By Zhimin Wu, Director, Forestry Division, FAO

Courbevoie, France, is a thriving business hub west of Paris. It’s also at the forefront of efforts to reduce food waste, bringing together local supermarkets, restaurants, and retailers. Instead of letting leftovers go to waste, the city redirects them to charities and those in need. It also educates children at school on the value of food and experiments with recycling, rather than simply disposing of, food waste.

As a member of the Green Cities Network of the Food and Agriculture Organization of the UN (FAO), Courbevoie is striving to demonstrate that being a city doesn’t mean putting sustainability on the back burner. Cities can become solutions to some of the most urgent challenges our century poses.    

By 2050, nearly seven billion people – almost 70% of the global population – will live in cities. This isn’t just a demographic shift. It is a massive transformation of the planet’s social, economic, and environmental fabric. Cities are becoming the default habitat of humans, often with detrimental consequences.

Today, on World Cities Day, we need to remember that we cannot afford to let urbanization run on autopilot.

Rapid urban growth can bring with it a familiar pattern. Green spaces give way to grey concrete. Natural ecosystems are paved over. Pollution and waste pile up. The cost of living climbs. At the same time, the climate crisis is battering cities with rising heat, worsening floods, and increasingly erratic weather.

While all this makes the intensifying urbanization trend worldwide sound like a recipe for disaster, it doesn’t have to be. Cities could – and should – do things differently.

That is the idea behind the Green Cities Initiative, launched by FAO in 2020. The aim is to help cities around the world rethink how they feed people, how they manage land and water, and how they support healthier, more resilient urban communities.

Many like Courbevoie are joining the FAO Green Cities Network to share experiences and innovations, tap into FAO’s technical support and seek financial assistance. Increasingly, cities around the world are ready to expand green spaces, plan sustainable housing and transport, participate in the production of healthy food, use water resources better, and link all the above to their economies.

The goal of the Green Cities Initiative is to generate tangible improvements in the health and well-being of people and their environments in 1,000 cities worldwide by 2030. This also contributes to SDG 11 (sustainable cities and communities).

But what exactly makes a city “green”? A green city is one that strikes a genuine balance between people and nature. In practical terms, that means three things.

First, a green city places human health and well-being at the heart of urban development. That means agrifood systems are designed to provide nutritious, locally produced, affordable food to city dwellers. Daily contact with nature is part of urban life – in parks, gardens, and tree-lined streets and along green corridors. Green public spaces are safe, welcoming and accessible to all, and are co-designed with citizens to ensure the equitable distribution of benefits.

Second, a green city protects, restores, and manages ecosystems as essential urban infrastructure. Urban nature is treated as a life support system. Trees, wetlands, soils, and waterways are restored to regulate temperature, capture stormwater, and filter pollutants. Urban land is planned and managed to simultaneously deliver benefits such as food, shade, recreation, and habitat and to connect with peri-urban and rural landscapes. Climate resilience is built into planning to reduce exposure to floods, heatwaves, and droughts.

Third, it builds economies that recycle resources, reduce waste, and support sustainable jobs. Organic waste is recovered from food, transformed into animal feed, and converted into biogas and agricultural inputs. Water is harvested and reused, and locally available renewable materials, such as sustainably sourced wood, are employed for construction and infrastructure development. Investments in capacity development and innovation support local enterprises, create green jobs, and diversify urban economies.

Crucially, the impacts of a truly green city extend beyond its borders: it works with peri-urban and rural spaces surrounding it. Whether through agriculture, sustainable forestry, or ecosystem protection, a green city is planned and managed in direct connection with the rural landscapes that sustain it.

And this isn’t just empty talk. Many cities are already showing that it is possible to redesign urban life to work better for people and the planet. Kigali, Rwanda, is engaged in tree planting that spans the entire city. Colombo, Sri Lanka, is strengthening urban agriculture by putting up greenhouses and installing garden equipment. Ulaanbaatar, Mongolia, is working to improve existing green spaces, not least by planting native tree species and protecting water sources.

At the First International Green Cities Conference in Rome this month, dozens of mayors, government ministers, and urban experts from around the world gathered to share more real world solutions – from vertical farms in Latin America and composting systems in Europe to greenbelts in Africa, where booming urban populations and the worsening impacts of climate change make this work especially urgent. Through FAO’s Green Cities Initiative in Action for Africa, and with support from the Italian government, ten cities in Algeria, Côte d’Ivoire, Kenya, Mozambique, and Uganda are now developing detailed investment plans to restore ecosystems, support urban farmers, improve food and water systems, and make sure benefits reach vulnerable communities.

Only strong leadership, investment, and public support can enable the transformation of our cities. And many, contrary to conventional wisdom, are already on their way to becoming powerful engines of sustainability.