Sustainability and quality of life in large cities

Observatory of Tomorrow
Sustainability and quality of life in large cities

*Cristina Mendonça

Is it possible to increase sustainability and quality of living in cities, while the number of inhabitants is still increasing? Definitively, yes. Low-carbon, compact, connected and coordinated cities are the most efficient and effective way of welcoming the population boom. Community-centric cities, embedded with green infrastructure, boost resource efficiency, facilitate innovation and promote vibrant urban spaces. 

You may wonder how cities can increase their sustainability if the world’s urban population is expected to nearly double by 2050, representing almost 70% of the projected global population of 9.5 billion. How will resources be provided? 7.3 billion people today are already stretching our planetary boundaries. Further, climate change and biosphere integrity (resource depletion) are putting Earth Systems and human development at risk. When we take into consideration the gap in our social divide, where 1.1 billion people do not even have access to electricity, to cite just one example, the above question seems unsolvable. 

But is it really the increase in population (particularly, urban population) that has brought us to this crossroads? Are we really facing a scarcity problem? The answer is no.

I invite you to see these challenges from a different perspective, as evidenced from the food sector – a complex system, encompassing individual, social, cultural, economic, environmental and political dimensions.

Roughly 24% of food calories produced for human consumption is lost or wasted globally, between the farm and the fork.  Even after accounting for this huge loss, at the global aggregated level, the food supply, in terms of per capita calories provided, is still adequate. Over the last decade, the number of calories produced for human consumption has actually increased more than 40%, while the global population has only increased 28%. Yet, undernourishment is still a reality for 800 million people. On the other hand, in 2014, more than 1.9 billion adults were overweight. Of these, more than 600 million were obese. Overweight and obesity kills more people than being underweight. 

Our global food system has also been generating severe environmental impacts, directly related to our own dietary habits. Research indicates that consumption from households contributes to more than 60% of global greenhouse gas (GHG) emissions and between 50% and 80% of total land, material and water use. And food, in particular, the consumption of animal products, is one of the most impactful.

These unbalanced numbers show us that the underlying challenge is not one of resource scarcity or population growth, but rather a “materials in-the-wrong place problem,” a question of human consciousness and how we operate. A matter of our capacity to recognize that our “private” consumption patterns turn out to be a “public” issue. It is our worldview that limits our sense of interconnectedness between each other and with our planet. 

This is the backbone toward promoting a “profound urban paradigm shift, grounded in the integrated and indivisible dimensions of sustainable development: social, economic and environmental,” which is the main commitment stated in the New Urban Agenda, adopted this week by nation states in Quito at HABITAT III, a UN Conference on Housing and Sustainable Urban Development.

To forge this path will require each of us, individually and collectively, to step-up to our full potential in a radical transformative way. Mayors and city leaders are in the beginning stages of co-creating and forging this new path in collaboration with their citizens, other governments, private sector, banks, civil society, academia and other stakeholders. Mayors of the C40 Cities Climate Leadership Group have already begun to transform their cities.

The city of Los Angeles, a pioneer in implementing large scale LED streetlight retrofit, conceded a portion of electricity savings when selecting the LED fixture, to incorporate feedback from citizens who reported discomfort with the best economic solution (intense bluish light) – a decision to address the citizen’s preferences that also turned out to be the best for their health. This year, four years after the first adoption of the LED streetlight, the American scientific medical community agreed that the spectral quality of that bluish light, initially offered by LED suppliers, could have potential negative side-effects on health. The revised adopted solution significantly reduced light pollution and GHG emissions. 

The city of Bogotá is at the forefront of a movement to adopt low emission buses (hybrid and full electric) to improve air quality. This improvement may in turn provide significant health benefits to the population, including increased life expectancy. The city of Buenos Aires has been successfully reducing the amount of waste that goes to the landfill, while simultaneously reducing operational costs, reducing emissions and generating jobs. Solid waste can be seen as “nutrient,” as a resource, to another production cycle, basis of a new circular economy.

And even in areas where mayors do not have strong political power, such as food systems and individual consumption, through strengthened partnerships with diverse stakeholders, C40 cities are taking action and setting their vision toward this new urban paradigm shift. For instance, Milan, with the engagement and mobilization of 129 other global cities, is promoting sustainable food systems that are inclusive, resilient, safe and diverse. 

London, Paris and Portland are other great examples of being at the leading-edge of assessing consumer-based emissions – emissions that occur due to the consumption activities of residents – including all the emissions associated with the production of goods and services throughout their complete supply chain. Through this assessment, cities are able to identify opportunities for more efficient urban supply chains and are best positioned to engage citizens in furthering their sustainable behaviour. In London, for example, the household sector represents 75% of GHG emissions of the city. 

When validating that there is no trade-off between climate action and social and economic development, C40 cities demonstrate their ability to increase sustainability and quality of living to an increased number of urban dwellers, while implementing the New Urban Agenda. This action-oriented proposal to foster urban sustainable development in alignment with the SDGs (Sustainable Development Goals) and COP 21 Paris Agreement is a clear recognition of nation states on cities’ role to put the world on an inclusive, sustainable and safe pathway.

*Cristina Mendonça is C40 Cities Climate Leadership Group City Director in Rio de Janeiro.The C40 connects more than 85 of the world’s greatest cities, representing more than 650 million people and one quarter of the global economy. Created and led by cities, C40 is focused on tackling climate change and driving urban action that reduces greenhouse gas emissions and climate risks, while increasing the health, wellbeing and economic opportunities of urban citizens. To learn more about the work of C40 and our cities, please visit