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Urbanisation

The spread of megacity clusters requires infrastructure connections

Rural populations have been trickling into cities for decades as rural industries become more reliant on technology and require fewer workers. The move from rural to urban offers new employment options for young hopefuls. This trend has accelerated in recent years leading to unprecedented migration into urban areas.

Amie Silverwood, Content Manager - Communications and Media, RICS Americas
28 May 2019

Rural populations have been trickling into cities for decades as rural industries become more reliant on technology and require fewer workers. The move from rural to urban offers new employment options for young hopefuls. This trend has accelerated in recent years leading to unprecedented migration into urban areas.

As the migration from rural to urban proceeds, migration trends indicate that not all urban areas are equally attractive to urban migrants. By 2030, much of the global population will be concentrated in 50 megacity clusters throughout the world with 90% of urbanization occurring in the global South.

Cities are growing at an unprecedented rate. São Paulo and Mexico City took 15 years to grow to the size New York City grew in 150 years. Dhaka, Lagos and Kinshasa are now 40 times larger than they were in the 1950s. This growth brings opportunity and challenges as expanding cities require land and resources to support their sprawling populations.

Rural lands that once formed natural boundaries between cities are falling prey to the urban sprawl. Even political boundaries do not limit the growth of megacities. Rather, they cluster and merge across borders. As megacities grow, so does their influence and ability to attract more migrants. China already has four megacity regions of over 100 million inhabitants. Each cluster has a GDP of $2 trillion - almost equal to the GDP of all of India.

Economic implications of megacities

Megacity clusters are growing in economic and political importance but as populations and wealth become increasingly concentrated in megacities, entire countries and regions are at risk of becoming suburbs – economically dependent on one megacity. The African megacity Lagos has become the economic centre of West Africa drawing people and resources from well beyond the borders of Nigeria. Rather than the traditional dependency of a city on the nation in which it is located, megacities seek connection with other megacities to fuel their growth.

Parag Khanna, keynote speaker at the 2019 World Built Environment Forum Summit in New York City, has made it his mission to map the connections between megacity clusters and to observe trends that stem from these connections. His maps do not show the familiar political geography or natural geography but mapping the growth of megacities, Khanna is watching a shift to functional geography.

"If you map out the functional geography, you see how a set of cities that belong to different political geography has become a whole much greater than the sum of its parts," said Khanna. Infrastructure lines are more meaningful than political lines on a map. They trace the flow of opportunity from one megacity to another.

Reimagining the silk road

Cities become zones of opportunity as they link through roads, rail and air not unlike ancient trade networks along the silk road. Five thousand years ago, populations were connected by a web of city states. Trade networks brought people and goods across Asia, Africa and Europe.

As trade developed along the network of roads from ancient city to ancient city, emerging cities and regions along the way benefitted from being on the route. Likewise, as megacity clusters invest in infrastructure to facilitate the shipment of goods and bring in the resources needed by the urban population, prosperity is spread through the improvement of infrastructure. Khanna has termed these commercial ties between cities "diplomacity".

If you map out the functional geography, you see how a set of cities that belong to different political geography has become a whole much greater than the sum of its parts.

Parag Khanna

Facing the challenge of inequality

We are living off infrastructure built for a world of three billion as the world population heads to nine billion. To manage this growth in the world's population, we expect to build more infrastructure in the next 40 years than we have built to date. Falling behind on this task will drive instability.

Speaking at the Summit, Khanna pointed to inequality as the great challenge the global community must address in this decade – naming three kinds of inequality: international (North and South primarily), urban and rural and the inequality within cities themselves.

Inequality is driving political and social unrest and cities are becoming quite violent, noted Khanna referring to current populist movements. We see extreme disparities in wealth and life opportunities within cities. In some fragile cities, 75% of the population is under 30, often lacking education and jobs. But investments in infrastructure can spread opportunities to the disadvantaged.

"Asia has taken up the mantle of global infrastructure investment and it has been a key contributor to growth," explained Khanna. The IMF is no longer preaching austerity but has acknowledged the value of investing in infrastructure for growth. "The whole world is getting onto the agenda."

As countries invest in infrastructure, countries that have been poor in comparison are able to leverage it to grow. Khanna pointed to China's neighbouring countries as an example of the multiplier effect between infrastructure and growth. They may currently depend on China but as their economies diversify and accelerate, their governments gain confidence to appeal to a broader set of global investors.

An emerging threat

Despite the hope and opportunities that come with investment in infrastructure, climate change poses increasing risks from extreme weather and rising sea levels. Megacities are often clustered in low-lying areas that make them vulnerable to flooding - over 90% of urban centres are in coastal areas.

By 2030, climate change and natural disasters may cost cities $314 billion each year globally and could push 77 million more urban residents into poverty. Cities are currently in an infrastructure deficit that is worsening. If infrastructure doesn't keep up with the pace of growth, shortages will be exacerbated. Brazil has 20% of global water resources but 25% of Brazilians have chronic water shortages.

Megacities themselves pose a threat to the planet through the tentacles of the cities to the natural environment and all they consume from around them, said Khanna. He also pointed to the bottlenecks of social housing and connectivity. "If we make the right investments in connectivity, it makes the whole world more resilient."

Investments in connectivity lead to a stronger system by reducing blockages of energy, oil, water and other necessities from one megacity to another through alternative pathways. A world connected by a web is more resilient than one connected by a single thread that can be vulnerable to political or natural interference.

Moving forward

With higher investment in infrastructure, comes the need for a greater focus on resilience in the face of climate change and political unrest. Innovation in data applications allow for better mapping of demographic trends, better predictions of the effects of climate change and the impact of technology shifts on our built environment. Identifying high risk areas for flooding can trigger greater investment in flood defences and increased elevation of buildings and cooling systems. Having access to data and using data forecasting can quantify the value of resilience features and reinforce the value of ESG investing.

As megacities cluster and continue to grow, comes the need to reduce and reuse materials to shorten the tentacles that reach from megacities into their surrounding regions. We'll do this by retrofitting cities to anticipate the need for sustainability and lower costs, stressed Khanna.