Healthy Megacities: The Solution Is Intuitively Obvious, But Is It Achievable?

In November of this year, global health leaders gathered at the World Health City Forum in Incheon, South Korea to discuss the future of the world’s megacities during a time of rapid and complex transformation. In 1800, only 3% of people lived in cities, with most living in villages, farmland, and remote landscapes. Today, our planet is urban, with more than half of the world’s population, 4.4 billion people, living in cities. This percentage varies across countries based on levels of development, with more than 80% of inhabitants in high-income countries living in urban areas compared to a majority in lower-income countries still living in rural areas, but this is rapidly changing. By 2050, 70% of the global population will live in cities, with rising incomes and shifts away from agricultural employment. New York and Tokyo became the world’s first “megacities” in the 1950s, and by 2030, there will be an estimated 43 of them spanning every region of the world.

Cities offer inhabitants opportunities, from employment and wealth creation to education and innovation. But many cities also pose grave threats to the population’s health. Health should be every city’s greatest asset. Designing cities with health at the center can suppress the growing tide of non-communicable diseases, build resilience against contagious threats like COVID-19, and reduce toxic emissions and mitigate the effects of climate change — an existential threat exacerbated by global development and urbanization.

A health-centered urban approach aligns with countries’ commitments toward the UN Sustainable Development Goals, and the human right to a clean, healthy, and sustainable environment. We have an obligation to take care of each other and of our planet — and the way to do this is deceptively simple, but faces enormous structural and political headwinds. We begin by describing the conditions for urban populations to be healthier, and then describe the means and obstacles to achieving those conditions.

Assuring the Conditions for Health, Safety, and Wellbeing

The ideal megacity is an epicenter for good health, safety, and wellbeing. A megacity that promotes good health starts with affordable and safe dwellings situated in neighborhoods designed to create the conditions in which everyone can be healthy and safe.

Let’s imagine a typical resident of a health-promoting metropolis. When she awakens and turns on the tap, the water is pure, potable, and free from lead or other harmful contaminants. When she sits down for breakfast, there is nutritious and safe food. When she leaves home for work or school, she breathes clean, unpolluted air, and is not attacked by malarial or dengue infected mosquitoes, exposed to rats or other vermin, or surrounded by unsanitary conditions. She travels to work or school, by walking or via mass transit, but if she uses her own vehicle, the roads are safe, and the vehicle is designed for safety. She lives in a tree-lined pedestrian- and cyclist-friendly neighborhood, with nearby parks and playgrounds. Grocery stores and fresh food markets, schools, and health centers are all easily accessible. Workplaces and other buildings have good indoor air quality, and reduce the risk of occupational and other injuries.

This is the classic public health approach: hygiene and sanitation, vector control, injury prevention, nutrition and physical activity, and surveillance against infectious and other diseases. The public health approach also takes us in the direction of greater equity. Anyone, no matter their income or social status, would have access to these shared urban benefits. In other words, health, safety, and fair treatment are built into the environment.

Why Cities Are Designed So Badly

One of us (LG) has done this public health thought experiment in cities across the globe — from New York to Native American reservations, London to Oslo, Tokyo to Beijing, Rio to Buenos Aires, and Johannesburg to Kampala. Everyone, in every region of the globe, yearns for a city designed around community health and well-being. And, yet, virtually all cities are designed in the exact opposite way. Why?

Most of the world’s 4.4 billion urban dwellers live in cities with poor housing affected by mold, lead, asbestos, and overcrowding; with air polluted by motor vehicles, household appliances, and industrial facilities; with poor sanitation, sewage, and water systems that allow disease vectors to proliferate; and with a paucity of safe spaces for walking and cycling, or green spaces to recreate. Over a billion people live in urban slums, a number projected to double over the next 30 years. Visit many cities, especially but not exclusively in developing countries, and life is extraordinarily hazardous. The air chokes the lungs and triggers respiratory diseases, the roads are chaotic and dangerous, food and water are unsafe, mosquitoes and other vectors are ever-present sources of disease, and there is precious little opportunity for recreation in green spaces, playgrounds, and sports fields. 

Most of the leading causes of death globally are linked to poor urban planning, design, and development. Air pollution is a major factor in the four leading causes of death: heart disease, stroke, pulmonary disease, and respiratory infections. Diarrheal diseases, the eighth leading cause, is tied to poor sanitation, waste management, and housing conditions. Diabetes, the ninth leading cause, is linked to unhealthy weight gain and physical inactivity, common in car-dependent cities that lack easy access to fresh food markets and grocery stores. Road crashes (they are not “accidents”) remain a leading cause of injury, disability, and death in low- and middle-income countries, with even higher risks of if safe, multiuse roadways are absent. Urbanization is also tied to soaring rates of depression, anxiety, and other mental disorders, exacerbated by noise, lack of green spaces, and crowding, as well as poverty, poor working conditions, and other stressors.

Aside from traffic crashes, which cause 1.3 million deaths each year, motor vehicles have enormous impacts on human and environmental health in urban areas. Cars have been celebrated for the possibilities that they bring to mobility and trade, yet they come with enormous, in our view, unacceptable costs. Cities produce 75% of the world’s carbon dioxide emissions, with transportation constituting a significant piece. Designing cities around car dependency has yielded dangerous levels of environmental pollution, and has increased cities’ vulnerability to climate change — particularly coastal cities affected by rising sea levels. Cities dedicate as much as 70% of public space to motor vehicles —roads, parking, strip malls. Along with urban sprawl, this use of space damages natural habitats, landscapes, and biodiversity. With less than half of urban residents having access to convenient public transportation, car-dependent cities deepen inequities surrounding the social determinants of health, such as employment, education, access to health services, and food security. 

And, while most of us would prefer a city designed around community well-being, we use every political influence to keep cities just the way they are. We fight for our car, which is associated with freedom. We demand that municipal governments build more roads to reduce road congestion, which incentivizes us to buy more cars, creating a vicious loop. We push for budgets to fix potholes and expand parking, in so doing reducing space for recreation, business, and affordable housing. The way most people see it is that the car is their ticket to freedom, to be celebrated. It is small wonder that cities are designed and maintained just the way they are. In contrast, we see the car as the enemy.

Designing Healthy and Safe Megacities

What would it take to transform our cities to promote good health and well-being for all? Innovative technologies are often posed as the solutions, such as intelligent traffic management systems, digital health tools, and data-driven energy use — many fueled by emerging artificial intelligence technologies. Yet new technologies are not panaceas, as many claim. Solutions must be grounded in the basic idea of creating environments with all the qualities and resources that people need to be healthy. Comprehensive law and policy changes can redesign our cities from the ground up.

Take transportation. Several cities are taking steps to get cars off the road, such as by removing hundreds of city parking spaces (Oslo), designating many streets as pedestrian-only or pedestrian-priority (Buenos Aires and London), and banning older, polluting vehicles from the roads (Madrid). Aside from encouraging active transport like walking and cycling, many cities are investing in extensive and sustainable mass transportation systems, such as electric buses to replace older, polluting ones (Dubai), and clean, efficient rail systems that support the vast majority of the working population (Tokyo).

Under the concept of the 15-minute city, all daily necessities and services, such as work, education, health care, nutritious foods and medicines, entertainment, and recreation, are within a 15-minute walk, bike ride, or public transit ride from any point in the city. Policies such as subsidies for essential services, like healthy food outlets, to locate in urban centers and along public transit routes can help make this vision a reality. In early 2023, England released a plan to put every household within a 15-minute walk of a green space, including by restoring natural habitats and reserves. As mayor of New York, Michael Bloomberg prioritized city residents living within a 10-minute walk of a park and planted a million trees. Trees, green roofs, and vegetation reduce urban heat islands by shading buildings, deflecting sun radiation, and releasing moisture into the atmosphere — on average lowering temperatures by 2.9°F. Creating and reclaiming more green spaces adds aesthetic appeal, promotes physical and mental well-being, and provides urban resilience to climate change.

If It’s All So Obvious, Why Don’t We Do It?

We have the solutions for redesigning cities to improve population-level health for over half the world’s population, and to combat climate change. Yet progress is met with sometimes fierce resistance. Mis- and dis-information are major problems. The concept of the 15-minute city was met with conspiracy theories that it was a government attempt to impose “climate lockdowns” and keep communities on a tight leash, or that it would further segregate cities. Congestion taxes designed to deter vehicles from entering already crowded urban spaces are widely opposed.

Beyond misinformation, people resist what they see as major changes to their lives, such as trading cars for public transportation, or even more mundane changes, such as switching from gas to electric cars or stoves. Politicians are often reluctant to take on sweeping and potentially unpopular projects that would overhaul urban design, instead focusing on short-term popular “fixes” that they can achieve over a short election cycle, such as filling potholes or building new bridges and roads. And, of course, cost is always a major factor, especially when there are discrete priorities that seem more urgent, such as improving schools, reducing crime, and supporting businesses.

Inequalities may mean that the people who would most benefit from healthy cities — because they face the most pollution, the least access to public transportation, and the fewest green spaces, for example — also have the least political power to press for change. Meanwhile, poorer residents may worry that upgrades in urban neighborhoods will make them more attractive, pushing up housing costs.

Yet, with the vast growth of urbanization, and serious threats like non-communicable diseases, infectious diseases, and climate change shortening lives and upending livelihoods, we cannot afford to push the problem to the next generation to solve. Creating healthy cities and megacities will require broad public agreement on the basic premise of creating the urban conditions that are truly needed for all people to be healthier and happier. Though it is far from the current reality, we have the knowledge and the tools to get there. But will we muster the political will to achieve it?

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