Populations are shifting from rural areas to growing cities, creating megacities in the process. Because so many people arrive in cities before more houses or infrastructure are built to absorb them – with the exception of China, where migration is more subject to central control – a large percentage of the initial growth in megacities is likely to be in slums. Without urgently improving city infrastructure, there is a risk that the poor quality of life in megacities could spiral downwards into social collapse. We currently do not have proven infrastructure solutions or suitable models – can we rise to the challenge?

We are seeing mass migration to cities everywhere in Asia and Africa. A couple of billion people have moved from rural areas to cities over the last 50 years, and another couple of billion will do so by 2050. 

Ultimately, this will result in a slowdown in population growth as people have fewer children when they move from rural areas to city centres. For example, Brazil was one of the first emerging economies to experience mass migration in modern times – São Paulo’s population went from 2 to 20 million between 1950 and 2000 – and its fertility rate plummeted from an average of 6 births per woman in 1970 to 1.8 in 2010. However, Brazil as a whole will not start to experience population deflation until around 2030, about the same time as China, Indonesia and Iran; it will be the second half of the century before it is happening everywhere. We still have several decades of megacity growth to navigate before population pressure eases.

The fast growth of megacities poses the challenge of supporting quality of life. Three aspects of the infrastructure challenge need to be addressed. First, except perhaps for New York and Tokyo, the developed world has never had to deal with megacities – and New York and Tokyo became megacities a century ago. The most visible proposals for solving the widespread infrastructural deficiencies in megacities typically draw on what worked in relatively small rich cities in Europe – Amsterdam, Stockholm, Barcelona – the dynamics of which are incomparable with those of Nairobi, Mumbai and Lagos. 

Second, when the original megacities of New York and Tokyo were built, there were relatively few existing buildings or democratic mechanisms of control and stakeholder consultation. While obviously welcome, these mechanisms have the downside of making the implementation of new infrastructure an extremely slow process. Governments from all parts of the ideological spectrum feel helpless.

Third, capital is scarce and increasingly large parts of public spending will likely need to go towards health and pension needs, leaving fewer resources available for investing in infrastructure.

Innovative solutions to the infrastructure challenge will have to be found in new places – and there are three reasons for optimism. First, for the first time in history, top-quality education is available free of charge to hungry students everywhere, potentially expanding by a couple of billion the number of talented people equipped with the skills to play the innovation game. The more minds applied to the problem – especially those with first-hand experience of it – the greater the chance of solutions. These are the next billion we need to listen to, collaborate with and support with mostly existing technology.

We need to match this increasing supply of innovation from new geographies to the need to develop new mechanisms for listening to megacity populations, by leveraging new effective technologies such as social networks and crowdsourcing. Early indicators of expectations can be found in the new middle classes and their growing protests all over the globe.

Second, the technology already exists to design and pilot radically new possible solutions – smart grids, electric self-driven cars, multitudes of sensors, hyper-loops and decentralized in-memory computing through the “Internet of Things”. Fast and bold deployment of these mostly existing technologies will provide the opportunity for megacities to “leapfrog” in infrastructure development. Everything – from cars to traffic infrastructure to water and waste management to security – can now have embedded sensors, as we move from 10 to 50 billion devices connected to the web in just a few years, creating a global mesh of information, data and instantaneous processing. 

Third, this is a time to lead by democratic example. The hardest part of the solution is to deploy new projects and new capabilities within a well-functioning governance structure, and deciding who designs, who implements and who pays. The technology is ready. We need success cases, small and large victories, everywhere to catalyse action. 

If solutions are not found, the result could be collapse. Declining quality of living in megacities – rising costs, unmanageable traffic, debilitating pollution, critical water problems, rampant crime – is already leading to visible mass protests and brain drain. We need to find solutions to avoid collapse and get us through the next two or three decades, after which reduced population growth will begin to reduce the pressure on infrastructure. 

Megacities need to flourish as design leaders of innovative solutions, where its population can increasingly live lives blessed with quality and meaning – before they become tired old places with little to offer. We need urgently to find ways to harness existing technology and new brainpower to create amazing showcases for improving the quality of life in the megacity of the 21st century. The power of the next billion.