C40 Cities Climate Leadership Group

The C40 Cities Climate Leadership Group (C40) is a network of the world’s megacities taking action to reduce greenhouse gas emissions. C40 harnesses the assets of member cities to address climate risks and impacts locally and globally.

C40 is composed of 83 member cities around the world. On November 26, the former C40 Chairman, the 108th Mayor of New York City, Michael R. Bloomberg, was succeeded by the Mayor of Rio de Janeiro, Eduardo Paes. Mayor Bloomberg served as the elected leader of the organization from 2010 – 2013, he will stay on as the President of the C40 Board of Directors. Along with the Chairman, a rotating steering committee of C40 mayors provides strategic direction and governance. Current steering committee members include: Tokyo, Hong Kong, Johannesburg, Jakarta, London, Seoul, Los Angeles, Copenhagen, Milan, Boston, Mexico City, Amman and Rio de Janeiro. With a focus on collaboration among member cities to excel climate actions[clarification needed], C40 has established eighteen networks across seven initiative areas with a to support collaborative problem solving, promote the exchange of programs and policies developed by cities, and facilitate targeted peer-to-peer dialogue among city staff.

Through these efforts, C40 aims to demonstrate that cities are significantly reducing greenhouse gas emissions and hopes to provide proven models that other cities and national governments can adopt. In the words of C40 President Michael Bloomberg: „While international negotiations continue to make incremental progress, C40 Cities are forging ahead. Collectively they have taken more than 5,000 actions to tackle climate change, and the will to do more is stronger than ever. As innovators and practitioners, our cities are at the forefront of this issue – arguably the greatest challenge of our time.“

The organization started in October 2005 when the former mayor of London, Ken Livingstone, convened representatives from 18 megacities to pursue action on reducing greenhouse gas emissions. The meeting resulted in an agreement to reduce greenhouse gas emissions by taking action on a number of points, most notably procurement policies and alliances to accelerate the uptake of climate-friendly technologies. This agreement began what later became known as the C40 Climate Leadership Group.

In 2006, Mayor Livingstone and the Clinton Climate Initiative (CCI)—led by the efforts of former U.S. President Bill Clinton—, bringing the number of cities in the network to 40 and helping to deliver projects and project management for participating cities to further enhance emissions reductions efforts.

Serving as C40’s first Chairman, Mayor Livingstone established the C40 Secretariat in London, set up the C40 Steering Committee, and initiated the use of C40 workshops to exchange best practices amongst participating cities. In 2008, former Mayor of Toronto David Miller took over as C40 Chairman. Highlights of his tenure included the Copenhagen Climate Summit for Mayors and the C40 Cities Mayors Summit in Seoul, both in 2009, as well as the launch of practical action initiatives for cities, such as the C40-CCI Climate Positive Development Program and the Carbon Finance Capacity Building program.

The tenure of current C40 Chairman, Rio de Janeiro Mayor Eduardo Paes, began in December 2013, following the 2010-2013 Chairmanship of the Mayor of New York City Michael Bloomberg. Key milestones in 2011 include the full integration of the CCI Cities Program into the C40, the C40 Cities Mayors Summit in Sao Paulo, the release of two reports developed in collaboration with the Carbon Disclosure Project (CDP) and Arup Group Limited, and the announcement of two new partnerships with the World Bank and Local Governments for Sustainability (ICLEI). Key milestones in 2012 include the first-ever cataloging of mayoral/municipal authority over various city assets, the release of a draft edition of the Global Protocol for Community-scale Greenhouse Gas Emissions to harmonize emissions measurement and reporting across cities, strengthening C40’s partnership with the World Bank to better enable cities in developing parts of the world to drive local climate action, and C40’s announcement at the global Rio+20 climate summit that C40 Cities’ existing actions will reduce global annual GHG emissions by 248 million tonnes in 2020, with the potential to reduce over 1 billion tonnes by 2030. Under Mayor Bloomberg’s leadership, C40 has grown to include 63 cities.

In 2014 C40 Chairman, Rio de Janeiro Mayor Eduardo Paes oversaw the addition of seven new member cities, several groundbreaking research reports, successful international events, and thriving global partnerships – all of which are helping cities make real contributions to the reduction of global greenhouse gas emissions and climate risks.

In February, at the C40 Mayoral Summit membership was expanded to include three new African cities: Cape Town, Dar es Salaam and Nairobi. Later in the year, we also welcomed Boston, Chinese cities Shenzhen and Wuhan, and most recently Tshwane in South Africa, bringing their total membership to 70 megacities.

To better support and advance C40 Cities goals, three new networks were launched, including , and .

2014 also saw the release of substantial Research publications, including the , the second installment of C40’s seminal research series that catalogues and analyzes climate action in C40 cities; The Compact of Mayors – the largest cooperative effort among cities to accelerate local climate action. New research by the parties to the Compact, in partnership with Arup, showed that 228 cities worldwide already have plans in place to reduce their greenhouse gas emissions; further showed that cities have a huge potential to contribute to additional reductions beyond what nations have already counted; Finally in December, C40 and partners formally released the , the first global standard for cities to measure and report their greenhouse gas emissions, allowing cities to track their own progress, as well as contribute accurate data to national emissions inventories and goals.

In March 2015 C40 further expanded their membership to 75 megacities, bringing Amman, Jaipur, Durban, Quito and Salvador on board.

In August 2015 C40 extended a warm welcome to newest member cities Bengaluru, Dubai, and Quezon City, which together represent more than 22 million urban citizens.

During the U.S.-China Climate Leaders Summit in Los Angeles in September 2015, the C40 Cities Climate Leadership Group announced the addition of Chinese megacities Guangzhou and Nanjing to its global network of cities tackling climate change and driving urban action that reduces both greenhouse gas emissions and climate risks, whilst increasing well-being for urban citizens.

Then in November 2015 C40 welcomed Kolkata to join other C40 cities Bengaluru, Delhi NCT, Jaipur, and Bombay as C40’s fifth Indian member city.

December 2015 was a very exciting month for C40. Auckland joined C40 as the first C40 member from New Zealand growing C40 membership to 83 megacities around the world.

In addition, COP21 was run in Paris, France from Nov 20 – Dec 11 and was a pivotal week for the global effort to stave off climate change. But it was also a critical week for cities, who firmly established their roles as key factors for successfully implementing the historic deal.

C40 has 83 participating member cities across seven geographic regions.


Innovator cities:

Observer cities:

While C40 originally targeted megacities for their greater capacity to address climate change, C40 now offers three types of membership categories to reflect the diversity of cities taking action to address climate change. The categories consider such characteristics as population size, economic output, environmental leadership, and the length of a city’s membership.

1. Megacities

2. Innovator Cities

3. Observer Cities

Megacities make up the core of C40’s membership, with the majority of cities currently in this category across developed and developing regions. As such, megacities retain sole access to C40 leadership and governance opportunities, such as serving as C40 Chair, as members of the C40 Steering Committee and the C40 Board.

A C40 Network is an active working group of C40 Cities with commonly identified opportunities, interests or priorities. Networks are supported by C40 staff to facilitate knowledge transfer and peer-to-peer exchange, as well as to provide direct support to cities developing local policies, programmes or projects in the network’s area of focus; this direct support is provided either by C40’s own technical staff or through managed partnerships. Networks are designed to be dynamic and nimble, responding to the changing needs and priorities of participating cities. C40 has established a data-driven approach to identify and launch networks, ensuring that resources are strategically deployed by mapping city priorities to focus areas with the greatest potential GHG and climate risk impact.

C40’s efforts are focused into seven overarching initiative areas and associated networks that allow for support and collaboration among and between C40 cities.

C40 Research, Measurement and Planning leverages their unprecedented database of city actions, extensive network of partnerships, and unique organisational insight to demonstrate the power of cities to address climate change. C40’s Research analyses key trends, identify opportunities for further action across the global C40 network, and help prioritize C40 initiative areas with the greatest potential for action and impact. C40’s research agenda is committed to turning data and planning into implementation. Producing tools, standards and frameworks Research, Measurement and Planning supports cities to implement the most impactful mitigation and adaptation actions and measure and manage their effectiveness.