Professor Edward Relph

We are still living in the age of enormous population growth that began in the late 18th century. In this time, the global population has expanded from just under 1 billion to about 7.8 billion today. However, the rate of growth seems to have peaked at about 2.2% a year in the 1960’s and has steadily declined since then. The current, lesser rate of annual growth (1.05%) is probably a result of programmes of population control and improvements in standards of living. Growth continues but ever more slowly, and this downward turn is unlikely to be reversed. For places, that is pivotal. For the first time, an end is in sight to the need for more places to accommodate more people.

Paralleling this reduction in rate of growth, has been an increase in life expectancy. In 1950 global life expectancy was about 50 years, roughly where it had been for much of human history. By 1970 it had risen to roughly 60 years and has now reached 73. In Europe and North America life expectancy is in the order of 80 years. To put it simply, populations everywhere are ageing. For places, this is significant because it means that they, too, are showing signs of ageing and decline.

Global population numbers mask considerable variations between places. About 90% of the worldwide increase of 4.0 billion since 1970 has occurred in Africa and Asia. There, places – especially towns and cities – have had to expand rapidly. Conversely, Europe has witnessed a remarkable drop off in levels of population growth. Since 1970, in many European countries the fertility rate has fallen well below 2.1 children per woman, the rate needed just to maintain an existing population. There is always a time lag before population totals begin to reflect changes in fertility rates. Nonetheless, without some intervention, populations will get older, there will be fewer young people, and overall totals will inevitably decline. Something similar has happened in Japan, Canada, and Australia. The US has so far proved to be the exception; its replacement rate has hovered just under 2.0.

“In many European countries the fertility rate has fallen well below 2.1 children per woman, the rate needed just to maintain an existing population. Something similar has happened in Japan, Canada, and Australia. The US has so far proved to be the exception.”

An ageing or declining population has significant consequences for economic growth. Immigration is the principal reason for the population growth seen in Europe and North America since 1970 (100 million and 150 million respectively). These are small increases, by comparison with the 3.7 billion in the rest of the world. But they have been sufficient to allow most cities, where the majority of immigrants tend to settle, to continue to expand. The cultural character of many of these cities has been transformed and diversified as a result.

Population growth over the last 50 years has been increasingly concentrated in urban areas. In 1970 the world’s urban areas held 37% of the world’s population. In 2020, that number is 56%.

As long as the rate of urban growth remains higher than the population growth rate, this urban intensification will continue. Again, these global numbers mask major variations. In Japan, 90% of the population lives in urban areas. In North America, 80%, while in most European countries it is between 70-75%. The population of Africa is still mostly rural.

There is another significant unevenness in urban growth. Over the last 50 years growth has mostly taken place in very large cities. In 1950 there were about 175 cities with populations over 500,000, accommodating 33% of the world’s urban population. By 1970, there were 335 cities home to populations over 500,000, housing 40% of all of the world’s urbanised people. In 2020, there are 1200 such cities, housing 57% of the urban population – one-third of the total global population.

In addition, the last seventy years have seen remarkable growth in megacities – cities with populations over 10 million. In 1950 there were just two such cities: New York and Tokyo. In 1970, there were three. Today, according to the UN World Urbanization Report, there are 34. Other sources, using different metrics, claim as many as 47. Whatever the number, the undeniable fact is that over the last 50 years large urban places have been getting larger and larger. The need to build upwards and outwards has created megalopolitan areas that are continuously built-up for 100km or more. One incidental consequence is that when we talk now of cities, we refer to entities very different from those relatively small places that have been considered cities throughout most of history.

Not all towns and cities in North American and Europe have shared in this growth. Even as most urban places have boomed, some have stagnated or declined – especially former industrial cities and remote small towns. Spain, for example, has recently been described as “hollowed-out” because much of the interior has been turned into a youth desert. Isolated small towns in France and Italy have almost no residents left, and in Canada entire rural settlements on the Prairies have disappeared.

The industrial cities in both North America and Europe that boomed from the 19th century through to the 1960s and 70s have declined. Manufacturing jobs have been shipped offshore and technologies have become obsolete. The population of Detroit has dropped from 1.8 million in 1950 to 700,000 now. This is an extreme example, but most rustbelt cities and old industrial regions have seen some decline or stagnation. In an age of low fertility rates and ageing populations, they are harbingers of the broader demographic phenomenon of shrinking cities. This is especially apparent in Japan, a nation which does not support immigration policies, has a fertility rate of just 1.4 and an ageing population mostly living in large cities. It is expected to experience a population decline of 20 million over the next 20 years. What will happen to neighbourhoods and streets as this happens remains a moot point.

“Most rustbelt cities and old industrial regions have seen some decline or stagnation. In an age of low fertility rates and aging populations, they are harbingers of the broader demographic phenomenon of shrinking cities.”

I believe we are witnessing the emergence of urban place inequality. It has developed in the current context of continuing population growth, ageing populations and economic transformation, and is manifest at global, national and regional scale. At one extreme are cities that are so attractive they have developed great gravitational force. They pull in ever more people; the bigger they get, the more people they attract. Then there are all the other places. Some are still growing and changing, but only relatively slowly. Others have slipped into decline as people have drifted away, businesses have closed and buildings have been left abandoned.