Vivian serves as the Technical Head of Breathe Cities, Southeast Asia, and Senior Advisor, Air Quality and Health. As part of the Air Quality team’s technical assistance program, Vivian is responsible for coordinating in-house modelling, analysis, report writing, and public communication in support of the cities’ air quality planning and policy development, as well as strengthening connections within C40 and with key C40 partner stakeholders.
Vivian is an air pollution epidemiologist with over 13 years of research experience, focusing on air pollution/environmental health, urban health, chronic diseases and well-being, and “big data” quantitative research methods. Before joining C40, she worked at Vital Strategies, a global public health organization, where she made the case for addressing air pollution from a public health perspective, increasing commitment and capacity of key stakeholders to strengthen air quality management to promote public health, and informing the public about the risks of air pollution. She also has hands-on public health experience, working as an epidemiologist at the Massachusetts Department of Public Health in Boston, USA, and as a Principal Scientist at the National Environment Agency in Singapore.
She holds a BSc in Biology from the University of Washington (Seattle, USA), a Masters in Public Health from Boston University (Boston, USA), and a PhD in Public Health from the Chinese University of Hong Kong (China). She is currently based in Singapore.
Vrilly Rondonuwu serves as City Adviser for Jakarta, Indonesia. In this role, she is one of the key parts of the Regional and Mayoral Engagement team to engage the city in the implementation of the climate action plan and the fulfilment of C40’s Leadership Standards, including supporting C40 as required during the transition of city administrations, representing C40, and liaising with external partners working with the city on relevant issues.
Vrilly has over ten years’ experience, both in the government and non-government environment from project planning, implementation and monitoring and evaluation. Her extensive professional work on climate started with assisting the Chair of the UNFCCC Subsidiary Body for Implementation in the year of 2009, working with various people and organizations.
Before joining C40, Vrilly worked as a consultant in the fields of environment, resource efficiency, and climate change at various international organizations e.g., as a short-term consultant to support the coordination and data collection for the ASEAN Resource Panel at UNESCAP; as a national short-term consultant at World Bank Indonesia for the Climate Change Institutional Assessment project; as an RECP policy expert and networking coordinator at ICPC for the RECP Indonesia project supported by UNIDO; on the coordination desk on behalf of the Foundation for Sustainable Development as part of the Consumer Information Programme for SCP–UNEP; and as a technical officer/policy adviser at GTZ for their Climate Change programme.
She completed her Master’s of Ministry in Pastoral Counseling at Jakarta Theology Seminary, and earned a BSc in Quality Performance Management and Information Technology at Marquette University in Milwaukee, USA.
Wanjiku Ngare is a Senior Manager in the City Finance Programme at C40. She is responsible for overseeing a portfolio of special projects and partnerships, supporting sectoral finance staff, program management, and supporting internal team strategy development and operations.
Wanjiku is a passionate urbanist with experience in management consulting and project finance. Prior to this role, she was an operations senior associate at Instiglio Inc and an associate management consultant at Dalberg Advisors. She worked on cross-sectoral projects for diverse clients, including large foundations, multilateral development banks, and bilateral development finance institutions. Her work spanned from identifying and addressing barriers in scaling the deployment of pico to microgrid solar in East African countries; to identifying key constraints to economic development in Kosovo. She began her career as a Project Finance Analyst at Sol Systems LLC, a leading renewable energy financier and developer in the United States.
Wanjiku holds a Bachelor’s in International Affairs from Georgetown University and a Master’s in Urban Planning from the Harvard Graduate School of Design.
Wenwen Chen serves as Operations Manager, China Office. In this role, she is responsible for managing the Corporate Services deliverables within China.
Prior to joining C40, Wenwen worked as a Program Operation Manager for Peking University’s Guanghua School of Management. Before that, Wenwen served as Vice Director for the International Cooperation Department of the Dragon Design Foundation, where she led the Sino-EU collaborations and activities on sustainable design and green technology. She also worked for the first local Fair Trade organisation in China earlier in her career.
Wenwen holds a Bachelor’s Degree in Agriculture and Ecology from South China Agriculture University and an International MBA from Tsinghua University School of Economics and Management, including one semester exchange programme at ESSEC Business School.
William Andruga serves as C40’s City Adviser, Waste and Methane, in Freetown, Sierra Leone. He has over 10 years of waste management experience in humanitarian, refugee/displaced people’s settlements, municipalities and institutions. William is a civil engineer by training, with a BSc in Civil and Building Engineering and post-graduate studies in project management, waste and sanitation.
William is now undertaking a research-based MSc in Environmental Engineering focusing on GHG emissions reduction and efficient nature-based solid waste treatment methods.
William is excited by new ways to solve complex challenges including piloting projects for untested solutions to generate knowledge and understanding. Andruga is a team player, and team leader and enjoys meeting new people.
William serves as Declaration Manager for C40’s Green and Healthy Streets Declaration. In this role, William coordinates C40 support towards Green and Healthy Streets Declaration signatories and tracks the implementation of the Declaration in cities, helping to accelerate implementation and achieve effective, ambitious and measurable outcomes on decarbonising transport in cities.
Prior to his current role, William was Benefits Research Officer in the Knowledge and Learning Directorate, where he supported cities with making the case for climate action through demonstrating the wider social and economic benefits. He also supported on a number of additional research projects, including The Case for a Green and Just Recovery released by the C40 Global Mayors COVID-19 Recovery Task Force, and Coal-free Cities: The Health and Economic Case for a Clean Energy Revolution.
Wyda is a Programme Officer for C40’s UCAP Climate Action Implementation (CAI) Programme in the Southeast Asia team. She supports programme management, planning and coordination across the Climate Action Implementation team and with other global C40 teams. Wyda holds an M.Eng in Urban and Regional Planning from the University of Gadjah Mada, Indonesia.
Wyda has worked with various consulting firms on spatial planning and has broadened her experience on the social aspects of the palm oil and timber sectors through her work with the Earthworm Foundation. She has experience assisting more than 50 palm oil and timber producers in meeting sustainability standards, focusing on the social aspects.
Before joining C40, Wyda worked as NDPE (No Deforestation, No Peat Development, and No Exploitation) policy implementation lead in one of POSCO International’s subsidiaries, a Korean multinational corporation based in Indonesia.
Xian Zhou serves as the Regional Officer in C40’s China office. In this role, she helps coordinate and facilitate the delivery of the Central East Asia regional team covering member cities across the specified regions.
Xian has rich experience in working in a multi-cultural and cross-functional environment, including diplomatic missions and representative offices of foreign government agencies in China. Before joining C40, Xian worked as a Senior Immigration Officer for the New Zealand Ministry of Business, Innovation & Employment, where she built cooperative relationships with internal and external stakeholders to develop trust and mutual understanding of relevant policies and procedures. Before that, she worked for Lesotho Embassy to China focusing on partnership development and executive support. Xian also planned and managed high-profile events at China World Trade Center. Xian holds a Master’s Degree from Beijing Institute of Technology.
Yana serves as Senior Project Manager within C40’s Ports and Shipping team. She leads C40’s work on Green Shipping Corridors, aimed at catalyzing the shipping transition through innovative multi-level cross-value chain partnerships.
Before joining C40, Yana worked in an environmental non-profit in Brussels, lobbying the EU to adopt ocean protection legislation. For many years, her work in Europe was centred around EU and French advocacy, campaigning, as well as citizen empowerment and mobilization. She is the co-author of 3 studies on eco-anxiety.
Yana holds a Bachelor’s degree in International Relations and a Master’s in European Affairs. She speaks English, French and Russian.
Yasar is the Knowledge Officer in the C40 Cities Finance Facility (CFF), a joint initiative of C40 and GIZ which facilitates access to finance for climate change mitigation and resilience projects in urban areas. In his role, Yasar is part of the delivery of the CFF’s City Academy on Finance and Equity (CAFE) and other knowledge dissemination activities. Yasar joined C40 in November 2022 as an intern working across the Climate Action Implementation and CFF teams, where he supported coordination across the teams and the delivery of events. Before joining C40, Yasar completed his Master’s degree in World History at the University of Cambridge, writing on Kwame Nkrumah and Pan-Africanism in post-colonial Ghana, and before that completed his undergraduate degree in History at the University of Oxford. Prior to C40, he worked with the Cambridge Refugee Resettlement Campaign and Starfish Greathearts.
Yasmin serves as a Programme Officer for the C40 x GCoM Joint Programme, a collaborative initiative funded by Bloomberg Philanthropies. In this role, Yasmin provides vital project management support, facilitates effective communication, and ensures the tracking of key programme data and monitoring and evaluation efforts.
Prior to joining C40, Yasmin worked on the Rooted in Trust project for Internews, a global USAID-funded program that responded to rumours and misinformation related to the COVID-19 pandemic in traditional communities in the North of Brazil. As a Project Officer, Yasmin focused on M&E and reporting, stakeholder liaison, and logistics and event organization. Previously, she also contributed to GEF-funded projects related to sustainable development while working at the UNDP in Brazil.
Yasmin holds a double degree in International Relations and Political Science, as well as a double Master’s degree in International Development and Risk Management from the University of Coimbra in Portugal and Sciences Po Bordeaux in France. Her Master’s thesis provides a historical analysis of the neocolonialist logic in French cooperation towards former colonies in Africa.
Yerim is a City Finance Manager, supporting the delivery of sectoral finance activities across the C40 x Global Covenant of Mayors Joint Programme and the Lowering Organic Waste Methane (LOW-M) initiative.
In her role, Yerim manages the waste pillar of C40’s finance work, coordinating inputs into the LOW-M coalition and helping cities access support for methane mitigation through research, partnerships, and finance solution tools. She also contributes to finance-focused engagements across adaptation, energy, transport, and ports sectors – including investor roundtables, finance academies and tools that enable cities to unlock climate finance. Yerim works closely with the wider team to strengthen programme delivery systems, monitoring, and planning processes.
Previously, Yerim was part of C40’s Inclusive Climate Action (ICA) team, where she supported monitoring, evaluation, and learning, researched climate migration and loss and damage, and helped cities embed equity into their climate action through the ICA Fund and Forum.
Yerim holds a Master’s in Urban Development Planning from University College London. Before joining C40, she worked in public relations and strategic communications across Seoul, Ho Chi Minh City, and Mysore – including leading external relations and co-organising an inter-Korean orchestra project under a UN peacebuilding initiative. She is passionate about climate justice and is committed to making climate finance more inclusive, particularly in underfunded areas like waste and methane abatement.
Ms. Ying Gao is the Head of Regional Coordination and Partnerships, China. She will take the lead to engage with Chinese cities, support the development and delivery of our China strategy and coordinate from both operation and city engagement perspective to build cross-team synergy to support C40 cities in China. Ying has over ten years of experience in the field of sustainable development, on government partnership development, project management and organizational operation. Prior to joining C40, she worked at Ellen Macarthur Foundation to lead the food initiative in China. She also worked for Chinese Foundation – the Qiaonyu Foundation as well as WWF China where she supported the CEO and Chief Conservation Officer in strategic partnerships development, strategy development, social impact investment, projects management and provided trainings on project management for both internal and external colleagues. She holds a Master’s degree from ESC Rennes School of Business. She is also a member of Conservation Coaches Network.
Yuping Qiu is a Programme Officer, C40 China Buildings Programme, supporting the development and implementation of ambitious citywide building energy efficiency initiatives. Prior to joining C40, Yuping worked as an Advisor at the Danish Energy Agency, part of the Danish Ministry of Energy, Utilities and Climate, where she focused on collaboration with the Chinese government supporting UN sustainability goals. Based in the Department for Global Cooperation, Yuping was in charge of energy policy monitoring, report drafting and policy analysis. In addition, she brings experience from the Royal Danish Embassy in China, where she worked with consular affairs. Yuping holds a master’s degree in International Studies from Aarhus University, Denmark.
Zachary Tofias serves as the Director of the Food and Waste Programme at C40. His work supports C40 cities’ transition toward regenerative resource management and reducing emissions through more sustainable consumption. The Food and Waste Programme is helping cities accelerate a worldwide transition to more effective municipal solid waste management, and the implementation of comprehensive solutions that reduce carbon emissions and increase resiliency throughout the urban food system.
Zach has been with the C40 Cities Climate Leadership Group since 2007 in partnership with the Clinton Climate Initiative. Over the course of this time, he has been City Director in Addis Ababa, Ethiopia, created and led the Climate Positive Development Programme, was the head of Urban Planning and Development, and recently was the Interim Director of Adaptation.
Since 2007, Zach has worked around the world with leading cities and the private sector on developing locally relevant solutions for replicable models of making cities more sustainable. Zach has a Master’s degree in Business Administration from Cornell University and a Bachelor’s degree from Middlebury College.
Zarina serves as Head of Implementation in Africa, within the Regions & Mayoral Engagement Team, and leads in the region the C40’s UCAP Climate Action Implementation (CAI) Programme. In this role she works with seven C40 African cities to develop ambitious and robust long-term climate action plans that are compatible with the ambitions of the Paris Climate Agreement.
Prior to this, Zarina worked as a C40 City Adviser to Durban, where she supported the City to develop their Climate Action Plan. Before joining C40, Zarina worked at the National Business Initiative (NBI) South Africa as a project manager for climate change mitigation, where she managed work on the CDP climate change and water programmes in South Africa. She also worked with companies to build capacity and provide best practice guidance on greenhouse gas reporting. Previously, Zarina also worked as a Programme Officer for environmental, water and energy projects at the Academy of Science of South Africa (ASSAf), where she managed a low-carbon cities project, focusing on the City of Durban.
Zarina holds an MSc in Environmental Science and a BSc Honours in Environmental Management from the University of KwaZulu-Natal.
Zermina is the Director of Strategic Communications, Media and Partnerships at C40 Cities, based in London, UK.
In this role, she sets the strategic direction for C40’s communications and media efforts and high-impact partnerships. She is responsible for shaping and executing communications strategies around C40’s milestones and global events.
Zermina also serves as C40 Co-Chair and Mayor Sadiq Khan’s Press Secretary, leading efforts to amplify his leadership on climate action and demonstrate the tangible outcomes of his work as co-chair on the world stage.
Before joining C40, Zermina held positions across local and national government, where she built and led teams delivering high-profile public campaigns and policy communications. She holds a degree in Law and is fluent in four languages.
Zoe leads C40’s Zero Emission Vehicle Network, which supports 20+ cities to accelerate the transition to zero-emission vehicles and roll out charging infrastructure, whilst still creating cities that prioritise walking, cycling and public transport. She also works closely with colleagues to deliver C40’s Zero Emission Area programme and support cities to achieve their commitments under the Green and Healthy Streets Accelerator.
Before C40, Zoe has held roles in a variety of local non-profits, working on issues from healthy food provision, to refugee action, to domestic abuse support. She holds an MA in Conflict, Security and Development, specialising in sustainable development and environmental migration, and a BA in English, both from the University of Exeter, UK.
Zoë Chafe, PhD, MPH is Head of Air Quality and Health Technical Programmes at C40, where she leads C40’s Clean Air Network, the Air Quality Data & Analytics team, and technical working groups. From 2019 to 2022, Zoe led C40’s CAP-AQ project, which created tools to integrate air quality management with climate planning. Zoë works with governments, organisations, and individuals to build an equitable, safe, and healthy future by identifying opportunities to improve air quality.
Zoë has two decades of experience working at the intersection of climate change, air quality, and public health, with a focus on household energy. Her previous work includes contributions to the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report, the Global Energy Assessment, and World Health Organization reports on energy use’s air quality, health, and climate impacts.
Zoë holds a PhD (Energy and Resources) and MPH (Master of Public Health) from the University of California, Berkeley, as well as a bachelor’s degree in human biology from Stanford University. She is a recipient of the National Science Foundation Graduate Research Fellowship and Cornell University’s Atkinson Center Postdoctoral Fellowship.
Zöe is based in London and leads the City-Business Engagement team, supporting C40 Cities to engage with businesses at a local, regional, and global level to support the implementation of their climate action plans. The City-Business Engagement team leads the City-Business Climate Alliance programme and supports efforts to develop public-private collaboration.
Before joining C40, Zöe managed a capacity-building programme for the UK Government, providing technical support to national and local governments across 16 middle-income countries, raising climate ambition and reducing emissions. Prior to this, she led climate for the Urban Systems team at Innovate UK, bringing innovative businesses together with cities. She also worked on research and innovation policy for UKRI USA at the British Embassy in Washington DC. Zöe holds a BSc in Physical Geography from King’s College London and also studied at the University of Chapel Hill in North Carolina.