According to the United Nations (U.N.),1 66% of the world’s population, or about 6 billion people, will live in urban areas by 2050, compared with 2% at the beginning of the 19th century, 30% in 1950 and 54% in 2015. Current annual population growth is equal to 100 cities counting 1 million inhabitants each. Rural flight, which always coincides with industrialization, has reached extremely high levels in India, China and Nigeria, the three emerging urban giants.
By 2050, about 40 megacities will have more than 10 million inhabitants, compared with 28 cities in 2015. By 2030, Tokyo’s population should drop slightly from 38 million to 37 million people but the Japanese capital will remain in first place ahead of New Delhi, with 25 million inhabitants today, Shanghai, with 23 million, and Mexico City, Mumbai, São Paulo, Osaka and Beijing, all with about 20 million inhabitants.
The most striking phenomenon is the growth of cities with between 100,000 and 500,000 inhabitants, in particular in developing countries. Today, these cities account for 2 billion people, over half of the world’s urban population. In addition, in countries like India, it is difficult to differentiate between cities and networks of large villages.
The vast range in sizes of cities and their levels of development, in addition to different public policies and community values, means that there is no one type of city of the future. However, by looking at a variety of studies2, it is possible to identify a few trends.
A Local Approach
With the emergence of positive-energy buildings, eco-districts and “green” megacities, local structures at multiple levels are becoming more and more important. Their goal is to move toward the principles of sustainable developmentThis term was first defined in the Brundtland Report, published in 1987, as “development that meets the needs of the present without... , in particular by producing their own energy (using primarily renewable energyEnergy sources that are naturally replenished so quickly that they can be considered inexhaustible on a human time scale... sources) and consuming it onsite for heating homes, powering electrical equipment, providing transportation and supporting local industry. Local energy systems3 are becoming more difficult to manage, with increasingly involved citizens and elected officials. This contrasts with a more than century-old energy distribution system that often functions based on a top-down model, starting at concentrated production systems and feeding through centralized networks. However, growing autonomy does not mean full self-sufficiency, as central networks remain essential for bridging the gap between various zones (see Close-Up “A New Way of Managing Energy Communities”).
66 %: The percentage of the world’s population who will live in urban areas by 2050, representing around 6 billion people.
Higher Density, Green Spaces and Vertical Farming
For many years, single-family homes where the dream; however, many city planners are now advocating urban densification to prevent sprawl, which is detrimental to rural and natural areas, and to move homes and workplaces closer together. Over time, they also plan to reintroduce vegetation to brownfield sites and create “greenways” around buildings to increase urban areas’ ability to capture CO2See Carbon Dioxid and reduce urban heatIn the field of statistical thermodynamics today, heat refers to the transfer of the thermal agitation of the particles making up matter... islands. Vertical farming is even beginning to make an appearance in cities to feed new populations and avoid the energy cost of transporting produce (see Close-Up “Urban Agriculture”).
New Mobility Methods
Throughout history, urban population growth has always raised questions about how to manage travel-related congestion. We have moved beyond the notion of “urban transportation” to the concept of “mobility”, which includes new means of getting around, the need to connect these solutions to one another, known as intermodality, varied uses and community values including increasing free time and leisure activities.
Modes of transportation are increasing in number, with automated light rail trams, cable cars, autonomous vehicles on fixed routes, cargo bikes, which have made a comeback, bicycles, scooters and hoverboards. Usage patterns are ever more divers, with car sharing, carpooling, self-service car and bike rental and “on‑demand” transportation reserved on mobile applications.
“The Earth Is Not Flat; It Is Urban” is the title of a 2016 U.N. report on the world population.
Urban Big Data
Digital data are ubiquitous in today’s city management. To control energy use in buildings and eco-districts, better knowledge of both production flows and consumption phases is required. Data collected by sensors and geolocation systems allow for better road traffic management. The need for higher security in cities has multiplied the amount of video surveillance. Public services and administration are being digitized at every level. This big data requires new regulations, both to ensure effective management and to protect citizens’ individual liberties.
(1) See the U.N. report “The Earth Is Not Flat; It Is Urban”.
(2) See in particular: The Cité des Sciences et des Techniques conferences (in French only); French Alternative Energies and Atomic Energy Commission (CEA) studies (in French only); The Fabrique de la Cité think tank (VINCI); Clés de Demain (IBM) (in Frnech only); and Connexions (Veolia) (in French only).
(3) Called eco-districts or “local energy communities” in Europe, “smart communities” in Japan and “community choice aggregations” in the United States.