Are urban populations growing exponentially all over the world, as commonly assumed?

“This is simply no longer true,” says Shlomo (Solly) Angel, a professor of city planning at the NYU Marron Institute.

The fact is that while cities may be growing, they’re growing unequally.

The U.N. projects that, between 2020 and 2050, 2.3 billion people will be added to cities, and for every person added in the Global North, 18 persons will be added to cities in the Global South.

In the Global North, urban population growth is “largely at a standstill,” Angel explains, while what we call urbanization—“the movement of people from being closer to the land to being close to one another,” is now, by and large, limited to the Global South, and expected to largely taper off by the end of this century.

Until then, the acceleration of migration to cities in less-developed regions in sub-Saharan Africa, the Indian subcontinent, East Asia, and other reaches of the Global South presents a humanitarian challenge, Angel explains. 

Shlomo Angel on New York City street

Shlomo (Solly) Angel. Photo by Tracey Friedman.

“Unless the economically developed countries in the Global North open their borders to asylum seekers, economic migrants, and climate migrants as well on a massive scale—an increasingly unlikely scenario, given the rise of nationalist, xenophobic, and racist anti-immigration parties in so many countries in the Global North—the burden of urbanization will fall largely to municipal officials in cities large and small in the Global South,” he says. “And those cities have few resources, be they professional, institutional or financial, to accommodate urban growth.”

With that reality in mind, Angel spent the past year developing Accommodating Urban Growth, a new eight-hour online course on to help municipal officials in the Global South prepare for dramatic changes to their cities.

Launched in October, Accommodating Urban Growth offers practical tools for taking a proactive, orderly approach to managing the influx of new urban populations, with the goal of building cities that are productive, inclusive, environmentally sustainable, and better able to accommodate climate change in the decades to come.

Crucially, the course provides city planners with realistic pathways for settlement into the urban periphery by setting the stage for “green” expansion. That means connecting the periphery to the urban job market with public transport, protecting environmental assets from encroachment, and relaxing regulations to allow emerging neighborhoods to be built at higher densities. While densification is one way of mitigating climate change, Angel explains, expansion is often necessary too.

 “Our research has confirmed that in the past two decades, only one-quarter of the population added to cities was accommodated by densifying their existing footprints, while three-quarters was accommodated in newly built expansion areas,” he says.

Prepared with a grant from C40 Cities (a global network of mayors), the online course is made up of some 120 short videos and is accessible at no cost through Zoom. Participants can either view the videos or read illustrated scripts, currently in six languages: English, Spanish, French, Portuguese, Mandarin, and Bahasa Indonesia.

“The traditional goal of effective urban planning since time immemorial was to prepare cities to accommodate the growth in their population, commerce, and civic life by laying out streets and public open spaces at the anticipated scale on the urban periphery before it was occupied,” Angel explains. “One of the principal objectives of this course is to revive this tradition, to create the local capacity in the cities in the Global South to accommodate their expected urban growth in an effective manner, at scale, with climate change in mind, and with the goal of developing its cities in an inclusive, sustainable, and resilient manner.”

The course is making its debut when urban plan-making has become a thriving international industry, with consulting firms offering municipal authorities and central governments in the Global South data and tools to help anticipate growth.

What’s often lacking in that scenario is follow through, Angel says. “These plans, typically funded with foreign aid, are prepared largely with knowledge and data that are not locally available and are then submitted as ‘deliverables’ to the local authorities, leaving them with the responsibility to implement them as they see fit after the consultants leave,” he explains. “It is no wonder that very few of these plans are ever implemented. There is typically no local ownership of the plans and little local understanding as to how they came about and how they can be changed when circumstances change.”

Gabiley, in Somaliland, is a small secondary city (2019 population: 31,000) that is growing and expanding rapidly. Like thousands of other cities in the Global South, it has no planning professionals, no planning data, and no resources for contracting planning consultants to prepare for accommodating its expected growth. The course materials, then, helped fill the gaps for its mayor, Mahamed-Amin Omar Abdi. After completing them, he said that “we not only have a long-term urban expansion plan for our city, but we also know how to do it by ourselves. And this is exactly what we need,” according to Angel.

In late October, Angel led a four-day workshop at NYU Africa House for nine senior land and planning officials from Malawi, the landlocked Southeastern African nation. The immediate objective of the workshop, sponsored in part by the Chandler Foundation, was to form a strong lobbying group that could chart and implement a plan of action for orderly, green, affordable, and inclusive urban expansion and densification there. Prior to attending, participants took the online course. “I went through the material twice. It all spoke directly and in practical terms to the problems we are facing here,” said Costly Chanza, the director of town planning of Blantyre, Malawi (2018 population: 800,000).


Blantyre is Malawi's commercial center.

Prof. Angel with officials from Malawi

Officials from Malawi came to NYU's Africa House for a workshop with Angel in October..

officials in suits looking at a map on a table

The course provides a realistic path of action at the ground level to make development practices less informal, create largely self-financing green expansion, and massively increase affordable housing while providing alternative means of livelihood for farmers facing the loss of their land. Course participants are asked to draft simple expansion plans for their cities, identify the land areas for expansion through 2050, design arterial road grids in the expansion areas, protect sensitive natural habitats, and lay out neighborhoods with verdant spaces.

Angel and partners from the World Resources Institute are now seeking funding for what they will call the Atlas of Urban Growth, a complementary tool to the online course that would provide online maps and metrics of successful urban expansions of the past, including topography and environmental hazards and assets. The Atlas would initially provide such data on all 5,000 cities and metropolitan areas of the world that now contain 100,000 people or more, and later for all 50,000 cities and metropolitan areas with populations of at least 10,000. Once completed, both the online course and the Atlas will be available and accessible free of charge in as many as 50 languages.