Humanity is facing an existential contradiction: we are building an urban future for ourselves, yet urbanisation in its current form is threatening the very future of humanity and the natural world. Urban growth is a seemingly unstoppable worldwide process.
Much has been written about this historic trend, but the environmental impacts of an urbanising world are barely discussed.
The urban age is upon us. Since the 1950s thousands of new cities of unprecedented size have sprung up on earth, often on the sites of existing villages and small towns. Under current trends, three quarters of an unprecedented human population will be urban by 2050, yet few questions are being asked about how this could affect the wellbeing of their inhabitants and of the global environment.
We are faced with a wide range of issues – from overcrowding to crime and pollution, to loss of precious farmland, and to ever greater demands for natural resources.
Whilst urban-centred communication, transport and trading systems connect humanity as never before, they are also causing ever-larger global ecological footprints and environmental externalities.
As ever larger and more resource-hungry cities proliferate, are we risking long-term human well-being and even survival? Can we create resource efficient urban systems within the carrying capacity of planet earth? What measures could achieve such positive outcomes?
The twentieth century was the age of the ‘great acceleration’ - directly linked to global urbanisation and ever-increasing resource use on a finite planet: world economic output grew 40 times, fossil fuel use 16-fold, fish catches grew by a factor of 35, and human water consumption grew nine-fold.
In 2019, CO2 concentrations exceeded 400ppm for the first time. Global warming well beyond 1.5 degrees is now almost certain, with severe repercussions for human and non-human life across the world.
What could a fully-fledged urban future look like? China is offering a tantalising glimpse, with half a dozen megacities and hundreds of million-plus cities having emerged there.
The Chinese government has now embarked on the creation of Xiongan, aiming to merge Beijing, Hebei and Tianjin into an urban area of some 110 million. This project was preceded by developments in the Pearl River delta: the Hong Kong-Shenzhen-Guangzhou urban region, a prime industrial location, now ‘home’ to over 100 million people. But what of the environmental impacts of this?
Much of the urban-industrial growth there has taken place on rice paddies, resulting in the paving over of rich farmland as well as major soil contamination problems. 44 percent of rice samples in Guangzhou were found to contain poisonous levels of cadmium, primarily from factory emissions. Some 50 percent of soils in the Pearl River delta was reported to be severely contaminated.
The Chinese government is increasingly aware of the imperative of creating resource efficient and non-polluting urban areas.
Xiongan is intended to be a livable and green city, aiming for 100 percent clean power, utilising advanced environment-friendly and energy-saving materials and techniques.
Two main factors have driven global urbanization: unprecedented access to fossil-fuels and the rules of neoliberal globalisation. These factors are transforming the lives and behaviour patterns of billions of people.
As centres of economic power and social interaction, and of both production and consumption, the world’s cities have a magnetic attraction.
But urban growth, up till now, has been feasible only through massive, continuous injections of fossil fuel energy, with major implications regarding climate change.
Tianjin, part of the Xiongan city cluster, is listed as just one of nine of China’s large coastal cities particularly vulnerable to sea level rises. Many other cities in Asia, Europe and America are similarly threatened. Their energy demands could ultimately cause them to become primary victims of their own success, both, in regarding urban temperatures as well sea level rises and flooding.
Meanwhile local air pollution problems due to fossil fuel burning have been widely reported in many of the world’s large cities, with significant consequences for local populations. And there is another looming threat: is the concentration of people in dense urban areas also implicated in human-to-human disease transmission?
The current age of Anthropocene is also the age of the city: urban areas are the world’s economic powerhouses, in which 80 percent of global GDP is being produced.
Many people celebrate cities as a triumphal human achievement, perhaps most notably Edward Glaeser in his book, The Triumph of the City (2010).
Modern cities of millions of people are certainly an astonishing undertaking. They are centres of innovation as well as economic activity, superior education and health services. Investors favour them since they offer a plethora of services at low per-capita cost. Governments like cities because they are a reliable source of tax revenues.
But could global urbanisation also be a tragedy in the making? Whilst cities are built on only three to four percent of the world’s land surface, the ecological footprints cover much of the earth’s productive land.
The aggregated environmental impacts of an urbanising humanity have to be faced head-on: our resource demands now substantially exceed the earth’s regenerative capacity. In 2019, humanity used more natural resources in seven months than the earth can produce in a year, substantially overdrawing nature’s income and running down its stocks of 'capital'.
Under current trends, two earths will be needed to supply us with biological resources by 2030.
Meat consumption is becoming a particularly important issue in an urbanising world. China’s consumption is a case in point. It grew nearly tenfold, to 70 kgs per person since 1978, similar to per capita consumption in Europe, but still much lower than US figures.
But China matters disproportionately because of its vast population. As China’s own farmland is compromised by the impacts of urban growth, the bulk of the soybeans feeding China’s farm animals now originate from the Amazon basin, and the vast recent fires there are directly connected to the continuing conversion of rainforest into farmland.
Urbanisation, then, has become a key factor shaping the earth system. As things stand, modern cities rely on a continuous input of resources originating from rural areas across the world.
The sustainability of cities is inextricably linked to the sustainability of distant places. A new, integrated approach to planetary stewardship is therefore required to address these challenges.
How can we address these vital issues in our interconnected world?
In recent years there has been an active debate about urban sustainability. It is often argued that in affluent countries city people use resources more efficiently than rural populations.
In particular, rural people use more energy in transport and in heating or cooling detached houses. Urban living is therefore claimed to be more sustainable than rural living.
But we see a very different picture in developing countries. Studies from China and India show that people moving from a village to a city will, typically, increase their resource consumption four-fold. The reason is quite evident: traditional rural living there was reliant on locally available renewable resources; cities, in contrast, offer people easy access to fossil fuels and many other resources and products.
Rural-urban migrants will inevitably adopt lifestyles dependent on mineral resources as well as long-distance food and timber supplies.
Urban growth in developing countries is therefore a major factor in humanity’s ever growing global environmental impacts.
Across the world, we tend to have little concern about where the resources we use originate and where our wastes end up. We tend to have vague notions about destination of our solid waste, but know little about the liquid wastes we flush away.
We all contribute to the hundreds of dead zones in river estuaries across the planet. In addition to the nitrogen, potash and phosphate that our food contains, mineral fertilisers and slurry leeching from farms are also part of the mix, as well as industrial poisons.
If we are serious about sustainable urban living, we need to not just decontaminate our sewage, but ultimately return the nutrients it contains back to the farmland feeding us.
Our collective consumerism has become the main interface between humans and nature. Our actions are currently turning inherently renewable systems – soils, forests, rivers, coral reefs – into non-renewable systems. These impacts need to be vigorously and positively addressed.
Cities have a quantifiable metabolism: energy and materials – carbon, nitrogen, phosphorus, metals, water, industrial products – enter the city from the biosphere and the global economy, and percolate through urban systems before returning to the biosphere in a degraded form. Entropy prevails.
The urban metabolism, which currently operates as an inefficient and wasteful linear input–output system, needs to be transformed into a resource-efficient and regenerative, circular system.
A new integrated science of urban planning and management is urgently needed. Yet recent books on creating a new science of cities are generally concerned mainly with ordering and structuring the intra-urban environment rather than with developing a deeper understanding about the relationship between cities and the living world beyond.
On a finite planet there are inevitably limits to economic and urban growth. The only way to overcome notions of ever greater scarcity is for cities to continually regenerate the living systems on which they rely for their sustenance.
With cities as our primary home we need to learn to comply with the laws of ecology. The planning of new towns and cities, as well as the retrofit of existing ones, needs to undergo a profound paradigm shift, as implied by criteria developed by Barry Commoner.
Commoner's four laws of ecology states that, chiefly, everything is connected to everything else. There is one ecosphere for all living organisms and what affects one affects all.
Secondly, everything must go somewhere. There is no ‘waste’ in nature and there is no ‘away’ to which it can be thrown.
Thirdly, nature knows best. The absence of a particular substance from nature is often a sign that it is incompatible with the chemistry of life.
Finally, nothing comes from nothing. Exploitation of nature always carries ecological costs and these costs are significant.
In recent years there have been a great many urban regeneration projects in run-down cities of industrialised countries. These have greatly benefitted many people.
But in my writing I have concentrated on the concept of 'regenerative cities', focussing on the linkages between urban systems and ecosystems.
Regenerative development is about assuring a proactive relationship between an urban humanity and the world’s ecosystems, and nurturing nature’s dynamism and abundance whilst drawing on its income.
Crucially, we need to help regenerate soils, forests and watercourses that our cities depend on, rather than just accepting that they are ‘sustained’ in a degraded condition. And, of course, the climate emergency needs to be dealt with, above al else, at the level of urban energy consumption.
We urgently need to deal with the environmental externalities of an urbanising world: mainstreaming renewable energy; restoring biodiversity, ecosystem resilience and healthy soils; countering soil erosion; reforesting watersheds and mangroves; restoring water tables and addressing water pollution.
Regenerative urban development, then, is about a restorative relationship between cities, the natural world and future life. Adoption of appropriate policies, technologies and business practices, can address these issues and help build vibrant new local green economies.
Across the world, different cities are at very different stages of development, and invariably they face different challenges. In Europe, North America and Australia, urban growth is very limited and the primary task is to undertake ‘ecological retrofits’ of urban systems.
In rapidly urbanising countries in Asia, Africa and South America, urban development needs to be ‘smart from the start’: defined by high standards of resource efficiency, with renewable energy as a key component.
Can city regions of 100 million people be beacons of the ecological civilisation that countries like China are now proclaiming? Yes, urbanisation on this scale may contribute to further reducing poverty, but what about the ecological footprints of such megacity clusters?
Much can be achieved by reducing the global ecological footprints of cities. The rapid current growth of urban agriculture, including vertical farming using LED lights, can significantly contribute to urban food self-reliance. But when it comes to grains and animal feeds, large external land surfaces will always be required.
It is in cities where human creativity is most vibrant, where new ideas are often generated, where most political, economic and financial decisions are taken.
Now the challenge is to utilise this creativity to reshape cities into regenerative, environmentally beneficial systems.
Understanding the environmental implications of an urbanising world requires the evolution of a new practices, linking the wellbeing of individual urban citizens with humanity’s collective interest in the health of our home planet.
Only by relying on regenerative energy resources and by continuously regenerating ecosystems and soils from which they draw their sustenance can cities be a viable long-term home for humanity.
In my book, Creating Regenerative Cities, I have tried to outline problems as well as solutions. Twenty case studies show where significant initiatives on creating regenerative cities are taking place.
Professor Herbert Girardet is co-founder of the World Future Council and an executive committee member of the Club of Rome. For many years he has focussed on the implications of an urban future, working as researcher, author and consultant. His four books on urban futures are: The Gaia Atlas of Cities (1992); Creating Sustainable Cities (2001); Cities, People Planet (2004); Creating Regenerative Cities (2014). Professor Girardet is a trustee of the Resurgence Trust, owner and publisher of The Ecologist.
Image: LhcCoutinho, Pixabay.