City leaders have called for an accelerated shift away from fossil fuels, positioning renewable energy as central to energy security, affordability and economic stability. The message was delivered as national governments and urban representatives gathered in Santa Marta, Colombia, for the First Conference on Transitioning Away from Fossil Fuels, co-hosted by Colombia and the Netherlands.

The conference brings together national and subnational actors at a time of continued volatility in global energy markets. Against this backdrop, cities are presenting renewable energy as a practical route to reducing exposure to price shocks and supply disruptions linked to fossil fuel dependence.

Earlier in the month, more than 25 cities joined Colombia and the Netherlands in a virtual dialogue convened by C40 and ICLEI. The discussion aimed to ensure that outcomes from the conference reflect urban priorities and demonstrate how energy transition policies are being applied at the local level.

Energy price instability has been a central concern. Cities point to the immediate effect of fluctuations in oil and gas markets on households, businesses and public finances. Renewable electricity, particularly solar and wind, is now cited as a lower-cost alternative, with new capacity reported to cost at least 50% less than new fossil fuel generation.

Data presented alongside the conference indicates that 92% of countries have renewable energy potential exceeding ten times their current demand. This suggests a significant gap between existing deployment and available capacity.

Urban areas are identified as critical to progress. Cities account for around 75% of global energy-related emissions, placing them at the centre of both the challenge and the response. Across C40 cities, per capita emissions have fallen below pre-pandemic levels, marking four consecutive years of decline.

Examples of city-led initiatives were presented as evidence of progress. London’s clean air zone, Melbourne’s renewable energy purchasing model supplying all municipal operations, and Curitiba’s solar procurement programme, which is reducing energy bills in public buildings by 30%, were cited among current measures.

Other examples include Johannesburg’s US$140 million green bond, which has financed energy and efficiency projects, and Warsaw’s support schemes for low-income households transitioning to clean heating. In Bogotá, a designated low-emission zone has been introduced in a heavily polluted area, benefiting nearly 40,000 residents through improved air quality and reduced emissions.

Workforce development is emerging as a key consideration in the transition. Cities report labour shortages across sectors including transport, construction and waste management. Analysis from C40 covering 25 cities suggests that up to 6 million additional workers may be required by 2040.

In response, local governments are working with labour groups and industry to retrain workers from declining sectors into roles such as solar installation, electric vehicle maintenance and green construction. These efforts are intended to support employment while aligning workforce capacity with the needs of the energy transition.

The actions outlined form part of a broader commitment by C40 mayors to halve fossil fuel use in cities by 2030. This target aligns with the global goal agreed at COP28 to triple renewable energy capacity by the end of the decade.

Health and economic benefits were also highlighted. The transition away from fossil fuels is associated with the potential to prevent more than 776,000 premature deaths by 2050, alongside reducing health-related economic losses. At the same time, more than 21 million green jobs already exist across C40 cities, with projections suggesting that four in ten jobs could be classified as green by 2040.

Despite progress, cities emphasised the need for stronger collaboration with national governments. Key priorities include integrating urban action into national energy and climate plans, expanding access to finance, and enabling decentralised energy systems.

Investment mechanisms such as municipal green bonds and direct renewable energy purchasing agreements were identified as areas where policy support could unlock further progress. Grid modernisation and electrification were also cited as necessary to ensure clean energy is accessible and affordable.

Irene Vélez Torres, Minister of Environment and Sustainable Development of Colombia, declared:

“Colombia has been clear: the transition away from fossil fuels is not only necessary, it is an opportunity to build a more just and resilient future. But this transformation cannot be achieved by national governments alone. Cities and regions are essential to this effort. They are where people live, where inequalities are felt most deeply, and where the impacts of climate change are already being experienced every day. That is why we must work together to accelerate this transition in a way that delivers a better future for those who matter most: people. This is about moving forward. All together.”

Stientje van Veldhoven, Minister of Climate Policy and Green Growth, Kingdom of the Netherlands, declared:

“The Netherlands is committed to accelerating the transition away from fossil fuels as a practical pathway to secure clean, reliable and affordable energy for our societies. But this transformation cannot be delivered by national governments alone. Cities are essential partners: they are where innovation happens, where solutions are implemented, and where people experience the benefits of this transition in their daily lives. That is why we must work together to turn ambition into action, by supporting cities, unlocking investment, and scaling the solutions that are already working. This is how we build stronger, more resilient economies and deliver a better future for everyone.”

City leaders also outlined local perspectives on implementation. Geordin Hill-Lewis, Mayor of Cape Town, South Africa, declared: “In Cape Town, we are working to secure a more reliable and affordable energy future by diversifying our energy supply and investing in renewables. By enabling independent power production and reducing reliance on fossil fuels over time, we are strengthening energy security while creating new economic opportunities. This transition is essential for building a more resilient city that can better serve its residents.”

Pabel Muñoz, Mayor of Quito, Ecuador, declared:

“Quito is moving decisively toward clean energy because cleaner air, lower costs, and a healthier city for our people are unquestionable benefits we all should pursue. By investing in sustainable transport and modern energy systems, we are not only reducing our reliance on fossil fuels, we are building a more just and resilient future. This transition is not a political view or an option, it is essential to our communities future. And we must urgently act.”

H.E. Hon. Sakaja Arthur Johnson, Governor of Nairobi, Kenya, declared:

“In Nairobi, we are investing in cleaner public transport and expanding access to reliable energy to support a growing city. This transition is creating jobs, improving mobility, and delivering more affordable solutions for our communities. Moving towards more sustainable energy sources is about building a city today that works better for future generations.”

Haris Doukas, Mayor of Athens, Greece, declared:

“In Athens, we are accelerating the shift to clean energy by investing in energy-efficient buildings, expanding sustainable transport, and reducing our reliance on fossil fuels across the city. Through initiatives like our Energy Poverty Office, we are also ensuring that vulnerable households can access affordable, clean energy solutions. These actions are helping us lower costs, improve air quality, and strengthen resilience. The transition away from fossil fuels is a global challenge, which is why we also support efforts such as the Fossil Fuel Treaty. This transition is not only necessary, it is an opportunity to build a more liveable, secure and fair future for all our communities.”

Caterina Sarfatti, C40’s Managing Director for Political Strategy & Advocacy, declared:

“Across the world, cities are showing that transitioning away from fossil fuels is not only possible, but it is already happening and delivering real benefits for people. At a time when households are facing rising energy bills, supply shocks, and the growing impacts of climate change, our toxic dependence on fossil fuels is exposing communities to instability and risk. From lower energy costs to cleaner air and more resilient communities, this transition is improving lives today while securing our future. And cities are where this transition moves from words to facts. Mayors are electrifying transport, scaling clean energy, training the workforce and making homes more efficient and affordable, proving that we can grow stronger economies while reducing our reliance on volatile fossil fuel markets. This is an opportunity to build healthier, more affordable, and safer communities. And cities are ready to lead.”

C40 is a network of nearly 100 mayors working to address the climate crisis through urban action. The organisation supports cities in reducing emissions, increasing resilience and advancing equitable development in line with the Paris Agreement.