencing new forms of marginalisation as they become the breadwinners: there are more restrictions on their movement and if they venture too far from home, they are often seen as immoral.

“‘Eve-teasing’ – catcalls, verbal and physical abuse, groping – is part of everyday life for women in India’s cities. But in the interviews I’ve been doing, the woman won’t usually tell her husband what’s going on as he’ll think she was complicit. It really is the classic double bind; she goes out to work and gets all the hassle.”

Despite the expensive promotional videos and glossy travel features, it seems the brave new world of the Asian megacities is as messy and complex as you might expect from millions of people living cheek by jowl, carving out new lives amid the biggest social experiment in the history of our planet.

Perhaps what’s most remarkable is just how much the poorest in society are able to endure. Despite the gruelling lives of many of her interviewees, Datta says they are still finding ways to cope and survive.

“What I’ve seen in Delhi and Mumbai is that it’s in families – at an individual level – where the costs are being felt the most, and yet most of my stories are stories of strength and hope. But my lasting impression is that it’s not so much the economy as societal values that need fixing. You have a traditional society that’s been transformed overnight so it is struggling to fulfil its new social function. You need social transformation with urbanisation – you can’t just rely on economic gains to address societal problems.”

Webster agrees that people will sacrifice almost everything for a life in one of the new megacities.

“There’s a real sense that while we know that living in these cities can easily kill you, it’s not going to drive people out. They’re investing in aspiration. So, people just swallow the higher rents and all the social and medical problems. As long as there’s a net cash inflow, they feel a greater economic well-being in the city.

“Individuals are relentless survivors and will put up with a lot; too much, perhaps. The real question about high-density megacity living is whether this is all socially sustainable – and if not, what adjustments are needed.

“Individuals don’t ask such questions. Governments should.”

MEGACITIES OF ASIA PART I: The rise and rise of the Asian megacity

MEGACITIES OF ASIA PART II: Perils of the concrete jungle