Our Team

Lauren is the Director for London Coordination and Summit Delivery at C40. In this role, she is responsible for the successful delivery of C40’s World Mayors Summit in 2025 as well as ensuring that the priorities and vision of C40’s Co-Chair, the Mayor of London, are being realised.

Before joining C40, Lauren worked at the Greater London Authority in the Mayor of London’s international relations team, where she designed and implemented international programmes for the Mayor. She has also worked in the UK Parliament where she worked with overseas parliaments, focussing on issues such as sustainability, human rights and gender equality. Prior to this she worked at the Commonwealth Secretariat and at the charity Minority Rights Group International.

She holds an MSc. in Development Studies from SOAS and is a qualified Prince2 Practitioner.

Anya (Anna) Dorant-Hayes serves as Senior Executive Assistant to the Executive Director.

Based in London, Anya provides daily support to the Executive Director. She is responsible for diary and inbox management, international and domestic travel logistics, developing and coordinating the preparation of background material, and dealing with internal and external enquiries. She also works closely with the Deputy Chief of Staff on the delivery of special projects.

Anya has extensive experience of working in support roles for C-suite executives within the academia, publishing and charity sectors. She spent a large part of her career at Chatham House (The Royal Institute of International Affairs) as EA to the Chief Executive where she has deepened her interest in climate change and sustainability issues.

Anya graduated from Birkbeck College, University of London with a BA in Spanish and Latin American Studies. She speaks Polish, Spanish and English.

Ruchi is the Senior Events Manager for the C40 x GCoM Joint Program. In this role, Ruchi oversees the seamless execution of world-leading international events that strategically advance the Joint Program’s mission.

With over 15 years of experience, Ruchi began her career at the Clinton Global Initiative before transitioning to Google, where she developed a deep expertise in leveraging events for social impact causes.

Ruchi holds a Bachelor’s degree in Economics from Columbia University, Barnard College.

John Baimba Sesay is the Senior Manager, Communications, for the C40 Cities Freetown Co-Chair’s Office. In this role, John plays a critical role within C40’s Governance and Communications teams, in showcasing the climate leadership of the C40 co-chair nationally and internationally.

John joined C40 in June 2024. Before that, he was with the United Nations Population Fund’s Sierra Leone Country Office where he was responsible for managing all media and communication-related work. John’s background in information dissemination, cultural diplomacy, and media relations enables him to oversee content creation for print media, broadcast media, and digital media and facilitate high-level media engagements.

John served as the Information Attaché for the Sierra Leone Embassy in the People’s Republic of China for six years. John holds a Bachelor’s and Master’s degree both in Mass Communications from Fourah Bay College, University of Sierra Leone.

Sallieu Kanu serves as Senior Manager, Youth Engagement and Campaigns at the C40 Co-Chair’s Office in Freetown. Sallieu possesses an extensive professional background and strong experience working with government leadership. He has a deep understanding of climate governance, backed by a wealth of years of experience as a Senior Project Lead for the clean cooking program at Freetown City Council, where he worked closely with C40 Co-Chair and Mayor Yvonne Aki-Sawyerr. He is passionate about advancing youth-led climate actions in urban areas, focusing particularly on the needs of poor and vulnerable communities.

Sallieu has successfully led and implemented multiple projects funded by organizations such as World Bank, the Foreign Commonwealth and Development Office (FCDO), UN-Habitat, the European Union, Bosch Foundation, and Bloomberg Philanthropies. These projects have spanned areas including water, energy transition, COVID-19 preparedness and response, urban farming, waste valorization, and tree-tracking trading.

Furthermore, Sallieu has built and nurtured partnerships with a variety of stakeholders, compassing government partnerships, the private sector, youth groups and civil society organizations.

Pius joined C40 as Mayor Aki-Sawyerr’s Head of Coordination in the Co-Chair’s Office in April 2024. He undertakes this connecting role between C40, London and the Freetown Mayor’s Office, and is responsible for all external engagements for the co-chair, all internal and external briefings to the co-chair and her wider team and feedback to C40 teams.

He comes with more than 12 years of experience working at government offices to support shaping and implementing their vision on sectors like waste management and the climate; investing in and managing businesses around green and waste management technologies and services; and working in the INGO sector in coordination and leadership positions. Pius has developed significant experience of working with municipal governments, with senior officials and managing micro, meso, and macro projects based on cities’ needs.

He has worked with a diversity of donors through the coordination of numerous consulting assignments and projects funded by the multilateral and UN-funding agencies including the World Bank Group, AfDB, GIZ, FCDO, JICA, UNICEF, USAID, and other public and private sector clients including various ministries and government agencies.

Fatmata Mary Kanyako serves as C40’s Administrative Assistant at the Freetown Co-Chairs office, in Freetown, Sierra Leone. She worked as Human Resource Manager in the hospitality industry and was later employed by the Tony Blair Institute for Global Change to support the Mayor of Freetown, Yvonne Aki-Sawyerr for the past 6 years as Executive Assistant.

Fatmata is an experienced administrative professional with over a decade of experience supporting leaders in the climate service sector. She has a proactive and results-driven approach to her work, backed by an acute knowledge of office systems and procedures. She has excellent organizational and communications skills, ranging from updating and managing information materials to handling official correspondences in an increasingly technology-focused workforce.

Fatmata is dedicated and passionate about her work and is very supportive in achieving Mayor Aki-Sawyerr’s goal to Transform Freetown – Transforming Lives.

Idan Sasson is a Senior Manager for the C40 x GCoM Joint Program, where he is focused on the Subnational Climate Action Leadership Exchange (SCALE). Prior to joining C40, Idan was responsible for global urban climate finance programs at CDP and the Cities Climate Finance Leadership Alliance, advancing climate infrastructure projects towards implementation at scale. 

Idan has worked extensively with cities around the world on urban sustainability and resilience issues, having worked at Rebuild by Design – 100 Resilient Cities, and the New York City Department of Park and Recreation on strategies for inclusive community and stakeholder engagement to address climate-related challenges. Idan holds a Master’s Degree from the London School of Economics and Political Science in Environment and Development and a B.A. from NYU’s Gallatin School in Sustainable Urban Development.

Julie Ciardullo is the Head of Joint Programme Strategy, where she is responsible for driving strategic development and implementation of the C40 x GCoM Joint Programme. Before joining C40, Julie spent 10 years working for the Los Angeles Mayor’s Office, where she was most recently appointed the Director of Climate Resilience. Prior to that, she was a Senior Policy Advisor and the Director of the Office of the C40 Chair during Mayor Eric Garcetti’s term as Chair of C40.

Julie began her career as an attorney, practising corporate law at Kramer Levin Naftalis & Frankel LLP in New York City, and later, served as a fellow at the Sabin Center for Climate Change Law. She received her J.D. from Columbia Law School and her B.A. in Political Science and International Relations from UCLA.

Rebecca works in the Political Strategy and Leadership Support department and is the C40 Steering Committee Senior Manager responsible for supporting the Office of the C40 Chair by managing the processes of the Steering Committee. Prior to this, Rebecca was the Deputy Managing Director of the political organisation STRING, bringing together European cities and regions for sustainable infrastructure and sustainability. She has also worked for the Swedish/Danish cross-border cooperation the Oresund Committee and has experience in transport planning, strategy and stakeholder management from Newcastle City Council in the UK.

Rebecca’s academic background is in political science, and she has a Master’s degree from Lund University in Sweden and a Bachelor’s degree from the University of Northumbria in the UK.

Julieta is C40’s Executive Office Project Manager for the C40 Inc Board, its Finance and Audit Committee and the UK Board, working on the C40 Internal Communications strategy and various special projects requiring coordination from the Executive Office. Julieta initially joined C40 supporting the 2022 C40 World Mayors Summit delivery and is based in Buenos Aires, Argentina.

Her work experience is related to sustainability, working for the City of Buenos Aires with a special focus on healthy mobility, city development and the implementation of cooperation projects with international organisations and strategic stakeholders in the public and private sectors.

She holds a degree in International Relations (USAL – Buenos Aires) and is working on a Master’s Degree in Urban Economics (UTDT – Buenos Aires).

Alice serves as Deputy Chief of Staff and Head of the Executive Office. In this role, Alice oversees the smooth functioning of the Executive Director’s private office, his international engagement, and the coordination of C40’s global leadership strategy which aims to use the collective voice and actions of C40’s mayors and partners to help the world avoid climate breakdown. Alice has worked at C40 since 2019, working on various projects from leading the 2022 C40-Bloomberg Philanthropies Awards to coordinating C40’s COVID-19 response and rapid response strategy.

Alice has a BA in Geography from the University of Manchester, including a year at the University of British Columbia, Vancouver. She is currently studying for an MSc in Spatial Planning at UCL.

Emily-Jayne serves as Global Events & Special Projects Officer at C40. Based in London, she supports the delivery of C40’s internationally recognised events and those by its mayoral global leadership.

Prior to joining C40, Emily-Jayne served as the Events and Operations Coordinator at the World Energy Council, where she helped to organise the Council’s flagship events, such as the World Energy Congress and World Energy Leader’s Summit.

Emily-Jayne has a degree in Earth & Environmental Science from Lancaster University, with a year spent at the University of Kentucky to focus on Natural Resources.

As Director of the Executive Office, Pauline is responsible for liaising with the Bloomberg Philanthropies environment team on projects and activities related to C40 and Michael Bloomberg’s position as C40 Board President.

Pauline initially joined C40 as Project Manager for the Women4Climate Tech Challenge, a global competition designed to promote and support innovation and climate solutions from women in the tech community. She started her career in e-commerce, where she worked as a localisation and operations manager for six years, before taking part in the On Purpose leadership programme to transition her career into the environmental impact sector.

She since worked with sustainability leader and carpet manufacturer Interface, designing and implementing circular solutions to reduce waste, and developed a new portfolio of services for the innovation foundation Nesta.

Sarah serves as Research Manager, supporting the Executive Director with research projects, speeches, articles and blogs. Sarah joined C40 after completing an MSc in Sustainable Resource Economics, Transitions and Policy at University College London. Her dissertation focussed on city-level energy projects. She also holds a BA in Middle Eastern Languages from the University of Manchester and has lived and worked in a number of global cities, including Amsterdam, Tel Aviv, Jerusalem and Alexandria. In her spare time, Sarah enjoys hiking and reading.

David Miller is the Managing Director of the C40 Centre for City Climate Policy and Economy.

Mr. Miller was Mayor of Toronto from 2003 to 2010 and served as Chair of C40 Cities from 2008 until 2010. Under his leadership, Toronto became widely admired internationally for its environmental leadership, economic strength and social integration. He is a leading advocate for the creation of sustainable urban economies.

Mr. Miller has held a variety of public and private positions and served as Future of Cities Global Fellow at Polytechnic Institute of New York University from 2011 to 2014. He has an Honorary Doctorate from the University of Waterloo in Environmental Studies, an Honorary Doctor of Laws from York University and is currently Executive in Residence at the University of Victoria. He is the author of ‘Solved, how the great cities of the world are fixing the climate crisis‘, (University of Toronto Press).

David Miller is a Harvard-trained economist and professionally is a lawyer. He and his wife, lawyer Jill Arthur, are the parents of two children.

Brendan serves as Senior Manager of Global Events & Special Projects.

In this role, Brendan draws on his project management skills to assist in the end-to-end delivery of world-leading international events, communication campaigns and initiatives that showcase the work of C40 Cities.

Prior to joining C40, Brendan worked for several years in different capacities within the music industry, specialising in events and venue management, primarily for VICE Media-owned and independent venues in London. He has also worked in the social care sector, for an educational NGO in Hong Kong, and has volunteered for several NGOs both in the UK and abroad, focusing on research, copywriting, data protection, and refugee participation in sports.

Brendan holds a Master’s degree in Environment, Development and Policy from the University of Sussex and a Bachelor’s degree in Music and Entertainment Industry Management from the University of Hertfordshire.

Anna serves as the Managing Director of Governance and Executive Engagement. Anna supports the Executive Director and oversees relationships with key C40 strategic funders. In particular, she provides support to the Executive Director in managing the Board of Directors, supporting the C40’s Chair’s Office functions and managing the Governance and Fundraising teams. Before joining C40 in 2015, Anna spent seven years living and working in East Asia, including Hong Kong, Beijing, and Chengdu. Prior, Anna worked in the Mayor of London’s Office for the climate change and sustainable transport adviser, and was part of the team who developed London’s first Climate Change Action Plan. Anna holds a BA in Philosophy and Political Science from the University of Birmingham, UK and is learning to speak Mandarin Chinese.

Mark’s aim as Executive Director is to ensure that C40 Cities is equally focused on science-based climate action and political leadership for climate justice. C40 has grown dramatically in scope and ambition under Mark’s tenure and its 300 staff now support nearly 100 of the world’s leading cities, representing around 700 million residents.

Mark has been named one of the world’s most influential leaders driving climate action as a ‘defender’ by TIME as part of its inaugural TIME100 Climate list. Prior to joining C40 Cities, Mark was a director at pioneering engineering and design firm Arup; and previous to that role, he was a senior adviser to the Mayor of London. Outside of work, he can usually be found either up a mountain or proclaiming the discovery of a great new band.