This aerial view of Hanoi, Vietnam, clearly shows areas of decreasing density between the city and the countryside, making it hard to define the limits of the "urban" area.
In everyday usage, terms related to human settlements have vague, shifting meanings. What one person might describe as a small ‘city’ might be a ‘town’ or ‘village’ for someone else; one person’s ‘megacity’ might be a cluster of cities from a different perspective. Similarly, we can usually identify areas that are clearly within a city and others that are outside it, but there is usually a peri-urban area of intermediate density that usually lies between the two, making it hard to define a clear city limit. Formal administrative boundaries may have historic or political meaning, but are rarely aligned with the physical or economic extents of the urban area.
What exactly is a city? It depends who you ask
It turns out there is no standard international definition of an ‘urban’ area or ‘urban’ population. Each country has its own definition, and collects data accordingly. The statistic that 50% of the world’s population is urban is arrived at simply by adding up these incomparable, and sometimes conflicting, definitions.
When we think of urban expansion in the 21st century, we often think of ‘sprawl’, a term that calls to mind low-density, car-oriented suburban growth, perhaps made up of single-family homes. Past studies have suggested that historically, cities around the world are becoming less dense as they grow, which has prompted worries about the environmental impacts of excess land consumption and automobile dependency. A widely cited rule of thumb is that as the population of a city doubles, its built area triples. But our new study on urban expansion in East Asia has yielded some surprising findings that are making us rethink this assumption of declining urban densities everywhere.
- population growth
- sustainable urbanization
- East Asia urban expansion
- population density
- Urban Development
- East Asia and Pacific
- Lao People's Democratic Republic
- Taiwan, China
- Korea, Democratic People's Republic of
- Korea, Republic of
You cannot imagine my surprise while reading a BusinessWeek article last July about an innovative way to transform India’s litter into partial substitute for bitumen in asphalt to build roads!
Well, this transformative method arguably holds larger potential than the “garbage to music” recycling approach I recently wrote about in my first post about creative ways to manage waste. “Garbage to roads” was pioneered by an Indian chemist called Vasudevan, and it could help not only in getting rid of tons of plastic litter- thick acrylics and bottles, grocery bags and wrappers-- but in building roads at the same time. It’s a win-win solution for all.
In September 2013, World Bank Group President Jim Yong Kim launched the Low Carbon, Livable Cities (LC2) initiative at the Clinton Global Forum in New York City. Here we are, a full year later, with the UN Climate Summit upon us, and it’s clear that the Bank’s efforts are bearing fruit, strongly influencing or linking neatly with efforts being announced today.
The growth of large metropolitan areas around the world has been very recent and very rapid, particularly when measured against the duration of human beings’ existence as a species. For the first 95% of our time on earth, we built no settlements at all. Cities of a million people arose during only the last 1% of homo sapiens’ time on earth, and there are already 500 such cities in the world today.
If we have spent most of our existence as small wandering bands, does that mean we are ill-equipped to manage urban settlements of this vast size? The key to success in our current urban transformation may in fact be the same as the key to mankind’s earliest origins - our ability to cooperate.
I started working in solid waste management only a few months before I heard the story of the children’s orchestra in Paraguay, called the Orchestra of Recycled Instruments of Cateura.
These talented and driven children, all from poor families, had the creativity to construct musical instruments from recycled materials and use them to play classical music (check out the video “Landfill Harmonic”). The passion of these musicians, inspired by their unique social, educational and artistic influences – as well as constraints – and their ability to create art from limited resources strengthened my commitment to the work we do in solid waste management.
An entry in a recent Action4Climate video competition, “Climate TV, City Climate” highlights some of the issues cities are facing and how green infrastructure solutions can help a city cope with increased heat and stormwater run-off.
Cities have been experiencing a moment in the cultural spotlight in the last few years. There is more discussion and even celebration of cities than ever before. Newspapers and magazines are starting websites dedicated to global urban issues, university researchers and technology companies are turning their attention to ‘smart cities’, and there are even popular documentary movies, reality shows and musicals all about city planning. India, still mostly rural, has just elected a new Prime Minister who promises urban redevelopment and ‘new-age cities’, and it is no longer shocking to hear that China's proposed urbanization budget runs in the trillions of dollars.
Why has this urban moment come about now? Several trends, some in the developing world and others in wealthier countries, seem to have converged lately. It is interesting to step back and examine these trends, before thinking about where we go from here.
While many may have heard the statistic “Cities are home to 50% of the world’s population”, few realize that it leads directly to a sobering and much less hyped conclusion: we face an urgent need to understand how our cities work.
Cities are now the defining human organizational structure on earth, but what do we know about these creations? Sadly, not enough. Which is why collecting and disseminating high-quality data about cities and how they function is of critical importance.
Carbon Disclosure Project (CDP) has recently taken a giant step in this direction by making our 2013 data set on over 100 large cities, their greenhouse gas emissions, and their actions on climate change available for free download in CSV files via our website. This effort—made possible by a grant from Bloomberg Philanthropies and our long-term partnership with C40—brings our voluminous data into the public domain for the first time.