London and Rio put cities at COP30 centre
24 June 2025
by Jonathan Andrews
Cities are set to play a central role at this year’s COP30 climate summit, with the launch of a new Local Leaders Forum in Rio de Janeiro and the expansion of London’s air quality monitoring programme, Breathe London.
Announced during London Climate Action Week, the COP30 Local Leaders Forum will bring together hundreds of mayors, governors and regional leaders in Rio this November. Co-hosted by the COP30 Presidency and Bloomberg Philanthropies, the three-day event aims to showcase local solutions and accelerate the delivery of global climate goals.
“Local leadership is essential to the success of global climate action,” said André Corrêa do Lago, COP30 President-Designate Ambassador. “The COP30 Local Leaders Forum will be a vital platform to highlight the role of cities and regions in delivering real, inclusive and lasting climate solutions.”
The Forum will precede the official COP30 negotiations in Belém and includes the C40 World Mayors Summit, the Global States and Regions Summit, and a political dialogue on multilevel collaboration. Outcomes are expected to focus on renewable energy, energy efficiency, urban resilience and climate finance.
Eduardo Paes, Mayor of Rio, who also leads Brazil’s National Front of Mayors, said the Forum would provide an opportunity for cities to shape the agenda.
“Cities and regions are on the frontlines of the climate crisis and are uniquely positioned to drive solutions,” he said. “This must be a COP of delivery.”
Breathe London expands with 146 new sensors
The announcement came alongside the launch of the next phase of the Breathe London programme, supported by £2.8 million in joint funding from the Mayor of London and Bloomberg Philanthropies. Led by Vodafone and a consortium of partners, the new phase will deliver 146 additional air quality sensors, including ten on and around Oxford Street, in support of London’s planned pedestrianisation.
“The first phase of my pioneering Breathe London programme has been a game-changer,” said Sadiq Khan, Mayor of London. “With the support of Bloomberg Philanthropies, we can take the global Breathe Cities initiative from strength to strength.”
Since its inception in 2021, Breathe London has deployed more than 400 sensors across the capital and supported 60 community groups with real-time air quality data. The model has informed the Breathe Cities network, now active in 14 cities including Nairobi, Brussels and Bangkok.
Michael Bloomberg, UN Special Envoy on Climate Ambition and Solutions, said the programme demonstrated how local data can inform public health decisions.
“This expansion of Breathe London will empower Londoners with critical information and help leaders create policies that will save lives,” he said.
London Climate Action Week also marked the 20th anniversary of the C40 Cities network, now comprising nearly 100 cities worldwide. Events included high-level discussions on green finance, electric vehicle infrastructure, and air quality, as well as the premiere of a film series profiling local climate initiatives.
The COP30 Local Leaders Forum will take place from 3 to 5 November in Rio de Janeiro. A delegation of city leaders will then travel to Belém to formally represent a unified subnational climate agenda during the main COP30 summit.
Image: 9parusnikov | Dreamstime.com
