The History and Future of Places – Part 14: Urban growth and decline over the coming century

The UN has measured populations of ‘urban agglomerations’ since 1950. Urban agglomerations include any place that is in some way urban, including cities, towns, informal settlements, suburbs and exurbs. At the global scale, the proportion of people living in such places will rise to almost 70% by 2050. This overall increase masks major differences between less and more developed regions.

Almost all future urban growth – about 95% – will occur in less developed regions. In Africa and Asia, about 2.1 billion people will be added to the urban population by 2050. This is equivalent to building 10 megacities the size of London or Jakarta every year for 30 years. In fact, several hundred much more modestly sized cities are already either under construction or planned, including more than 100 in India alone. Most are satellites of existing urban areas; they give a sense of what future places in new cities might be like.

China’s new cities seem to be the preferred model. Their identifying characteristics include skyscraper offices and apartment towers, wide boulevards with ample space for vehicles, and an emphasis on hi-tech industries. They contain moderately dense residential areas, both high and low-rise, and pay increased attention to sustainability issues and carbon emissions. However, questions remain as to whether these new cities are planned with local socio-economic realities in mind.

But new cities will only accommodate a fraction of projected population growth in less developed countries. Many more people will make their homes in informal settlements such as slums – defined by the UN as lacking running water, sanitation, infrastructure, and sufficient dwelling space. There have been remarkable recent accomplishments in reducing poverty across the developing world, but these have not been able to keep pace with population growth. Consequently, the scale of slums and informal settlements has actually expanded. In Nigeria, 42 million people currently live in slums, in India about 100 million. These numbers that can be expected to grow substantially. Often, these vulnerable populations live in regions where the consequences of climate change are expected to be especially harsh. 

The annual growth rate of urban populations in more developed regions has been declining for half a century. In the 1960s, when about 110 million people were added to cities and towns in Europe and North America, the annual rate of growth was 2%. It is now about 0.5% and expected to drop to 0.3% by 2040. In other words, overall urban growth in developed countries will slow to little more than a crawl by mid-century. If you live in a major European, Australian, or North American city, the skyline crowded with cranes and the ever-expanding suburbs may seem to bely reality. But most of the developed world’s limited population growth has been concentrated in the larger cities. This is perhaps because of the quality of their environments or their role in the network of world cities. Other places are stagnating. Selective urban growth is expected to continue and will happen even in countries where there will be overall population decline. It seems that bright lights are irresistible.

Where growth does occur, it seems unlikely that the character of urban places will alter quickly or significantly. This is partly because of enduring place legacies (discussed last week) and partly because the growth will be so slow. Current plans and policies will guide development along well-established lines for the next two or even three decades. Changes to built environments will be piecemeal and incremental, the result of individual projects. Their cumulative effects may, in due course, be considerable, but there is currently scant evidence that future places will hold any great surprises. In city centres there will probably be more densification with more tall apartments and bike lanes. At the urban fringes, there will be more place branded, master-planned suburban developments – especially around satellite cities. Unless something remarkable happens, personal motor vehicles of some sort will continue to be the preferred form of transport.

The greatest changes will be social and demographic. Populations will age considerably, with fewer workers supporting more retirees, fewer child-care centres, and more long-term facilities. Places will become more racially and culturally diverse, reinforcing the hybrid identities of urban neighbourhoods that have already developed in many world cities. Immigrants from less developed parts of the world will continue to make up for shortfalls in natural population increases. Social diversity has significant political and social consequences. In the U.S., the Census Bureau projects that, by 2060 the “non-Hispanic White population” will have shrunk by 19 million people. Over the same timeframe, the population of every other racial group will increase.

In regions and countries where immigration is not encouraged, such as Japan and Spain, or which are simply by-passed by growth, urban places will begin to shrink in population. The largest cities, such as Tokyo and Madrid, are expected to remain magnetic, and maintain or even increase in population size. Most other urban places will decline. Without radical changes in immigration policies and attitudes regarding racial differences, shrinkage will accelerate towards the end of century as people age in place and peak population looms.

There really is no precedent for understanding the consequences of shrinkage on this scale, nor its political and economic consequences. But recent instances of shrinking cities in the rustbelts of America and Germany give some indication. Shrinkage is likely to lead to boarded up buildings, abandoned neighbourhoods and failing infrastructure. In a few cases, such as Youngstown in Ohio, a smaller future has been accepted and strategies for greening abandoned spaces have been created. It is possible to imagine that, in the future, shrunken places could eventually be refashioned into smaller, demographically stable and environmentally sustainable communities.