This UN report (2018) on urbanization trends is a fascinating way to understand how our world is growing and changing. So today's post is about some of my takeaways. If you have others, feel free to add them to the comment section below.

But first, some definitions.

The UN report considers 3 ways to measure the size of a city, all of which we have used before on this blog. The first is the "city proper." That is the current administrative boundary of a city. The second is the "urban agglomeration" area, which is a city's contiguous built-up area. And the third is the "metropolitan area," which is the approximate area of economic and social interconnectedness.

Above is what these 3 boundaries might look like for Toronto (which is the example they use in their report). About the only one that isn't debatable is the "city proper" boundary; but it really doesn't capture the full extent of a city. Wherever possible, the UN report relies on the city's urban agglomeration area. They also define a "megacity" as a city of over 10 million people.

The largest city in the world is currently Tokyo. However, from 2018 to 2030 it is expected to decline by almost 900,000 people. Whereas, the city in 2nd position -- Delhi -- is expected to add more than 10 million inhabitants during this same time period. By 2030, these are expected to be the largest cities in the world:

Most current megacities are located in what the UN refers to as the "Global South." And 9 out of the 10 cities projected to become megacities by 2030 are located in developing countries. The one exception is London. Though all regions in the world are becoming more urban, the real population growth is happening in Asia and Africa.

Most cities -- 59% of cities with 500,000 or more people -- are at risk of at least one natural disaster. And 3 megacities -- namely Manila, Osaka, and Tokyo -- are high risk for 3 or more types of natural disaster.

Going through the report's data charts, it's also interesting to note that Toronto is not projected to become a megacity by 2030. However, the Toronto area already represents over 20% of Canada's entire urban population.

In the United States, Chicago's urban agglomeration is projected to continuing growing and does come close to megacity status by 2030. The Miami region is similarly expected to grow and is actually right on top of Toronto in terms of population. But the fastest growing regions are, of course, expected to be the city's that can more easily sprawl (Las Vegas, Phoenix, and so on).

Bogotá, Colombia is already a megacity and is expected to add almost 2 million people by 2030. It currently represents about 26.5% of the country's entire urban population. São Paulo remains one of the top 10 largest cities in the world and is similarly projected to add over 2 million people in the same time period, but to a much larger base.

In Europe, it's London, Paris, and Moscow, with the latter two already in possession of megacity status.

Now quantity isn't everything. Despite not ranking in the top 10 in terms of population, both New York and London are widely considered to be the world's preeminent global cities. At the same time, we do know that the size of a city does create certain socioeconomic benefits. Urban agglomerations create agglomeration economies.

If you'd like to download a copy of the World's Cities in 2018 (United Nations), click here.

Charts/Maps: United Nations

Here's a chart from Knight Frank's 2019 Global Affordability Monitor that I think you'll find interesting:

It compares real home price growth and real household income growth (after tax) over the last 5 years for 32 world cities. The bolded percentages represent the former and the non-bolded percentages represent the latter.

Consider the variations here.

Amsterdam saw a real home price change of 63.6%, but a household income change of only 4.4% (although the circle looks to be in the wrong spot if this number is correct).

Moscow, on the other hand, saw flat home prices (0.1%) and a 22.7% increase in household income.

Though San Francisco is the star in terms of income growth.

Sao Paulo, unfortunately, saw a dramatic decline in both home prices and incomes. It's in the bottom left corner.

When I look at this chart, I don't see a strong correlation between household incomes and home prices. And the proportions of the chart tell you that the y-axis is moving more than the x-axis.

But if the top number exceeds the bottom number, then you could come to the conclusion that housing affordability has gotten worse over the last 5 years.

Generally speaking, architects are the only people I know who like Brutalist architecture. In fact, architect, professor and author Witold Rybczynski once proposed the following litmus test to determine whether a building is indeed an example of Brutalism: "If people don’t hate it, it can’t be Brutalist."

But as I have argued before, sometimes architectural styles take a bit of time to settle in and become fully appreciated. Consider how improbable it would seem to demolish a beautiful old Victorian home today. And yet Toronto, and countless other cities, did this on many occasions. Regent Park, Toronto was once Cabbagetown South.

Brutalism also took on different sensibilities around the world.

I love this recent piece in T (NY Times Style Magazine) by Michael Snyder called, "The Unexpectedly Tropical History of Brutalism." In it he uses the term "Equatorial Brutalism" (a new one for me) and discusses the "surprising apotheosis" of Brutalism in equatorial countries (and in particular Brazil). It is a good follow-up to my recent post on Oscar Niemeyer's work.

So here's an excerpt from Michael's article. If you don't already like Brutalism, maybe it'll get you a little bit closer.

What these buildings shared, beyond an aesthetic — though they shared that, too, with their radical porousness, their blunt geometric forms and their extensive use of raw concrete — was a commitment to architecture as an instigator of progress. But in the tropics, Brutalism reached an unexpected apotheosis: Infiltrated by lush plants and softened by humidity, buildings that looked cold and imposing against London’s constant drizzle or Boston’s icy slush were transformed into fecund, vital spaces. Concrete surfaces bloomed green with moss. The panels of glass necessary for sealing rooms against the northern chill either disappeared or receded from view, encouraging cross-ventilation while also protecting interior spaces from direct sun. The openness and transparency that the Smithsons had pronounced became a practical reality in these humid environments, both theoretically and literally: Built from inexpensive, readily available materials, equatorial Brutalism was as accessible and functional as it was symbolically potent, resulting in buildings that would define new societies growing around them like vines. Here, Brutalism wasn’t only an architecture that shaped the future or confronted the past — it was an architecture of freedom.

Photo by Samuel Zeller on Unsplash