The Global Ambassadors

The Global Ambassadors are widely recognized for its leadership on divest-invest and climate issues. They support the Summit and endorse its objectives.

Paulo Artaxo

Paulo Artaxo

Paulo Artaxo is professor of environmental physics at the University of São Paulo, Brazil. He worked at Harvard, Stockholm and Lund Universities and at NASA Goddard. He was lead author in several previous IPCC reports (AR4, AR5, IPCC climate geoengineering and others) and is working as a lead author in the IPCC AR6 and the Special Report on Climate Change and Land (SRCCL).

He is a specialist in aerosol particles impact in the radiation balance and its effects on ecosystems, specially Amazonia. His studies on the impact of aerosols from biomass burning on the cloud formation, development and in the hydrological cycle was important for tropical regions. He also worked extensively on urban air pollution issues, with an emphasis on short lived climate forcers (black carbon, aerosols, ozone precursors and methane).

Paulo Artaxo published more than 460 scientific papers and is one of the most cited Brazilian scientists with more than 18,000 scientific citations in the ISI Web of Sciences, with an “H-index” of 75. He has about 41,800 citations on the Google Scholar with an H index of 98. He is a member of the Brazilian Academy of Sciences and the World Academy of Sciences (TWAS). He serves at the UNEP Science Advisory Panel for GEO-6. In 2006, he was elected a fellow of the American Association for the Advancement of Science (AAAS). In 2009 he was awarded with the title of Doctor of Philosophy Honoris Causa of the University of Stockholm, Sweden.

Nnimmo Bassey

Nnimmo Bassey

Nnimmo Bassey is director of the ecological think-tank, Health of Mother Earth Foundation (HOMEF) and member steering committee of Oilwatch International – a network resisting the expansion of fossil fuels extraction in the Global South. He was chair of Friends of the Earth International (FoEI) (2008-2012) and Executive Director of Nigeria’s Environmental Rights Action (1993-2013).

Bassey serves on the boards of a number of non-profit organisation including Global Greengrants Fund, Action Group on Erosion, Technology and Concentration (ETC Group), and of Navdanya International. He was a co-recipient of the 2010 Right Livelihood Award also known as the “Alternative Noble Prize.” In 2012 he received the Rafto Human Rights Award. In 2014 he received Nigeria’s national honour as Member of the Federal Republic (MFR) in recognition of his environmental activism. Bassey is a Fellow of the Nigerian Institute of Architects and has authored books on the environment, architecture and poetry. He is also a Member of the Action Research Network for a Wellbeing Economy in Africa (WE-Africa).

His books include We Thought it Was Oil, But It was Blood – Poetry (Kraft Books, 2002), I will Not Dance to Your Beat – Poetry (Kraft Books, 2011), To Cook a Continent – Destructive Extraction and the Climate Crisis in Africa (Pambazuka Press, 2012) and Oil Politics – Echoes of Ecological War (Daraja Press, 2016). He writes a weekly column, The Instigator, focusing on socio-ecological transformation in The Leadership Newspaper (Nigeria).

Mark Campanale

Mark Campanale *

Mark is the Founder of the Carbon Tracker Initiative and conceived the ‘unburnable carbon’ capital markets thesis. He commissioned and was editor of Unburnable Carbon – Are the World’s Financial Markets Carrying a Carbon Bubble? report that launched us in November 2011. More recently, Mark founded and is Chair of the Fish Tracker Initiative – which focuses on limits to growth in the fisheries space. Mark is responsible for management strategy, board matters and developing their capital markets framework analysis. Their goal is to align capital markets with natural ecological limits to growth.

Prior to forming these groups, Mark had twenty five years experience in sustainable financial markets working for major institutional asset management companies. Mark is a co-founder of some of the first responsible investment funds firstly at Jupiter Asset Management in 1989 with the Ecology Funds, NPI with Global Care, the AMP Capital Sustainable Future Funds, and Henderson Global Investor’s Industries of the Future Funds.

Mark served on the World Business Council for Sustainable Development working group on capital markets leading up to the 1992 Earth Summit; was a Member of the Steering Committee of UNEP Financial Sector Initiative (1999-2003) and continues to advise a number of financial institutions including Tribe Impact Capital and Consilium Capital.

Ellen Dorsey

Ellen Dorsey

Ellen Dorsey is Executive Director of the Wallace Global Fund, a private foundation focused on progressive social change in the fields of environment, democracy, human rights and corporate accountability. Under her leadership, the Fund is recognized for creative philanthropic strategies and mission-related investing. This alignment of programs and investments led the foundation to support the fossil fuel divestment movement since its inception and to launch a new global campaign, Shine, to end energy poverty. Dorsey was awarded the 2016 inaugural Nelson Mandela – Graca Machel Brave Philanthropy Award for launching Divest-Invest Philanthropy, a coalition of over 170 foundations committed to deploying their investments to address the climate crisis and accelerate the clean energy transition.

Dr. Dorsey came to Wallace Global Fund from a series of academic, philanthropic and non-profit leadership positions in the human rights and environmental fields, including serving as Executive Director at the Rachel Carson Institute, launching the Human Rights and Environment program at Amnesty International, and serving as senior program officer in the Heinz Endowment’s Environment Program.

Dorsey holds a doctorate in political science from the University of Pittsburgh. She was a Fulbright Research Fellow in South Africa during that country’s historic transformation. She served on the faculty of several Universities, teaching human rights and environmental sustainability. She has written extensively on effective strategies of non-governmental organizations and social movements. Dorsey is co-author, with Paul J. Nelson, of New Rights Advocacy: Changing Strategies of Development and Human Rights NGOs, Georgetown University Press, 2008.

Christiana Figueres

Christiana Figueres *

Christiana Figueres is a Costa Rican citizen and was the Executive Secretary of the United Nations Framework Convention on Climate Change 2010 – 2016.

During her tenure at the UNFCCC, Ms. Figueres brought together national and sub-national governments, corporations and activists, financial institutions and NGOs to jointly deliver the historic Paris Agreement on climate change, in which 195 sovereign nations agreed on a collaborative path forward to limit future global warming to well below 2°C, and strive for 1.5°C in order to protect the most vulnerable. For this achievement Ms. Figueres has been credited with forging a new brand of collaborative diplomacy, for which she has received multiple awards.

Since then Ms. Figueres has continued to serve her one and only boss, the global atmosphere. She sits on multiple boards and is a founding partner of Global Optimism Ltd., a purpose driven enterprise focused on social and environmental change. She convenes Mission 2020 and co-chairs the Global Covenant of Mayors.

She is a graduate of Swarthmore College and the London School of Economics. She lives in London and has two fantastic daughters.

Fletcher Harper

Fletcher Harper

Fletcher Harper, an Episcopal priest, is Executive Director of GreenFaith, an international interfaith environmental organization. He has developed a range of innovative programs to make GreenFaith a global leader in the religious-environmental movement.

In the past four years, he coordinated the 2015 OurVoices campaign, which mobilized religious support globally for COP 21, led organizing of faith communities for the People’s Climate Marches in NYC and Washington DC, helped lead the faith-based fossil fuel divestment movement, supported the launch of the global Interfaith Rainforest Initiative, and co-founded Shine, a faith-philanthropy-NGO campaign to end energy poverty with renewable energy by 2030. He helps lead GreenFaith’s new local organizing initiative, creating multi-faith GreenFaith Circles in communities globally.

Fletcher accepted GreenFaith’s Many Faith’s, One Earth Award from UN Secretary General Ban Ki-moon in 2009 and was named an Ashoka Fellow in 2011. He is the author of GreenFaith: Mobilizing God’s People to Protect the Earth (Abingdon Press, 2015).

Archbishop Jean-Claude Hollerich *

Mgr Jean-Claude Hollerich is Archbishop of Luxembourg and President of COMECE, the Commission of the Bishops’ Conferences of the European Community. Archbishop Hollerich was born in Luxemburg in 1958 and was ordained priest in 1990. He went to Japan for several years in the mid-1980s and after a period of advanced studies in Europe he returned to the Asian country in 2002, becoming a member of the Jesuit’s Japan Province. Between 2008 and 2011 he was Vice-Rector for the General and Student Affairs at the Sophia University in Tokyo. In 2011, Pope Benedict XVI appointed him as Archbishop of Luxembourg.

He became President of the Conference of European Justice and Peace Commissions in 2014 and President of the Council of Bishops’ Conferences of Europe’s Commission for Youth in 2017. On March 2018 he has been elected president of COMECE, the Commission of the Bishops’ Conferences of the European Union, for a five year term 2018-2023, according to a COMECE press release.

He led the fossil fuels divestment commitment of the Archdiocese of Luxembourg joining in June 2018 the global divestment announcement promoted by the GCCM. He affirmed: “We, the bishops, are increasingly committed to making financial decisions that are in line with our moral values. Divestment is an important way for the Church to show leadership in the context of a changing climate.” He also signed the Chirch leaders’ statement for COP 24, where continental Bishops reiterated their call to “put an end the fossil fuel era.”

Ayesha Imam

Ayesha Imam is a rights and sustainable development activist. She has worked with and for a range of organizations including women’s rights, official aid and UN agencies on women’s rights, gender-sensitive research and programming, democracy, sustainable development and organizational support and training.

Ayesha’s interest in the environment was sparked by a conference at Ahmadu Bello University (Nigeria) on the so-called “Green Revolution” in agriculture in 1982 and co-edited then a critique of the ‘Green Revolution’ in Nigeria. Since then she has been active specifically on environmental issues through: the Women’s Environment and Development Organization (which won a UNEP award during the time she was on the Board), and the Gender CC (women for climate justice – a global network of organizations, experts and activists working for gender equality, women’s rights and climate justice). Ayesha was a member of the Greenpeace International Board for seven years (2006-2013) and is currently the Chair of the International Board (2017 to date).

Ayesha holds that environmental issues are part of social justice and rights issues, and much of her focus has been to bring environment concerns to work in other arenas, and vice versa. In other arenas, Ayesha has been: the founding chief executive of BAOBAB for Women’s Human Rights in Nigeria (which won the John Humphrey Human Rights Award for defense of women’s rights under the Sharia Penal Codes and helped secure acquittals for women and men sentenced to stoning to death); Head of the Culture, Gender and Human Rights Department of UNFPA; activist with the Women Human Rights Defenders International Coalition, the Council for the Development of Economic and Social Research in Africa, the international solidarity network Women Living Under Muslim Laws, the International Council for Human Rights Policy, Africa Action and the African Centre for Democratic Governance; as well as coordinated several global research or capacity-building programmes.

She has lectured and carried out research at universities and research institutes in Nigeria, the U.K., Canada and Senegal. Her work is published widely for activist, policy, and academic uses, and includes books, journal articles, policy briefs and activist manuals.

Stephen M. Kretzmann

Stephen Kretzmann has campaigned for social and environmental justice since first getting involved in anti-apartheid solidarity work as a student. For the last thirty years, he has investigated and exposed environmental and human rights crimes associated with and caused by the global fossil fuel industry. He was an environmental advisor to the late Ken Saro-Wiwa and the Movement for the Survival of the Ogoni People in Nigeria.

Today, Stephen leads a global team of 20 working with frontline communities, civil society, public and private financial institutions, corporations, and international organizations to remove the social license of the fossil fuel industry, to raise the bar for climate leadership, and to shift the politics of the possible towards justice. He founded Oil Change in 2005 to use data, advocacy and organizing to identify and overcome political and economic barriers to the clean energy transition and the phaseout of the fossil fuel industry.

Stephen has authored numerous articles and reports, testified before U.S. Congress and is a regular media commentator on issues of corporate accountability, climate, and the true price of oil. Follow him on Twitter: @Kretzmann. Learn more about Oil Change at

Makoma Lekalakala

Makoma Lekalakala is the Director of Earthlife Africa, a civil society environmental justice and anti-nuclear organisation. She has been active in social movements tackling issues from gender and women’s rights, social, economic and environmental justice issues. In recent years, Lekalakala has focused in targeting environmental corruption.

Her commitment to climate justice in South Africa has led civil society to win the first South African climate change legal case against the government and the reversal of the nuclear deal by SA and the Russian government of which she received the Goldman Environmental Prize for Africa 2018 and SAB Environmentalist of the year 2018. Ms Lekalakala has her roots as a liberation struggle and is strong campaigner for a just and fair society.

Archbishop Thabo Makgoba

The Most Reverend Dr. Thabo Makgoba is the South African Anglican Archbishop of Cape Town. He was made Bishop of Queenstown (Suffragan Bishop of Grahamstown) on 25 May 2002 and became Bishop of Grahamstown in 2004. Until he moved to the Diocese of Grahamstown as bishop suffragan, Makgoba’s ministry had been spent in the Diocese of Johannesburg, first as a curate at the cathedral and then as Wits’ chaplain.

After that he was put in charge of St Alban’s Church and later of Christ the King, Sophiatown. He became Archdeacon of Sophiatown in 1999. He became Archbishop of Cape Town on 31 December 2007, the youngest person ever to be elected to this position. He is a Procter Fellow (2008) from the Episcopal Divinity School in the United States.

He also graduated with a PhD degree from the University of Cape Town in December 2009. He was awarded the Ernest Oppenheimer Memorial Trust Scholarship to study for his doctorate. An Adjunct Professor at GSB(UCT) Allan Gray School for Values.

Bill McKibben

Bill McKibben *

An author and environmentalist who in 2014 was awarded the Right Livelihood Prize, sometimes called the ‘alternative Nobel.’ His 1989 book The End of Nature is regarded as the first book for a general audience about climate change, and has appeared in 24 languages; he’s gone on to write a dozen more books.

He is a founder of, the first planet-wide, grassroots climate change movement, which has organized twenty thousand rallies around the world in every country save North Korea, spearheaded the resistance to the Keystone Pipeline, and launched the fast-growing fossil fuel divestment movement.

The Schumann Distinguished Scholar in Environmental Studies at Middlebury College and a fellow of the American Academy of Arts and Sciences, he was the 2013 winner of the Gandhi Prize and the Thomas Merton Prize, and holds honorary degrees from 18 colleges and universities. Foreign Policy named him to their inaugural list of the world’s 100 most important global thinkers, and the Boston Globe said he was “probably America’s most important environmentalist.”

A former staff writer for the New Yorker, he writes frequently for a wide variety of publications around the world, including the New York Review of Books, National Geographic, and Rolling Stone. He lives in the mountains above Lake Champlain with his wife, the writer Sue Halpern, where he spends as much time as possible outdoors . In 2014, biologists honored him by naming a new species of woodland gnat— Megophthalmidia mckibbeni–in his honor.

Kumi Naidoo

Kumi Naidoo

Kumi Naidoo is a life-long social justice campaigner hailing from South Africa. Born in Durban in 1965, Kumi’s first taste of activism came at age 15 when he organised and took part in an anti-apartheid protest that saw him expelled from his school.

From there he became deeply embedded in activism in his local community and organising mass mobilisations against the apartheid regime. In 1986, at the age of 21, Kumi was charged for violating the state of emergency regulations. He was forced to go underground, before deciding to live in exile in the UK where he stayed until Nelson Mandela was released and liberation movements were unbanned.

As the apartheid regime crumbled, Kumi returned to South Africa in 1990 to work with the African National Congress. There, he took up a cause close to his heart: education, specifically adult literacy campaigns and voter education efforts to empower historically and systematically disenfranchised communities.

Kumi has held multiple leadership roles, but his time as Executive Director of Greenpeace International cemented his reputation as a bold activist who championed civil disobedience, most notably when he was arrested for scaling a Greenlandic oil rig to hand-deliver a petition in protest of drilling in the Arctic in 2011. A year later he occupied a Russian oil rig in the Barents Sea in the Russian Arctic.

Mayor Dan Plato *

Daniel Plato is a South African politician who is the Mayor of Cape Town, after having taken office on 6 November 2018, a position he previously held from May 2009 until June 2011. He previously served as Member of the Western Cape Provincial Legislature and Western Cape Provincial Minister of Community Safety.

Born in Cape Town, Plato was involved in political activities during his high school career. He was a community organiser and played a crucial role in mobilizing residents against the Apartheid government. He was elected a ward councillor in 1996. He served in various positions and internal Democratic Alliance caucus positions during his tenure as Cape Town city councillor. He was elected mayor in 2009, succeeding Helen Zille.

He left office on 1 June 2011 after the Democratic Alliance nominated Patricia de Lille to be the party’s mayoral candidate ahead of the 2011 local government elections. Western Cape Premier Helen Zille reshuffled her cabinet and appointed Plato to the position of Provincial Minister of Community Safety, succeeding Albert Fritz. He was sworn in on June 2011.

In August 2018, he declared himself to be a candidate to replace Patricia de Lille, who announced that she would resign in October 2018. He was selected by the Democratic Alliance in September 2018. In late October 2018, Plato resigned as Provincial Minister of Community Safety and Member of the Western Cape Provincial Parliament and was sworn in as Member of the Cape Town City Council on 1 November 2018. He was elected Mayor of Cape Town on 6 November 2018 and announced his Mayoral Committee on 12 November 2018.

Mary Robinson

Mary Robinson *

Mary Robinson is the Adjunct Professor for Climate Justice in Trinity College Dublin and Chair of The Elders. She served as President of Ireland from 1990-1997 and UN High Commissioner for Human Rights from 1997-2002. She is a member of the Club of Madrid and the recipient of numerous honours and awards including the Presidential Medal of Freedom from the President of the United States Barack Obama.

She sits on the advisory board of Sustainable Energy For All (SE4All) and is a member of the Advisory Council of the European Climate Foundation and of the Lead Group of the Scaling Up Nutrition (SUN) Movement. Between 2013 and 2016 Mary served as the UN Secretary General’s Special Envoy in three roles; first for the Great Lakes region of Africa, then on Climate Change and most recently as his Special Envoy on El Niño and Climate.

A former President of the International Commission of Jurists and former chair of the Council of Women World Leaders she was President and founder of Realizing Rights: The Ethical Globalization Initiative from 2002-2010 and served as Honorary President of Oxfam International from 2002-2012.

Mary Robinson serves as Patron of the Board of the Institute of Human Rights and Business, is an Ambassador for The B Team, in addition to being a board member of several organisations including the Mo Ibrahim Foundation and the Aurora Foundation. She was Chancellor of the University of Dublin from 1998 to 2019. Mary’s memoir, ‘Everybody Matters’ was published in September 2012 and her book, ‘Climate Justice – Hope, Resilience and the Fight for a Sustainable Future’ was published in September 2018.

Mark Watts

Mark Watts *

Mark has served as Executive Director of C40 since December 2013, during which time the organisation has grown from 63 to 96 of world’s greatest cities. Mark is proud to head a fast-growing team of 150 staff in supporting bold, collaborative mayors to demonstrate that tackling climate change will deliver economically stronger and more equitable cities.

Prior to joining C40 Mark was Director at pioneering engineering and design firm, Arup, and before that was a senior adviser to the Mayor of London, in which role the London Evening Standard described him as “the intellectual force behind Ken Livingstone’s drive to make London a leading light of the battle against global warming.” He reports to C40 Chairperson and Mayor of Paris, Anne Hidalgo, and C40 Board President, Mayor Michael R. Bloomberg. He believes that work should be fun, but that there is always time for music, narrowboats, and places you can get to by bicycle.

* These global ambassadors will not be present in person at the Summit.