As global demand for energy grows and prices rise, a city’s energy consumption becomes increasingly tied to its economic viability, warns the author of The Very Hungry City. Austin Troy, a seasoned expert in urban environmental management, explains for general readers how a city with a high ‘urban energy metabolism’ – that is, a city that needs large amounts of energy in order to function – will be at a competitive disadvantage in the future.
In this article, Yale author Lyric Hughes Hale explores the possible repercussions of population redistribution and considers whether the world’s megacities can support their increasingly gargantuan number of residents.
Emerging markets are driving global growth, and 3.5 billion people are moving to cities. That’s $20 trillion of infrastructure to lay down. It’s either a big problem or an opportunity.
-Peter Henry, dean of NYU’s Stern School of Business, New York Times Magazine.
Global investors have focused on the opportunities offered by urbanization in emerging markets. But some observers have begun to imagine the potential negative effects of billions of unskilled people moving from rural areas to already polluted cities, pushing groaning infrastructures to their limits.
In fact, in almost all post-apocalyptic visions of the end of civilization, earth’s remaining inhabitants struggle to survive in the countryside, outside of destroyed, dangerous, or smoldering urban areas. There is good reason to worry about the sheer density of modern megacities when faced with threats such as nuclear catastrophe, acts of war and terrorism, disease, pollution, or simply a lack of critical natural resources such as water and clean energy.
Today, half the world’s population lives in cities that take up only 2.7% of the earth’s available land. Yet in spite of potential threats and bottlenecks, the pull of urbanization has been so compelling that for the past 100 years rural-urban migration been recognized as a major component of world GDP growth. In emerging countries, urbanization rates are often used to measure relative stages of economic development.
But might we be approaching the limits of the benefits of mass migration from farm to city? Is the goal of economic development a world in which most people live in cities, supplied by huge mechanized farms, and entertained by bucolic landscapes they visit upon occasion? Is the natural end of economic growth a society that is 100% urbanized, or is there an optimum balance of rural and urban population density?
An underlying assumption of urbanization, that land and housing prices in major urban areas could only increase, was the origin of the Global Financial Crisis. However, given the right mix of circumstances and mismanagement, urbanization can be reversed–witness Detroit. Back In 1500, Beijing was the most populous city on earth. Then came war, turmoil, famine, and isolation, and China’s urban population increased only half a percentage point from 1600-1900—a period of over 300 years. After the 1949, and the Cultural Revolution, which brought the banishment of huge populations to the countryside, China was still very much a rural society.
Top 10 Cities of the Year 1500
|6||Constantinople (Istanbul), Turkey||200,000|
|10||Nanjing, China Source: Four Thousand Years of Urban Growth: An Historical Census by Tertius Chandler. 1987, St. David’s University Press.||147,000|
Twenty years ago, South Africa’s cities were braced for a massive influx of rural migrants following the scrapping of apartheid-era pass laws which had restricted black people’s movements. Cities such a Johannesburg and Durban have indeed grown, but not at the phenomenal rates projected and others have hardly grown at all. Although investors might dream of construction cranes and new New Yorks being built weekly, governments in developing countries are now warning that the flood of new urban citizens must be slowed. Uzbekistan, North Korea, and a host of African countries are attempting to slow their rates of urbanization. Circular, or reverse migration has in fact occurred in some parts of Africa already. According to IRIN, a UN news agency:
According to Deborah Potts, a reader in human geography at King’s College London, similar patters of circular migration are playing out in many African countries, countering the effects of rural-urban migration and confounding the widely held assumption that the continent is urbanizing rapidly.
In other countries, urbanization is accelerating, but at a harmful pace. Pakistan is an extreme example of urban dysfunction and inadequate infrastructure. Its projected urban growth rate is the highest in the world, and is set to increase from 75 million to 200 million by 2050. Currently, half of the people living in its cities live in slums. At the same time, Pakistan’s rural population will increase from 175 to 325 million. How is this possibly sustainable in one of the poorest and most politically unstable countries on earth? Given the dangers, who will dare to invest in and build its infrastructure? How can these new megacities afford the energy they will need to support this level of population growth, to name just one resource?
Yale Press has published a new book, The Very Hungry City that focuses on the energy and resource requirements of modern cities. The author, Austin Troy, lives in Vermont, which is the East Coast center of the green movement in the United States. Prof. Troy is an expert in spatial analysis and in using GIS (Geographic Information Systems) in order to understand urbanization and the urban environment. He uses these tools to analyze energy use in cities, something he calls ‘urban energy metabolism’.
The most compelling conclusion of the book is that there is a ‘sweet spot’ of urban development, an optimal mix of various services including public transportation and energy, which together create a benign state of economic efficiency as well as a smaller carbon footprint. Obviously, achieving such a state requires intelligent policies, and I believe that Prof Troy is correct to focus on best practices. Urban planning is not just a matter of targeting optimal population size. At the heart of optimal development there has to be optimal information. Size doesn’t really matter, data, in conjunction with a stable political system that can effectively utilize this information, does. The cities that are able to do this will thrive, those that cannot will not be able to compete. According to Troy:
…I believe that communities committed to restructuring themselves for energy efficiency will be at a big advantage over those that do not. If changes are put in place correctly, they will also make cities more desirable, vibrant, aesthetic, and healthy places to live.
I hope that Pakistan’s leaders read Prof Troy’s book. There is a wealth of academic literature on cities they should be adding to their libraries. Cities are central to all major civilizations, beginning with Ur in Mesopotamia, and now the megacities (a la Blade Runner) that are challenging national governments. But according to Brendan O’Flaherty, author of City Economics, ‘one of the oldest reasons cities were built: military protection’ perhaps no longer applies. In fact, dense populations and their interconnecting transportation systems are the key target of terrorist groups. Cities can no longer be protected by a wall—as were the ancient cities of Beijing and Baghdad. Their purposes and relative advantages have changed.
One could argue that the key threat to cities today is internal—overpopulation. A world where population growth is highest where poverty is greatest is not a recipe for peaceful and prosperous cities. However, this growth could be slowing faster than anticipated.
- Article by Lyric Hughes Hale
Lyric Hughes Hale is a writer and contributor to a range of publications, including the Financial Times, Los Angeles Times, USA Today, Current History and Institutional Investor.
What’s Next? Unconventional Wisdom on the Future of the World Economy by David Hale and Lyric Hale is available now from Yale University Press.