In recent years, the debate on urban sustainability has been active. It is often argued that in rich countries, the urban population uses resources more efficiently than the rural population.
In particular, people in rural areas use more energy for transportation and heating or cooling of detached houses. Therefore, people claim that urban life is more sustainable than rural life.
But in developing countries, we see a completely different picture. Studies in China and India show that people moving from villages to cities usually increases their resource consumption fourfold.
The reason is obvious: the traditional rural life there depends on the renewable resources available locally. In contrast, cities provide people with convenient access to fossil fuels and many other resources and products.
Rain forest
Urban and rural migrants will inevitably adopt a lifestyle dependent on mineral resources and long-distance food and timber supplies. Therefore, urban growth in developing countries is a major factor in the growing global environmental impact of mankind.
As far as the current situation is concerned, modern cities rely on continuous resource input from rural areas around the world. The sustainability of a city is inseparable from the sustainability of distant places.
China’s meat consumption is a good example. Since 1978, it has grown nearly tenfold, reaching 70 kg per person per year-similar to per capita consumption in Europe, but still lower than the figure in the United States.
But China is particularly important because of its large population.
As China’s own farmland is affected by soil pollution and urban development, most of the soybeans that feed Chinese farm animals now come from the Amazon basin, and the large number of fires that have recently occurred there is directly related to the continuous conversion of rainforest to farmland.
estuary
Therefore, urbanization has become a key factor affecting the health of the earth system.
Densely populated urban areas are also associated with the spread of disease from person to person, such as the Covid-19 pandemic.
Therefore, a new and comprehensive approach to planetary management is needed to meet these challenges. In our interconnected world, how do we solve these important problems?
Around the world, we often don’t care much about where the resources we use come from and where our waste ends up.
We often have vague ideas about the destination of solid waste, but we know very little about the liquid waste we wash away. The fact is that we have all contributed to the dead zones where hundreds of rivers on the planet enter the sea.
Biosphere
In addition to the nitrogen, potassium and phosphate contained in our food, mineral fertilizers and mud leached from farms are also part of the mixture, as well as industrial poisons.
If we take sustainable urban life seriously, we not only need to purify our sewage, but also ultimately need to return the nutrients contained in it to the farmland that provides us with food.
Our collective consumerism has become the main interface between man and nature. Our current actions are transforming the inherently renewable systems-soil, forests, rivers, coral reefs-into non-renewable systems.
These effects need to be addressed actively and actively. We must face the comprehensive impact of urbanized humans on the environment.
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, penetrate through the urban system, and then return to the biosphere in a degraded form.
example
Entropy prevails. As an inefficient and wasteful linear input and output system, urban metabolism needs to be transformed into a resource-efficient and renewable circulatory system.
There is an urgent need for a new comprehensive science of urban planning and management. However, recent books on the creation of a new urban science usually focus on the sorting and construction of the city’s internal environment, rather than a deep understanding of the relationship between the city and the external life world.
On a finite planet, economic and urban growth are inevitably restricted. The only way to overcome the concept of increasing scarcity is to allow cities to continuously renew the life systems on which they depend.
As cities become our main home, we urgently need to learn to abide by the laws of ecology. As suggested by the standards developed by Barry Commoner, the planning of new towns and cities and the transformation of existing towns need to undergo a profound paradigm shift. The following content is adapted from Barry Commoner, closed loop, 1971.
The four laws of ecology
Everything is related to everything else. All living things have an ecosystem, and what affects an ecosystem affects everyone.
Everything must go somewhere. There is no “waste” in nature, and there is no “waste” that can be thrown away.
Nature knows best. The lack of a certain substance in nature usually indicates that it is incompatible with the chemical reactions of life.
Everything comes from nothing. The development of nature is always accompanied by ecological costs, and these costs are huge.
In the world, different cities are at very different stages of development, and they always face different challenges.
Imagine
In Europe, North America and Australia, urban growth is now very limited, and the first task is to “ecologically transform” the urban system.
In the rapidly urbanizing countries of Asia, Africa and South America, urban development needs to be “smart from the beginning”: defined by high standards of resource efficiency, renewable energy is a key component.
Before modern times, cities with a population of 1 million, such as ancient Rome, were the largest human settlements in history. But today, an urban agglomeration with a population of 100 million has become a reality.
Nine cities in China’s Pearl River Delta, including Hong Kong, Guangzhou and Shenzhen, have developed to this scale.
The Chinese government is now envisioning another huge city cluster called Xiongan, which will integrate Beijing, Tianjin, and Hebei into an urban area with a population of about 100 million.
regeneration
How does this ambition match China’s widely publicized vision of creating an “ecological civilization”, mainstreaming the efficient use of clean energy, and using advanced environmentally friendly processes and materials?
“Clean” urbanization on this scale is technically possible, but the existing examples do not look optimistic. Rampant air, water, and soil pollution are related to the unprecedented urban industrial growth that has occurred in the Pearl River Delta.
Solving the regional environmental pollution and global ecological footprint associated with modern urbanization is a historic challenge.
On the positive side, vibrant new ideas often arise in cities. In the face of the upcoming earth emergency, the challenge we face is to use this creativity to rethink the city as a renewable and environmentally-friendly system, linking the personal well-being of urban residents with the collective interests of humans for the health of the earth. .
Only by mainstreaming renewable energy and protecting and continuously regenerating ecosystems and soil can cities become viable long-term homes for mankind.
This author
Herbert Girardet is the co-founder of the World Future Council and a member of the Club of Rome.His most recent book is Create a regenerative city (Routledge). Mr. Girardet is also the trustee of the Resurgence Trust, which owns and publishes The Ecologist.He will attend ZTE Reader Group November 15, 2021.
