What Is The C40 Cities Group & What Has It Achieved?

by Julia Gaus


Cities are home to more than half of the world’s population, generate over 80% of global GDP, and are responsible for more than 70% of global greenhouse gas emissions; tendency: increasing [1]. Therefore cities play a key role in global climate action which goes beyond implementing the policies mandated by national governments.

In order to deliver the ambitious and urgent action required to fight the climate crisis and limit global warming to 1.5°C while also building resilient and sustainable communities, cities worldwide are collaborating within various networks. One of the most well known is C40 CITIES.

The name stems from the number of cities that became founding members back in 2006 when the then London mayor Ken Livingstone’s C20 initiative gained the Clinton Climate Initiative as an implementing partner and invited more cities to join the new network [2]. Since then the organisation has grown to currently (November 2021) 97 of the world’s leading cities that collectively account for 27% of the global economy and more than 800 million citizens [3]. From its origin as a network of megacities the group has expanded to also offer membership to innovator and observer cities thus counting with a diverse membership [4]. 

Achievements of C40 CITIES group

According to its 2020 annual report, C40’s stated mission is: “to halve the collective carbon emissions of our member cities within a decade, while improving resilience and equity and creating the conditions for everyone, everywhere to thrive” [3].

Its central instrument for achieving this mission are its 16 networks on various mitigation, adaptation, and sustainability topics crucial to member cities and harbouring the greatest climate impact potential [5]. These peer-to-peer networks serve as a platform through which cities can showcase, improve, replicate, and accelerate climate action. Networks are designed to connect cities around the world, inspire, advise, and influence national and international policy agendas and have been reported in 70% of C40 cities to lead to the implementation of faster or better climate actions [3]. One example: 88 C40 cities have committed themselves to climate action that is in line with achieving the 1.5°C goal [3]. 

Over the 15 years of its existence C40 has added other services for its member cities. Programmes on a diverse range of topics have been developed to enhance the effectiveness of C40 networks. To name but a few, Women4Climate, C40 City Diplomacy or the City Intelligenceprogramme [6]. In addition, the C40 Cities Finance Facility (CFF) is a strong mobilisation mechanism of climate finance for projects in cities of the Global South; by 2020 it has mobilised US$650 million [3].

A last role of C40 is as an agenda setter and driver of climate action. It does so through its own research activities, leveraging its unprecedented database. Additionally, C40 actively engages in international UNFCCC climate negotiations as a non-Party stakeholder, having (for example) inspired 1000 cities to sign on to its “Cities Race to Zero” pledge in the run-up to COP26 [3].


The central idea behind C40 CITIES is that climate action at the national level is too weak and that it takes local action in combination with national policy to confront the climate crisis [7]. While C40 has become a key actor in international climate action, space for improvement remains. Before the Fridays For Future movement, local action was mainly determined at the level of the city government with individual citizens not being seen as active stakeholders [8]. Enforcing links to the urban population and involving them actively in climate action thus offers great opportunities to further enhance local action. 

C40 has been found to pivot towards conventional economic solutions that aim to create a sustainable future without endangering economic growth [8]. One example of this is cities building a green image with the aim of attracting private investment and creating new markets or climate action being justified on security or economic grounds [8]. This reformist approach might not be enough to confront the climate crisis and should be replaced by a more transformational one. 


[1] Urban Development, The World Bank, https://www.worldbank.org/en/topic/urbandevelopment/overview#1, accessed on 28/10/21 
[2] About C40, C40 CITIES, https://www.c40.org/about-c40/, accessed on 28/10/21 
[3] C40 Annual Report 2020, 2021, C40 CITIES, https://c40-production-images.s3.amazonaws.com/other_uploads/images/2827_C40_Annual_Report_2020_vMay2021_lightfile.original.pdf?1622806882, p.4 
[4] The Power of C40 Cities, C40 CITIES, https://www.c40.org/cities, accessed on 28/10/21
[5] Networks, C40 CITIES, https://www.c40.org/networks/, accessed on 26/10/21
[6] Programmes, C40 CITIES, https://www.c40.org/programmes, accessed on 26/10/21
[7] Kathryn Davidson & Brendan Gleeson, 2015, Interrogating Urban Climate Leadership: Toward a Political Ecology of the C40 Network, Global Environmental Politics, 15(4), doi:10.1162/GLEP_a_00321
[8] Milja Heikkinen, Tuomas Ylä-Anttila & Sirkku Juhola, 2019, Incremental, reformistic or transformational: what kind of change do C40 cities advocate to deal with climate change?, Journal of Environmental Policy & Planning, 21, doi.org/10.1080/1523908X.2018.1473151
Categories Urban Policies

Tell us what you think!

This site uses Akismet to reduce spam. Learn how your comment data is processed.