The United Nations (UN) tells us that more than half of the world’s population, 54 per cent, lives in urban areas.
And projections show that increasing urbanization coupled with overall population growth is likely to add another 2.5 billion urban dwellers by 2050.
The UN researches all manner of things and publishes fascinating reports. The reports sound warnings, but often don't offer many solutions.
So the world's urban population is expected to surpass six billion by 2045. So?
So all those people will need to be housed. They'll need clean water to drink, clean air to breathe. And every morning when they wake up, they'll want breakfast.
Today's cities — already large — will continue to grow, so by 2030, 60 per cent of the world's population is expected to live in mega-cities. That's just 14 years from now.
The UN defines a mega-city as having 10 million or more residents.
In 1990 there were 10 such cities with a total population of 153 million. By 2014, there were 28 mega-cities, home to 453 million. By 2030, there will be 41 mega-cities.
Largest of them all is, and will be, Tokyo, with 38 million inhabitants. Delhi is next with 26 million, Shanghai with 23 million and Mexico City, Mumbai and São Paulo, each with around 21 million inhabitants.
In the face of these projections, John Wilmoth, director of the UN's population division, says that "managing urban areas has become one of the more important development challenges of the 21st century.
"Our success or failure in building sustainable cities will be a major factor in the success of the post-2015 UN development agenda."
If he's right, how all these people live and what their lives will be like will depend on important choices made by leaders now and in the next few years.
A good place to start might be hard infrastructure: water filtration plants, wastewater plants, roads, rail lines, airports, harbours, stuff like that. Then social infrastructure: hospitals, schools, universities, research facilities.
Don't forget smart technologies that promise to give us smart cities.
Lots of people have been working on that for years now. The people they hope to sell their products to are sometimes classified as "early adopters," the 'technogeeks' who feel they simply must have the latest gadgets.
This leads to something I worry about: Are we going to have smart cities that only benefit the early adopters? Or the wealthy? Or are we going to have smart cities that benefit everyone?
Technologies exist that have the power to help people live in communities that are more responsive to their needs and that can actually improve lives. More are being tested every day. Some show great promise, providing that they can be scaled up.
I'm not talking about a utopian vision of life, like on The Jetsons. I'm talking about real urban communities responding in real time to changing weather, times of day and the needs of their residents. These technologies can span entire cities. They can monitor traffic to keep cars moving efficiently, or warn residents when pollution levels climb.
That's the sort of thing we should mean when we talk about smart cities.
Smart cities are, at least in part, a response to incoherent infrastructure design and urban planning in the past. Smart cities promise real-time monitoring, analysis and improvement in city decision-making.
Talk to smart city enthusiasts and they'll tell you that smart cities will improve efficiency, environmental sustainability and citizen engagement.
They are big investments that are supposed to drive social transformation.
But the time for making the necessary decisions is now and the next few years. It's not a big window, but if we try, we can make it before the peaceful suburb where you live becomes part of another congested, polluted mega-city.
We don't need smart cities for technogeeks. We need smart cities for the folks next door.
Korky Koroluk is an Ottawa-based freelance writer. Send comments to email@example.com.