Global Climate Leadership in Focus

London Mayor Sadiq Khan has publicly urged the UK’s Labour government to deliver an “authentic” budget that significantly boosts green investment, challenging the administration to confidently defend its climate policies against claims they fuel the cost of living crisis. His remarks were made on Sunday, November 2, 2025, ahead of the C40 World Mayors Summit in Rio de Janeiro, Brazil, which begins today, Monday, November 3, 2025.

Khan, who serves as the co-chair of the C40 Cities network, a global coalition of nearly 100 mayors dedicated to confronting the climate crisis, emphasised the need for political authenticity. “The public can smell somebody who’s inauthentic. And I think you should be authentic. People respect somebody if you’re authentic,” he stated, referencing his own experience implementing London's Ultra Low Emission Zone (ULEZ) to tackle air pollution.

The Kenyan Connection: Nairobi's Role in C40

Khan's call for decisive action in a leading global economy resonates directly with the challenges and ambitions of Nairobi. The Kenyan capital has been a member of the C40 network since 2014 and plays a significant role in representing the continent's urban climate agenda. In June 2023, Nairobi Governor Sakaja Johnson was elected as a Vice Chair of the C40 Steering Committee, tasked with representing the 13 C40 cities in Africa and championing their climate priorities on the world stage.

The C40 network provides cities like Nairobi with a platform for peer-to-peer knowledge exchange and technical assistance to accelerate climate projects. This includes initiatives focused on sustainable mobility, waste management, and air quality—issues pertinent to both London and Nairobi. Khan’s advocacy for green investment in the UK is crucial, as financial commitments from developed nations are vital for unlocking capital for climate projects in the Global South through mechanisms like the C40 Cities Finance Facility (CFF).

Financing the Green Transition

The London mayor specifically called on the UK Treasury to be more supportive of the government's ambitious climate targets. In November 2024, the UK government announced a new Nationally Determined Contribution (NDC) under the Paris Agreement, pledging to cut greenhouse gas emissions by at least 81% by 2035 compared to 1990 levels. Khan's intervention highlights internal debates within the UK's ruling Labour party over the scale and timing of its proposed £28 billion annual green investment plan, a figure he acknowledged might not be achievable until later in the government's first term.

This debate mirrors the financial hurdles faced by Kenya. While Kenya has emerged as a continental leader in climate action, aiming for net-zero emissions by 2050, it faces a significant funding gap. According to its NDC financing strategy, the country requires approximately $40 billion in investment over the next decade to meet its climate goals. Challenges in securing this capital include complex regulatory requirements, limited access to diverse financial instruments beyond grants, and a perceived high risk among private investors.

Implications for East Africa

The decisions made in global financial centres like London have a direct impact on the viability of green projects across East Africa. A strong commitment to green investment from the UK government can bolster international climate finance flows, build investor confidence, and set a powerful precedent for other developed nations ahead of the pivotal COP30 climate negotiations in Brazil.

For Nairobi and other regional cities, Khan’s message is a reminder of the importance of bold, clearly communicated policies to drive sustainable urban development. As Governor Johnson works to implement Nairobi's climate action plan, the success of such initiatives will depend not only on local leadership but also on a global financial architecture that is genuinely committed to supporting a just and equitable green transition. The outcomes of the C40 summit in Rio this week will be closely watched for further commitments on mobilising the resources needed to turn urban climate ambitions into reality.