C40 Cities Climate Leadership Group is a group of 96 cities that represents one twelfth of the world's population and one quarter of the global economy.
Created and led by cities, C40 is focused on fighting the climate crisis and driving urban action that reduces
greenhouse gas emissions
Greenhouse gas (GHG) emissions from human activities intensify the greenhouse effect. This contributes to climate change. Carbon dioxide (), from burning fossil fuels such as coal, petroleum, oil, and natural gas, is the main cause of climate chan ...
and
climate risks, while increasing the health, wellbeing and economic opportunities of urban residents.
From 2023, Mayor of
London
London is the Capital city, capital and List of urban areas in the United Kingdom, largest city of both England and the United Kingdom, with a population of in . London metropolitan area, Its wider metropolitan area is the largest in Wester ...
,
Sadiq Khan
Sir Sadiq Aman Khan (, ; born 8 October 1970) is a British politician serving as Mayor of London since 2016. He was previously Member of Parliament (United Kingdom), Member of Parliament (MP) for Tooting (UK Parliament constituency), Tooting ...
and Mayor of
Freetown
Freetown () is the Capital city, capital and largest city of Sierra Leone. It is a major port city on the Atlantic Ocean and is located in the Western Area of the country. Freetown is Sierra Leone's major urban, economic, financial, cultural, e ...
,
Yvonne Aki-Sawyerr serve as C40's Co-Chair, former mayor of
New York City
New York, often called New York City (NYC), is the most populous city in the United States, located at the southern tip of New York State on one of the world's largest natural harbors. The city comprises five boroughs, each coextensive w ...
Michael Bloomberg
Michael Rubens Bloomberg (born February 14, 1942) is an American businessman and politician. He is the majority owner and co-founder of Bloomberg L.P., and was its CEO from 1981 to 2001 and again from 2014 to 2023. He served as the 108th mayo ...
as Board President, and Mark Watts as Executive Director. All four work closely with the 13-member steering committee, the Board of Directors and professional staff. The rotating steering committee of C40 mayors provides strategic direction and governance.
Steering committee members include: London, Freetown, Phoenix, Medellin, Copenhagen, Paris, Dhaka North, Nairobi, Tokyo, Rio de Janeiro, Montreal, Milan, Seoul, Oslo and Hong Kong.
Working across multiple sectors and initiative areas, C40 convenes networks
of cities providing a suite of services in support of their efforts, including: direct technical assistance; facilitation of peer-to-peer exchange; and research, knowledge management & communications. C40 is also positioning cities as a leading force for climate action around the world, defining and amplifying their call to national governments for greater support and autonomy in creating a sustainable future.
History
C40 started in October 2005 when
London
London is the Capital city, capital and List of urban areas in the United Kingdom, largest city of both England and the United Kingdom, with a population of in . London metropolitan area, Its wider metropolitan area is the largest in Wester ...
Mayor
Ken Livingstone
Kenneth Robert Livingstone (born 17 June 1945) is an English former politician who served as the Leader of the Greater London Council (GLC) from 1981 until the council was Local Government Act 1985, abolished in 1986, and as Mayor of Londo ...
convened representatives from 18 megacities to forge an agreement on cooperatively reducing climate pollution and created the 'C20'.
In 2006, Mayor Livingstone and the
Clinton Climate Initiative (CCI)—led by the efforts of former U.S. President
Bill Clinton
William Jefferson Clinton (né Blythe III; born August 19, 1946) is an American politician and lawyer who was the 42nd president of the United States from 1993 to 2001. A member of the Democratic Party (United States), Democratic Party, ...
—combined to strengthen both organizations, 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 chair, 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
Toronto ( , locally pronounced or ) is the List of the largest municipalities in Canada by population, most populous city in Canada. It is the capital city of the Provinces and territories of Canada, Canadian province of Ontario. With a p ...
David Miller took over as C40 chair. 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
Climate Positive Development Program and the Carbon Finance Capacity Building program.
Three-term
Mayor of New York City
The mayor of New York City, officially mayor of the City of New York, is head of the executive branch of the government of New York City and the chief executive of New York City. The Mayoralty in the United States, mayor's office administers all ...
Michael Bloomberg
Michael Rubens Bloomberg (born February 14, 1942) is an American businessman and politician. He is the majority owner and co-founder of Bloomberg L.P., and was its CEO from 1981 to 2001 and again from 2014 to 2023. He served as the 108th mayo ...
served as chair from 2010 to 2013. During his three-year tenure, Mayor Bloomberg demonstrated unwavering commitment to building a professional organization and establishing measurable and uniform benchmarks for success, as well as expanding knowledge-sharing between cities and partner organizations with similar priorities. Key milestones during his chairmanship include the full integration of the CCI Cities Program into the C40, and the C40 Mayors Summits in
São Paulo
São Paulo (; ; Portuguese for 'Paul the Apostle, Saint Paul') is the capital of the São Paulo (state), state of São Paulo, as well as the List of cities in Brazil by population, most populous city in Brazil, the List of largest cities in the ...
and
Johannesburg
Johannesburg ( , , ; Zulu language, Zulu and Xhosa language, Xhosa: eGoli ) (colloquially known as Jozi, Joburg, Jo'burg or "The City of Gold") is the most populous city in South Africa. With 5,538,596 people in the City of Johannesburg alon ...
. Under Mayor Bloomberg's leadership, C40 grew to include 63 cities.
In December 2013 former mayor of Rio de Janeiro
Eduardo Paes became Chair of C40. During his tenure Mayor Paes oversaw the addition of more than 20 new member cities (particularly those in the Global South) 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. He also helped launch the
Compact of Mayors (now the Global Covenant of Mayors for Climate & Energy), put in place the C40 Cities Finance Facility, and oversaw the opening of a permanent C40 office in Rio de Janeiro, at the Museum of Tomorrow.
In 2015, as C40 marked its 10th anniversary, cities were crucial voices in shaping and advocating for a strong
Paris Agreement
The Paris Agreement (also called the Paris Accords or Paris Climate Accords) is an international treaty on climate change that was signed in 2016. The treaty covers climate change mitigation, adaptation, and finance. The Paris Agreement was ...
—just as city leaders will be crucial in delivering on its ambition going forward. More than 1,000 mayors, local representatives, and community leaders from around the world took part in the Climate Summit for Local Leaders, hosted by Mayor of Paris Anne Hidalgo and the UN Secretary-General's Special Envoy for Cities and Climate Change Michael R. Bloomberg during the
2015 United Nations Climate Change Conference
The 2015 United Nations Climate Change Conference, COP 21 or CMP 11 was held in Paris, France, from 30 November to 12 December 2015. It was the 21st yearly session of the United Nations Climate Change conference, Conference of the Parties (COP) ...
.
In August 2016, Mayor of
Paris
Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...
Anne Hidalgo
Ana María "Anne" Hidalgo Aleu (, ; born 19 June 1959) is a Spanish-French politician who has served as Mayor of Paris since 2014, the first woman to hold the office. She is a member of the Socialist Party (France), Socialist Party (PS).
Hidalg ...
became C40's first chairwoman after being voted in unanimously by the Steering Committee.
Mayor Hidalgo has announced an ambitious agenda for the organization, including plans to focus on securing green financing, supporting compliance with the Global Covenant of Mayors for Climate & Energy, encouraging inclusive and
sustainable growth
Sustainable development is an approach to growth and human development that aims to meet the needs of the present without compromising the ability of future generations to meet their own needs.United Nations General Assembly (1987)''Report of th ...
in cities, and recognizing the leadership of women in tackling climate change.
In December 2016, C40 held its sixth biennial Mayors Summit in Mexico City. The Global Summit, hosted by Mayor of Mexico City Miguel Ángel Mancera, was attended by 1,400 people, including representatives from more than 90 cities.
The current chair of C40 Cities is Mayor Sadiq Khan of London, United Kingdom.
A report in 2019 by C40 Cities, Arup and the University of Leeds set out a number of actions that C40 cities are likely to need to enact to counter the effects of global warming.
Membership
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
In economics, output is the quantity and quality of goods or services produced in a given time period, within a given economic network, whether consumed or used for further production. The economic network may be a firm, industry, or nation. Th ...
, environmental leadership, and the length of a city's membership.
1. Megacities
* ''Population'': City population of 3 million or more, and/or metropolitan area population of 10 million or more, either currently or projected for 2025. OR
* ''GDP'': One of the top 25 global cities, ranked by current GDP output, at purchasing-power parity (PPP), either currently or projected for 2025.
2. Innovator Cities
* Cities that do not qualify as Megacities but have shown ''clear leadership'' in environmental and climate change work.
* An Innovator City must be internationally recognized for barrier-breaking climate work, a leader in the field of
environmental sustainability
Sustainability is a social goal for people to co-exist on Earth over a long period of time. Definitions of this term are disputed and have varied with literature, context, and time. Sustainability usually has three dimensions (or pillars): env ...
, and a regionally recognized “anchor city” for the relevant metropolitan area.
3. Observer Cities
* A short-term category for new cities applying to join the C40 for the first time; all cities applying for Megacity or Innovator membership will initially be admitted as Observers until they meet C40's year-one participation requirements, for up to one year.
* A longer-term category for cities that meet Megacity or Innovator City guidelines and participation requirements, but for local regulatory or procedural reasons, are unable to approve participation as a Megacity or Innovator City expeditiously.
Member cities
C40 has 96 member cities across seven geographic regions.
* Africa:
* East Asia:
** –
Beijing
Beijing, Chinese postal romanization, previously romanized as Peking, is the capital city of China. With more than 22 million residents, it is the world's List of national capitals by population, most populous national capital city as well as ...
** –
Chengdu
Chengdu; Sichuanese dialects, Sichuanese pronunciation: , Standard Chinese pronunciation: ; Chinese postal romanization, previously Romanization of Chinese, romanized as Chengtu. is the capital city of the Chinese province of Sichuan. With a ...
** –
Dalian
Dalian ( ) is a major sub-provincial port city in Liaoning province, People's Republic of China, and is Liaoning's second largest city (after the provincial capital Shenyang) and the third-most populous city of Northeast China (after Shenyang ...
** –
Fuzhou
Fuzhou is the capital of Fujian, China. The city lies between the Min River (Fujian), Min River estuary to the south and the city of Ningde to the north. Together, Fuzhou and Ningde make up the Eastern Min, Mindong linguistic and cultural regi ...
** –
Guangzhou
Guangzhou, Chinese postal romanization, previously romanized as Canton or Kwangchow, is the Capital city, capital and largest city of Guangdong Provinces of China, province in South China, southern China. Located on the Pearl River about nor ...
** –
Hangzhou
Hangzhou, , Standard Mandarin pronunciation: ; formerly romanized as Hangchow is a sub-provincial city in East China and the capital of Zhejiang province. With a population of 13 million, the municipality comprises ten districts, two counti ...
** –
Hong Kong
Hong Kong)., Legally Hong Kong, China in international treaties and organizations. is a special administrative region of China. With 7.5 million residents in a territory, Hong Kong is the fourth most densely populated region in the wor ...
** –
Nanjing
Nanjing or Nanking is the capital of Jiangsu, a province in East China. The city, which is located in the southwestern corner of the province, has 11 districts, an administrative area of , and a population of 9,423,400.
Situated in the Yang ...
** –
Qingdao
Qingdao, Mandarin: , (Qingdao Mandarin: t͡ɕʰiŋ˧˩ tɒ˥) is a prefecture-level city in the eastern Shandong Province of China. Located on China's Yellow Sea coast, Qingdao was long an important fortress. In 1897, the city was ceded to G ...
** –
Shanghai
Shanghai, Shanghainese: , Standard Chinese pronunciation: is a direct-administered municipality and the most populous urban area in China. The city is located on the Chinese shoreline on the southern estuary of the Yangtze River, with the ...
** –
Shenzhen
Shenzhen is a prefecture-level city in the province of Guangdong, China. A Special economic zones of China, special economic zone, it is located on the east bank of the Pearl River (China), Pearl River estuary on the central coast of Guangdong ...
** –
Wuhan
Wuhan; is the capital of Hubei, China. With a population of over eleven million, it is the most populous city in Hubei and the List of cities in China by population, eighth-most-populous city in China. It is also one of the nine National cent ...
** –
Zhenjiang
Zhenjiang, alternately romanized as Chinkiang, is a prefecture-level city in Jiangsu Province, China. It lies on the southern bank of the Yangtze River near its intersection with the Grand Canal. It is opposite Yangzhou (to its north) and ...
** –
Tokyo
Tokyo, officially the Tokyo Metropolis, is the capital of Japan, capital and List of cities in Japan, most populous city in Japan. With a population of over 14 million in the city proper in 2023, it is List of largest cities, one of the most ...
** –
Yokohama
is the List of cities in Japan, second-largest city in Japan by population as well as by area, and the country's most populous Municipalities of Japan, municipality. It is the capital and most populous city in Kanagawa Prefecture, with a popu ...
** –
Seoul
Seoul, officially Seoul Special Metropolitan City, is the capital city, capital and largest city of South Korea. The broader Seoul Metropolitan Area, encompassing Seoul, Gyeonggi Province and Incheon, emerged as the world's List of cities b ...
* Europe:
** –
Copenhagen
Copenhagen ( ) is the capital and most populous city of Denmark, with a population of 1.4 million in the Urban area of Copenhagen, urban area. The city is situated on the islands of Zealand and Amager, separated from Malmö, Sweden, by the ...
** –
Paris
Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...
** –
Berlin
Berlin ( ; ) is the Capital of Germany, capital and largest city of Germany, by both area and List of cities in Germany by population, population. With 3.7 million inhabitants, it has the List of cities in the European Union by population withi ...
** –
Heidelberg
Heidelberg (; ; ) is the List of cities in Baden-Württemberg by population, fifth-largest city in the States of Germany, German state of Baden-Württemberg, and with a population of about 163,000, of which roughly a quarter consists of studen ...
** –
Athens
Athens ( ) is the Capital city, capital and List of cities and towns in Greece, largest city of Greece. A significant coastal urban area in the Mediterranean, Athens is also the capital of the Attica (region), Attica region and is the southe ...
** –
Milan
Milan ( , , ; ) is a city in northern Italy, regional capital of Lombardy, the largest city in Italy by urban area and the List of cities in Italy, second-most-populous city proper in Italy after Rome. The city proper has a population of nea ...
** –
Rome
Rome (Italian language, Italian and , ) is the capital city and most populated (municipality) of Italy. It is also the administrative centre of the Lazio Regions of Italy, region and of the Metropolitan City of Rome. A special named with 2, ...
** –
Venice
Venice ( ; ; , formerly ) is a city in northeastern Italy and the capital of the Veneto Regions of Italy, region. It is built on a group of 118 islands that are separated by expanses of open water and by canals; portions of the city are li ...
** –
Amsterdam
Amsterdam ( , ; ; ) is the capital of the Netherlands, capital and Municipalities of the Netherlands, largest city of the Kingdom of the Netherlands. It has a population of 933,680 in June 2024 within the city proper, 1,457,018 in the City Re ...
** –
Rotterdam
Rotterdam ( , ; ; ) is the second-largest List of cities in the Netherlands by province, city in the Netherlands after the national capital of Amsterdam. It is in the Provinces of the Netherlands, province of South Holland, part of the North S ...
** –
Oslo
Oslo ( or ; ) is the capital and most populous city of Norway. It constitutes both a county and a municipality. The municipality of Oslo had a population of in 2022, while the city's greater urban area had a population of 1,064,235 in 2022 ...
** –
Warsaw
Warsaw, officially the Capital City of Warsaw, is the capital and List of cities and towns in Poland, largest city of Poland. The metropolis stands on the Vistula, River Vistula in east-central Poland. Its population is officially estimated at ...
** –
Lisbon
Lisbon ( ; ) is the capital and largest city of Portugal, with an estimated population of 567,131, as of 2023, within its administrative limits and 3,028,000 within the Lisbon Metropolitan Area, metropolis, as of 2025. Lisbon is mainlan ...
** –
Moscow
Moscow is the Capital city, capital and List of cities and towns in Russia by population, largest city of Russia, standing on the Moskva (river), Moskva River in Central Russia. It has a population estimated at over 13 million residents with ...
** –
Barcelona
Barcelona ( ; ; ) is a city on the northeastern coast of Spain. It is the capital and largest city of the autonomous community of Catalonia, as well as the second-most populous municipality of Spain. With a population of 1.6 million within c ...
** –
Madrid
Madrid ( ; ) is the capital and List of largest cities in Spain, most populous municipality of Spain. It has almost 3.5 million inhabitants and a Madrid metropolitan area, metropolitan area population of approximately 7 million. It i ...
** –
Stockholm
Stockholm (; ) is the Capital city, capital and List of urban areas in Sweden by population, most populous city of Sweden, as well as the List of urban areas in the Nordic countries, largest urban area in the Nordic countries. Approximately ...
** –
Istanbul
Istanbul is the List of largest cities and towns in Turkey, largest city in Turkey, constituting the country's economic, cultural, and historical heart. With Demographics of Istanbul, a population over , it is home to 18% of the Demographics ...
** –
London
London is the Capital city, capital and List of urban areas in the United Kingdom, largest city of both England and the United Kingdom, with a population of in . London metropolitan area, Its wider metropolitan area is the largest in Wester ...
* South America:
** –
Buenos Aires
Buenos Aires, controlled by the government of the Autonomous City of Buenos Aires, is the Capital city, capital and largest city of Argentina. It is located on the southwest of the Río de la Plata. Buenos Aires is classified as an Alpha− glob ...
** –
Curitiba
Curitiba () is the capital and largest city in the state of Paraná (state), Paraná in Southern Brazil. The city's population was 1,773,718 , making it the List of cities in Brazil by population, eighth most populous city in Brazil and the larg ...
** –
Rio de Janeiro
Rio de Janeiro, or simply Rio, is the capital of the Rio de Janeiro (state), state of Rio de Janeiro. It is the List of cities in Brazil by population, second-most-populous city in Brazil (after São Paulo) and the Largest cities in the America ...
** –
São Paulo
São Paulo (; ; Portuguese for 'Paul the Apostle, Saint Paul') is the capital of the São Paulo (state), state of São Paulo, as well as the List of cities in Brazil by population, most populous city in Brazil, the List of largest cities in the ...
** –
Salvador
** –
Santiago
Santiago (, ; ), also known as Santiago de Chile (), is the capital and largest city of Chile and one of the largest cities in the Americas. It is located in the country's central valley and is the center of the Santiago Metropolitan Regi ...
** –
Bogotá
Bogotá (, also , , ), officially Bogotá, Distrito Capital, abbreviated Bogotá, D.C., and formerly known as Santa Fe de Bogotá (; ) during the Spanish Imperial period and between 1991 and 2000, is the capital city, capital and largest city ...
** –
Medellín
Medellín ( ; or ), officially the Special District of Science, Technology and Innovation of Medellín (), is the List of cities in Colombia, second-largest city in Colombia after Bogotá, and the capital of the department of Antioquia Departme ...
** –
Quito
Quito (; ), officially San Francisco de Quito, is the capital city, capital and second-largest city of Ecuador, with an estimated population of 2.8 million in its metropolitan area. It is also the capital of the province of Pichincha Province, P ...
** –
Lima
Lima ( ; ), founded in 1535 as the Ciudad de los Reyes (, Spanish for "City of Biblical Magi, Kings"), is the capital and largest city of Peru. It is located in the valleys of the Chillón River, Chillón, Rímac River, Rímac and Lurín Rive ...
** –
Caracas
Caracas ( , ), officially Santiago de León de Caracas (CCS), is the capital and largest city of Venezuela, and the center of the Metropolitan Region of Caracas (or Greater Caracas). Caracas is located along the Guaire River in the northern p ...
* North America:
** –
Montreal
Montreal is the List of towns in Quebec, largest city in the Provinces and territories of Canada, province of Quebec, the List of the largest municipalities in Canada by population, second-largest in Canada, and the List of North American cit ...
** –
Toronto
Toronto ( , locally pronounced or ) is the List of the largest municipalities in Canada by population, most populous city in Canada. It is the capital city of the Provinces and territories of Canada, Canadian province of Ontario. With a p ...
** –
Vancouver
Vancouver is a major city in Western Canada, located in the Lower Mainland region of British Columbia. As the List of cities in British Columbia, most populous city in the province, the 2021 Canadian census recorded 662,248 people in the cit ...
** –
Guadalajara
Guadalajara ( ; ) is the capital and the most populous city in the western Mexican List of states of Mexico, state of Jalisco, as well as the most densely populated municipality in Jalisco. According to the 2020 census, the city has a population ...
** –
Mexico City
Mexico City is the capital city, capital and List of cities in Mexico, largest city of Mexico, as well as the List of North American cities by population, most populous city in North America. It is one of the most important cultural and finan ...
** –
Austin
** –
Boston
Boston is the capital and most populous city in the Commonwealth (U.S. state), Commonwealth of Massachusetts in the United States. The city serves as the cultural and Financial centre, financial center of New England, a region of the Northeas ...
** –
Chicago
Chicago is the List of municipalities in Illinois, most populous city in the U.S. state of Illinois and in the Midwestern United States. With a population of 2,746,388, as of the 2020 United States census, 2020 census, it is the List of Unite ...
** –
Houston
Houston ( ) is the List of cities in Texas by population, most populous city in the U.S. state of Texas and in the Southern United States. Located in Southeast Texas near Galveston Bay and the Gulf of Mexico, it is the county seat, seat of ...
** –
Phoenix
** –
Los Angeles
Los Angeles, often referred to by its initials L.A., is the List of municipalities in California, most populous city in the U.S. state of California, and the commercial, Financial District, Los Angeles, financial, and Culture of Los Angeles, ...
** –
Miami
Miami is a East Coast of the United States, coastal city in the U.S. state of Florida and the county seat of Miami-Dade County, Florida, Miami-Dade County in South Florida. It is the core of the Miami metropolitan area, which, with a populat ...
** –
New Orleans
New Orleans (commonly known as NOLA or The Big Easy among other nicknames) is a Consolidated city-county, consolidated city-parish located along the Mississippi River in the U.S. state of Louisiana. With a population of 383,997 at the 2020 ...
** –
New York City
New York, often called New York City (NYC), is the most populous city in the United States, located at the southern tip of New York State on one of the world's largest natural harbors. The city comprises five boroughs, each coextensive w ...
** –
Philadelphia
Philadelphia ( ), colloquially referred to as Philly, is the List of municipalities in Pennsylvania, most populous city in the U.S. state of Pennsylvania and the List of United States cities by population, sixth-most populous city in the Unit ...
** –
Portland
** –
San Francisco
San Francisco, officially the City and County of San Francisco, is a commercial, Financial District, San Francisco, financial, and Culture of San Francisco, cultural center of Northern California. With a population of 827,526 residents as of ...
** –
Seattle
Seattle ( ) is the most populous city in the U.S. state of Washington and in the Pacific Northwest region of North America. With a population of 780,995 in 2024, it is the 18th-most populous city in the United States. The city is the cou ...
** –
Washington, DC
Washington, D.C., formally the District of Columbia and commonly known as Washington or D.C., is the capital city and Federal district of the United States, federal district of the United States. The city is on the Potomac River, across from ...
* South and West Asia:
** –
Dhaka
Dhaka ( or ; , ), List of renamed places in Bangladesh, formerly known as Dacca, is the capital city, capital and list of cities and towns in Bangladesh, largest city of Bangladesh. It is one of the list of largest cities, largest and list o ...
** –
Bengaluru
Bengaluru, also known as Bangalore (List of renamed places in India#Karnataka, its official name until 1 November 2014), is the Capital city, capital and largest city of the southern States and union territories of India, Indian state of Kar ...
** –
Chennai
Chennai, also known as Madras (List of renamed places in India#Tamil Nadu, its official name until 1996), is the capital city, capital and List of cities in Tamil Nadu by population, largest city of Tamil Nadu, the southernmost states and ...
** –
Jaipur
Jaipur (; , ) is the List of state and union territory capitals in India, capital and the List of cities and towns in Rajasthan, largest city of the north-western States and union territories of India, Indian state of Rajasthan. , the city had ...
** –
Kolkata
Kolkata, also known as Calcutta ( its official name until 2001), is the capital and largest city of the Indian state of West Bengal. It lies on the eastern bank of the Hooghly River, west of the border with Bangladesh. It is the primary ...
** –
Mumbai
Mumbai ( ; ), also known as Bombay ( ; its official name until 1995), is the capital city of the Indian state of Maharashtra. Mumbai is the financial capital and the most populous city proper of India with an estimated population of 12 ...
** –
New Delhi
New Delhi (; ) is the Capital city, capital of India and a part of the Delhi, National Capital Territory of Delhi (NCT). New Delhi is the seat of all three branches of the Government of India, hosting the Rashtrapati Bhavan, New Parliament ...
** -
Ahmedabad
Ahmedabad ( ), also spelled Amdavad (), is the most populous city in the Indian state of Gujarat. It is the administrative headquarters of the Ahmedabad district and the seat of the Gujarat High Court. Ahmedabad's population of 5,570,585 ...
** –
Tel Aviv
Tel Aviv-Yafo ( or , ; ), sometimes rendered as Tel Aviv-Jaffa, and usually referred to as just Tel Aviv, is the most populous city in the Gush Dan metropolitan area of Israel. Located on the Israeli Mediterranean coastline and with a popula ...
** –
Amman
Amman ( , ; , ) is the capital and the largest city of Jordan, and the country's economic, political, and cultural center. With a population of four million as of 2021, Amman is Jordan's primate city and is the largest city in the Levant ...
** –
Karachi
Karachi is the capital city of the Administrative units of Pakistan, province of Sindh, Pakistan. It is the List of cities in Pakistan by population, largest city in Pakistan and 12th List of largest cities, largest in the world, with a popul ...
** –
Dubai
Dubai (Help:IPA/English, /duːˈbaɪ/ Help:Pronunciation respelling key, ''doo-BYE''; Modern Standard Arabic, Modern Standard Arabic: ; Emirati Arabic, Emirati Arabic: , Romanization of Arabic, romanized: Help:IPA/English, /diˈbej/) is the Lis ...
* Southeast Asia & Oceania:
** –
City of Melbourne
The City of Melbourne is a Local government in Australia, local government area in Victoria, Australia, located in the Melbourne central business district, central city area of Melbourne. In 2021, the city has an area of and had a populati ...
** –
City of Sydney
The City of Sydney is the Local government in Australia, local government area covering the Sydney central business district and surrounding inner city suburbs of the Greater Sydney, New South Wales, Australia. Established by Act of Parliament ...
** –
Jakarta
Jakarta (; , Betawi language, Betawi: ''Jakartè''), officially the Special Capital Region of Jakarta (; ''DKI Jakarta'') and formerly known as Batavia, Dutch East Indies, Batavia until 1949, is the capital and largest city of Indonesia and ...
** –
Kuala Lumpur
Kuala Lumpur (KL), officially the Federal Territory of Kuala Lumpur, is the capital city and a Federal Territories of Malaysia, federal territory of Malaysia. It is the largest city in the country, covering an area of with a census population ...
** –
Auckland
Auckland ( ; ) is a large metropolitan city in the North Island of New Zealand. It has an urban population of about It is located in the greater Auckland Region, the area governed by Auckland Council, which includes outlying rural areas and ...
** –
Quezon City
Quezon City (, ; ), also known as the City of Quezon and Q.C. (read and pronounced in Filipino language, Filipino as Kyusi), is the richest and List of cities in the Philippines, most populous city in the Philippines. According to the 2020 c ...
** –
Singapore
Singapore, officially the Republic of Singapore, is an island country and city-state in Southeast Asia. The country's territory comprises one main island, 63 satellite islands and islets, and one outlying islet. It is about one degree ...
** –
Bangkok
Bangkok, officially known in Thai language, Thai as Krung Thep Maha Nakhon and colloquially as Krung Thep, is the capital and most populous city of Thailand. The city occupies in the Chao Phraya River delta in central Thailand and has an estim ...
** –
Hanoi
Hanoi ( ; ; ) is the Capital city, capital and List of cities in Vietnam, second-most populous city of Vietnam. The name "Hanoi" translates to "inside the river" (Hanoi is bordered by the Red River (Asia), Red and Black River (Asia), Black Riv ...
** –
Ho Chi Minh City
Ho Chi Minh City (HCMC) ('','' TP.HCM; ), commonly known as Saigon (; ), is the most populous city in Vietnam with a population of around 14 million in 2025.
The city's geography is defined by rivers and canals, of which the largest is Saigo ...
Climate Positive
Affiliations
Partners
C40 is a member of The People's Vaccine Alliance. Additional partners include:
*
Clinton Foundation
The Clinton Foundation (founded in 2001 as the William J. Clinton Presidential Foundation, and renamed in 2013 as the Bill, Hillary & Chelsea Clinton Foundation) is a nonprofit organization under section 501(c)(3) of the U.S. tax code. It was e ...
*
Institute for Transportation and Development Policy
An institute is an organizational body created for a certain purpose. They are often research organisations (research institutes) created to do research on specific topics, or can also be a professional body.
In some countries, institutes c ...
(ITDP)
*
International Council for Local Environmental Initiatives (ICLEI)
*
International Council on Clean Transportation (ICCT)
*
United Cities and Local Governments (UCLG)
*
World Bank
The World Bank is an international financial institution that provides loans and Grant (money), grants to the governments of Least developed countries, low- and Developing country, middle-income countries for the purposes of economic development ...
*
World Resources Institute
The World Resources Institute (WRI) is a global research non-profit organization established in 1982 with funding from the MacArthur Foundation under the leadership of James Gustave Speth. Subsequent presidents include Jonathan Lash (1993– ...
(WRI)
Funding
C40's work is made possible by three strategic funders:
Bloomberg Philanthropies,
Children's Investment Fund Foundation and
Realdania.
Additional funding comes from:
See also
*
Climate change adaptation
Climate change adaptation is the process of adjusting to the effects of climate change, both current and anticipated.IPCC, 2022Annex II: Glossary
*Climate change mitigation">öller, V., R. van Diemen, J.B.R. Matthews, C. Méndez, S. Semenov, J.S. Fuglestvedt, A. Reisinger ...
*Climate change mitigation
*Covenant of Mayors
*Energy conservation
*ICLEI, ICLEI – Local Governments for Sustainability
*Individual and political action on climate change
*List of largest cities
*London Climate Change Agency
*
, Vol. 2, pp. 119–137, 2008