From Johannesburg to the world, here’s how cities drove the U20 agenda.
The Urban 20 (U20) Summit concluded on a powerful note on 14 September 2025 in Johannesburg. Co-chaired by the cities of Johannesburg and Tshwane, the event made history as the first U20 ever held in Africa. U20 brings together mayors from cities around the world to ensure that urban priorities are heard by G20 leaders. This year, leaders from more than 30 cities—including Ahmedabad, Freetown, Accra, Rotterdam, and Amsterdam—gathered in Johannesburg to champion multilateralism and make sure city voices are reflected in G20 discussions and COP30 negotiations, alongside the upcoming C40 World Mayors Summit in Rio.
A platform for renewed multilateralism
With a key focus on collaboration, discussions centred on how cities and countries can work together as equal partners to tackle the world’s toughest challenges. African cities took centre stage, amplifying the regional voices, sharing fresh ideas, and showing real progress on building greener, fairer, and more resilient communities.
The summit was co-chaired by Johannesburg and Tshwane, and convened by C40 Cities and United Cities and Local Governments (UCLG). It built on the momentum from the U20 Sherpa Meeting in Tshwane in June, where city leaders from G20 countries developed shared priorities to present to the G20 later this year. C40 Cities was represented by C40 Co-Chair Mayor of Freetown Yvonne Aki-Sawyerr OBE, who sent a powerful message on the need for finance for an urban just transition, and the importance of taking the voice of cities to COP30.
Planting seeds of hope
Before the Summit kicked off, leaders joined a symbolic tree-planting ceremony that carried powerful meaning. The event echoed South African President Cyril Ramaphosa’s ambitious plan to plant 10 million trees over the next five years—a national commitment to tackling climate breakdown, biodiversity loss, and environmental degradation.
This was not just symbolic. In Johannesburg alone, 10,000 trees were planted in September, greening neighbourhoods across the city. Saplings from countries represented at the Summit were planted side by side, reminding leaders that global collaboration must take root locally.
A crucial role for cities
The Summit formally opened on Friday, 12 September, with a call for cities to be recognised not just as local implementers, but as global political actors. Executive Mayor of Johannesburg Dada Morero set the tone: “Cities are not junior partners but global political actors in their own right. The wellbeing of every city is bound by the wellbeing of all.”
Jazmin Burgess, C40’s Inclusive Climate Action Director, stressed that as the closest level of government to their communities, cities must be recognised and empowered to deliver the just transition locally, creating good green jobs and ensuring climate action meets the social and economic needs of residents. The ask to recognise and support cities as just transition implementers was put forward to the G20 Environment Working group with a policy brief launched at the Summit.
Megan Euston Brown, Director of Sustainable Energy Africa, stressed the need for bold climate action plans: “They need to be the most radical plans in cities and have to challenge the status quo.” Karl Pfeffer of the International Labour Organization (ILO) emphasised that a just transition should be about ensuring the transition to greener, cleaner cities is done in a way where no one is left behind and that there are “no losers in the transition”.
Unlocking climate finance
Financing was a recurring theme. Charity Warayayi, Acting Head of Finance at the City of Johannesburg, reminded participants: “It’s about turning pledges into running water, moving buses, and safer cities. Cities are ready to work with national governments, DFIs, and other partners.”
“Local and regional governments, she emphasised, are not passive beneficiaries but partners and co-owners of the transition. They are the bridge to communities, making just transitions real through co-design, co-delivery, and shared responsibilities.”
Closing with a call to action
The Summit closed with Executive Mayor of Johannesburg Dada Morero and Executive Mayor of Tshwane Dr Nasiphi Moya handing over the U20 Communiqué—endorsed by 37 cities and counting—to South Africa’s Minister of Cooperative Governance and Traditional Affairs (COGTA) and the G20 Social Summit lead.
In their Communiqué, mayors called on G20 governments to:
- Recognise cities as essential partners in global decision-making
- Unlock direct access to finance for urban priorities
- Collaborate on climate action and a just transition
- Support inclusive economic development
- Expand affordable housing
- Ensure a human rights-based approach to migration
- Harness digital innovation responsibly
South Africa commits to taking the voice of cities to G20
National government officials—including Parks Tau, Minister of Trade, Industry and Competition, and Thembisile Phumelele Simelane, Minister of Human Settlements—were present throughout the summit, listening directly to mayors’ priorities and engaging on urgent issues such as the housing crisis, climate breakdown, urban climate finance, multi-level governance, and the road to COP30.
Minister Parks Tau received the Communiqué, calling it a reflection of South Africa’s local priorities and committed that South Africa would lead the advocacy to the G20 for these to be taken forward and implemented.
Executive Mayor Moya described the Communiqué as “a blueprint for action,” underlining the need for genuine multilevel governance, stronger cooperation, and financial empowerment for cities. “From Johannesburg to COP30 in Belém, Tshwane will be a relentless advocate. We are on the front lines, ready to turn these resolutions into real progress for our people.”
Beyond Johannesburg: Carrying the momentum forward
At the closing press conference, C40 Co-Chair Mayor of Freetown Yvonne Aki-Sawyerr OBE reflected: “These three days have been monumental. And what matters most is that this hasn’t been a talking shop. Every single one of the priorities in the U20 Communiqué speaks to the specific issues that our residents face. The Communiqué is reinforcing our positions, allowing central governments to incorporate more clearly the work that we are doing.”
She emphasised that C40 cities will amplify the Communiqué globally—at the leadership forum in Rio, at COP, at UNGA, and beyond.
Shruti Narayan, C40’s Managing Director of Regions and Mayoral Engagement, reinforced that mayors and partners will be watching for urban priorities to be reflected in G20 outcomes. With the US hosting the G20 next year, momentum from U20 Johannesburg will carry forward, strengthened by dedicated U20 American cities.
A shared achievement
The U20 Johannesburg Summit was a milestone not only for African cities but for global urban leadership. It demonstrated that cities are crucial in addressing the climate crisis, promoting justice, and creating inclusive, sustainable futures.
A heartfelt thank you went to the South African Local Government Association (SALGA), UN-Habitat, national government representatives, the Presidential Climate Commission (PCC), all partners who made this historic summit possible, and the co-conveners C40 Cities and UCLG.