Dense Cities

As urban migration increases, efficient, densely populated cities, not distributed options, are the blueprints for more sustainable places to live.

By 2025, nearly 2.5 billion Asians will live in cities. This urban growth is being fuelled by new levels of mobility and the migration of diverse populations within and across nations – especially in China, India and Brazil. These rural-to-urban migrants are attracted to live in cities by a number of factors – more opportunities, better jobs, better education and better healthcare. Cities like Mumbai experience over forty people moving into the city every hour. However, while a better quality of life is the aspiration, often the reality is very different. Especially in Africa, but also in Asia, unemployed urban populations frequently congregate in squatter camps or slums. Indeed, as they grow, most cities experience an equal growth in slums. Having ‘two cities in one’ is common and the frequent attempts to shift the slums to the periphery increases the rich–poor gap and in many eyes makes cities less sustainable: low-wage populations in particular need to be near to their work so that they can spend more time earning and less time travelling. As was stated in Mumbai, ‘we need the slums’.

According to the UN, one-fifth of all urban housing comprises temporary structures and a third of the world’s urban population lives in slums. In sub-Saharan Africa, over 70% of people live in unplanned areas. ‘One billion people live in disease-spreading slums characterised by inadequate housing, unsafe drinking water and open sewer systems. This makes the builders of informal housing the largest housing developers in the world and it is they who are creating the cities of tomorrow.’

As Ricky Burdett highlighted, with the right decisions we can address the problems: ‘Take, for example, Ciuadad Neza in Mexico City where, as hundreds of thousand immigrants arrive each year, an open ended and networked community is succeeding in establishing a lively economy out of literally nothing.’ Similarly, ‘New Delhi holds 13 to 14 million people depending on the time of day. It used to have the highest pollution rates in the world but then overnight all the auto-rickshaws and the buses were made to change from diesel to natural gas. If you can use natural gas in New Delhi, then why can’t you use it everywhere? Tokyo is the largest city in the world. Its transport system, integrated by overhead and underground rail systems, means that the average commute is around one hour. Compare that to Los Angeles, where the average commute is about two hours and at least 80% of the population takes the car to work. In Tokyo, 80% of the population uses public transport. There is little doubt that, seen through the lens of efficiency, more densely populated, compact cities such as Hong Kong and Manhattan are inherently more sustainable places to live than the likes of Houston and Mexico City.’

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However, some see that while they attract a lot of attention for their efficiency, ‘high-rise cities like Manhattan and Hong Kong are not the best models for every location. Low-rise, medium-density cities with between three and seven stories can also provide effective and efficient compact urban environments – for example, look at Paris which is the third most densely packed city in the world but has only one high-rise building.’ Others disagree and point out that, ‘Although Paris is a good example of a dense city without high-rise, it also has problems’ because ‘the centre of the city is frozen’ and all the post-war growth has created ghettoisation which has resulted in increasing imbalance in social mobility.

Ninety-five per cent of urban growth in the next twenty years will be in the developing world and there, especially, dense cities are seen as the way forward: ‘The future cities of Asia have to be dense rather than sprawls.’ But, in this, people recognise that there is no single global solution, no silver bullet, for city design: ‘Asia as a whole cannot have just one strategy. The solutions must be different for different countries.’ Likewise, ‘there is no singular solution to the urbanisation challenges faced by Asian cities. While the end goal – that of a sustainable city – is the same, the roadmap of how to get there has to be customised to the unique challenges of each city/region.’

While the global mega-city is one extreme interpretation of a dense urban environment, others see that groups of midi-cities are in many ways a better solution. ‘A network of interlinked cities’ with efficient transport systems operating between them can create a highly effective urban area without the challenge of scale in one place. Some commentators propose that the Netherlands, one of the most densely populated parts of Europe, is fast becoming a network of midi-cities. In an event held in Singapore, this view was endorsed again, as ‘new cities must follow a poly-centre model rather than having a single central business district. This will help cities cut down on travelling distances and transport demand.’ And by another: ‘There is no need to focus on building mega-cities. The more compact the city, the more sustainable it is. One possible solution is the creation of a mega-region which will consist of a number of small and mid-sized cities.’ This is supported by a view from Saudi Arabia suggesting that, while it is easy to get excited about the global cities, local cities may have a greater overall impact, especially when connected to the global cities by effective transport networks. Equally ‘due to the natural relationship between cities and their inhabitants, we should strive towards bringing services closer to the citizens and consequently create a density of services in future cities. Actions such as decentralizing schools or creating more local shops would decrease the need for people to drive, sometimes even long distances where people live outside of the city centre, and consequently reduce the congestion and pollution in cities.’

It is not all about urban expansion, however. Several experts pointed out that we must remember that in some parts of the world, cities are not getting larger: ‘Global urbanisation in theory does not mean bigger cities in practice. In Europe, for example, declining populations in some countries means many of our cities are becoming less dense.’ Similarly, ‘while it is easy to talk about new cities, we must remember existing cities and the need to enhance them for the future. Think of the need for high-quality regeneration which is evident in many European cities.’ And, from Singapore: ‘Asia’s experience of urbanisation is vastly removed from that of Europe. Europe’s current challenge is that of regeneration. In Asia it is that plus the creation of brand new cities that are economically and ecologically sustainable.’

Within the core idea of a dense city many people highlighted the need for ‘quality open spaces’ and better consideration of people: the comment that ‘cities should be for people not cars’ was widely endorsed. ‘A primary focus for future cities must be to provide more quality open spaces – spaces that all can enjoy. For example we should free up as much public space for children. Parks are often so popular that they are too densely packed. Why not pedestrianise 50% of our streets as this would help to promote social interaction?’ Green space per capita is one benchmark of quality of life and the WHO recommends at least 8 m2 per person. In London the average is 20 m2, in Shanghai it is 10 m2 while in the sprawl of Los Angeles it is less than 7 m2. Gary Lawrence of Arup saw that ‘much of what is generally discussed in relation to measuring urban environments addresses mobility, access, economic security, and so on – the cores of human urban systems. These are not, however, the cores of the human experience that were uncovered during the ‘choice to stay’ discussion. Peoples’ choices to stay are rooted in non-monetary aspiration, fear and nostalgia, all issues difficult to quantify, but no less important for that.’ As was highlighted in Singapore: ‘In the next ten years, people will become even more environmentally conscious. The tide swell that is taking place now will effect a ten-year change. This will reflect in greener, better, safer cities.’

Another big concern raised by some about major future cities is that many of them are continuing to be built on the coast where better trade and communication with other countries has been a traditional rationale. With highly probable rises in sea levels caused by climate change over the next century, there is an emerging issue that most of the coastal cities in the world are not designed to float, or deal with floods. Recent research from the Scientific Committee on Antarctic Research highlights that, ‘on current projections, the average sea level will rise by 1.4 m by the end of the century.’ This would not only mean that the likes of Calcutta, Mumbai and Dhaka will be under water, but also, without considerable flood prevention investment, so will London, New York, Tokyo and Shanghai. Or, to put it another way, around 10% of the global population will be displaced. As many of ‘the cities for the next decade have already been planned’, this is worrying for some.

When we plan for the future, Ricky Burdett sees that ‘Cities of the future have to be organic, flexible and versatile. As society and aspirations alter over time, the city has to adapt to change. Utopian cities have never worked. The people that created Rome, New York and London certainly didn’t think of them as fixed artefacts that wouldn’t change over time. We have to be clever enough as urban designers to design the city like a metabolism, like a body. When it gets older and weaker, you do corrective surgery. Cities need to be versatile; otherwise they atrophy and die. For example, many cities of the past fifty years have been designed around the needs of the car. But as oil costs soar, the city of the future will increasingly need to adapt to modes of transportation that are not petrol-dependent. This will have a significant impact on the shape of the city.’ Others agree that future cities clearly also have to be more sustainable: ideally, they will ‘produce more energy than they need, become net carbon absorbers, collect and process waste within city limits and collect and clean recycled water.’ Dense cities offer this potential and so are widely supported as the best solution in the years to come.



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