TOP 10 Most-Read Thought Leaders in Climate Change

Discover also our 2026 Rankings of the Most Read Thought Leaders in Business Impact, Carbon, Circularity, Energy, Energy Transition, Environmental Sustainability, ESG, Ethical Governance, Green Tech, Nature, Renewables, Social Responsibility, Sustainable AI, Sustainable Business, Sustainable Finance, Sustainable Lifestyle, and Overall. Explore how this year's leaders compare to the most influential Climate Change voices of last year!

illuminem is proud to present the most-read Thought Leaders in Climate Change globally, as recognised by illuminem's ever growing community of 700,000+ readers.

2025 was the third warmest year on record and the first three-year period to average above 1.5°C, the threshold the Paris Agreement was designed to protect. The LA wildfires caused over $60 billion in damage, the costliest in history. A billion-dollar weather disaster struck the US every ten days on average. And yet the world's largest historical emitter withdrew from the Paris Agreement, scrapped its disaster tracking infrastructure, and moved to revive coal. The gap between what the science was saying and what politics was doing had rarely been wider or more consequential.

Against that backdrop, the voices on this list approached the crisis from strikingly different vantage points: Johan Rockström from the architecture of planetary systems, Robert Muggah and Felix Ekardt from the intersection of climate and security.

What distinguished Christiana Figueres, Laurence Tubiana, and Gail Bradbrook in that conversation was their ability to shape consensus in a deeply polarised debate. As co-authors of an open letter that brought together an unprecedented coalition of scientists, activists, and CEOs demanding COP30 codify information integrity, they demonstrated why they have been such formative voices in global climate governance. In a year when that governance was breaking down, their insistence that climate action requires a shared commitment to truth came at a critical time.

Drawn from over 2,500 thought leaders publishing on illuminem Voices, the ranking below reflects the voices that shaped how the climate change conversation evolved in 2025.

1️⃣ ex aequo Christiana Figueres - Fmr. Executive Secretary of the United Nations Framework Convention on Climate Change
Country: Costa Rica 🇨🇷
Most-Read Thought Piece: Open letter: Climate action requires truth – COP30 must codify information integrity
Profile: Christiana Figueres is the fmr. Executive Secretary of the United Nations Framework Convention on Climate Change (UNFCCC). She is now the Founding Partner of Global Optimism, co-presenter of climate podcast Outrage + Optimism, and co-author of The Future We Choose: The Stubborn Optimist's Guide to the Climate Crisis. As a globally recognised climate leader who led the diplomatic efforts behind the 2015 Paris Agreement, she is also a member of the B Team and Chair of The Earthshot Prize Foundation.

1️⃣ ex aequo Laurence Tubiana - CEO of the European Climate Foundation
Country: France 🇫🇷
Most-Read Thought Piece: Open letter: Climate action requires truth – COP30 must codify information integrity
Profile: Laurence Tubiana is the Chief Executive Officer of the European Climate Foundation and one of the key architects of the Paris Agreement. As France's Climate Change Ambassador for COP21, she helped steer the landmark 2015 accord. She previously founded and directed the Institute for Sustainable Development and International Relations (IDDRI) and served as Chair of the French Development Agency (AFD). A professor at Sciences Po, she continues to shape global climate policy and sustainable development.

1️⃣ ex aequo Gail Bradbrook - Co-Founder of Extinction Rebellion
Country: United Kingdom 🇬🇧
Most-Read Thought Piece: Open letter: Climate action requires truth – COP30 must codify information integrity
Profile: Gail Bradbrook is the co-founder of the prominent activist group Extinction Rebellion. She earned her PhD in molecular biophysics at the University of Manchester and completed post-doctoral work in India and France. In 2018 she helped launch Extinction Rebellion, a global movement for radical non-violent civil disobedience to confront climate breakdown and ecological collapse.

2️⃣ Wil Burns - Founding Co-Director of the Institute for Responsible Carbon Removal at American University
Country: United States 🇺🇸
Most-Read Thought Piece: The EU's climate law amendment: can it help carbon dioxide removal?
Profile: Dr. Wil Burns serves as the Founding Co-Director of the Institute for Responsible Carbon Removal at American University and is a Professor in the School of International Service. Wil has held several teaching positions in renowned universities, including Johns Hopkins University, where he was the founding Director of the Energy Policy & Climate program, the University of California-Berkeley, Stanford University, and the University of Chicago. His primary research focuses on carbon dioxide removal approaches to combat climate change, solar geoengineering, and the loss and damage provisions of the Paris Agreement.

3️⃣ ex aequo Sandrine Dixson-Decleve - Fmr. President of the Club of Rome
Country: Belgium 🇧🇪
Most-Read Thought Piece: COP30 must protect the stability of Earth's two richest biomes: the Amazon rainforest and the coral reefs
Profile: Sandrine Dixson-Decleve is the fmr. President of the Club of Rome, chair of Earth4All, and founder of System Transformation Hub. She is also a Cambridge Institute for Sustainability Leadership Senior Associate and faculty member. She serves on multiple advisory and non-executive boards, including the Climate Governance Commission, BMW, and Imperial College London.

3️⃣ ex aequo Johan Rockström - Director of the Potsdam Institute for Climate Impact Research
Country: Sweden 🇸🇪
Most-Read Thought Piece: COP30 must protect the stability of Earth's two richest biomes: the Amazon rainforest and the coral reefs
Profile: Johan Rockström is the Director of the Potsdam Institute for Climate Impact Research and Professor in Earth System Science at the University of Potsdam. As a leading voice on global sustainability issues, he co-developed the Planetary Boundaries framework and advises governments, businesses, and international institutions on resilience and climate policy. His work bridges Earth system science and actionable pathways for a safe and just future.

3️⃣ ex aequo Robert Muggah - Co-Founder of the SecDev Group and Igarape Institute
Country: Brazil 🇧🇷
Most-Read Thought Piece: COP30 must protect the stability of Earth's two richest biomes: the Amazon rainforest and the coral reefs
Profile: Robert Muggah is the co-founder of the SecDev Group and Igarape Institute. An expert in geopolitics, international security, the future of cities, green technology and cybersecurity, he advises international organizations, companies, philanthropies and non-profits. He received a DPhil from the University of Oxford.

4️⃣ Charles Hinckley - Managing Partner at CC Hinckley Co.
Country: United States 🇺🇸
Most-Read Thought Piece: Combat climate and renewable energy – polite dinner topics?
Profile: Charles Hinckley is currently the Managing Partner at CC Hinckley Co. a firm he founded in 1998; most recently, he has been the interim COO of a utility-scale solar power development company, Co-Head of the New York office of investment bank Marathon Capital, the CEO of AWCC Capital, and the CEO of Noble Environmental Power.

5️⃣ Timothy Shanahan - Associate Professor of Geological Sciences at The University of Texas at Austin
Country: United States 🇺🇸
Most-Read Thought Piece: Climate models reveal how human activity may be locking the Southwest into permanent drought
Profile: Tim Shanahan is Associate Professor of Geological Sciences and Director of the Environmental Science Program at The University of Texas at Austin, where he researches climate change and variability, focusing on their impacts on landscapes, ecosystems, and hydrogeology. His work integrates geochemical analyses of past climates with model simulations to identify the causes of historical climate shifts and assess implications for sustainability and water resources.

6️⃣ Felix Ekardt - Head of the Research Unit Sustainability and Climate Policy
Country: Germany 🇩🇪
Most-Read Thought Piece: Conservation more important than climate protection
Profile: Felix Ekardt is Head of the Research Unit Sustainability and Climate Policy in Leipzig and a professor at the University of Rostock. He is widely regarded as one of the world's leading experts in climate law and constitutional climate rights. Since 1996, he has contributed to more than 500 scientific publications and has initiated several key legal actions, including the landmark climate lawsuit before the German Federal Constitutional Court. Felix is also the author of the book Sustainability: Transformation, Governance, Ethics, Law.

7️⃣ Simon Heppner - Chief Sustainability Officer at Ecologi
Country: United Kingdom 🇬🇧
Most-Read Thought Piece: What COP30 actually delivered — and does it even matter?
Profile: Simon Heppner is the Chief Sustainability Officer at Ecologi, a certified B Corp. He previously founded Net Zero Now and also serves as a Non-Executive Director at Farm Wilder. Simon studied Natural Resource Economics at The University of Manchester.

8️⃣ Roger Abravanel - Director Emeritus of McKinsey
Country: Israel 🇮🇱
Most-Read Thought Piece: Greta: from green icon to enemy of the planet
Profile: Roger Abravanel is Director Emeritus of McKinsey where he led global projects for 35 years. Since his retirement he has been a member of boards of companies listed on NYSE, LSE, NASDAQ, Milan and Tel Aviv stock exchanges. He is also advisor to PE and VC funds and a high tech investor. Author of six best-selling books including Meritocracy and Aristocracy 2.0, his latest work co-authored with Luca D'Agnese addresses the climate crisis: Climate Beyond Hypocrisy. He is also a member of the Advisory Board of Politecnico di Milano and was selected by INSEAD as "one of the 50 who changed the world" among 40,000 alumni of the school.

9️⃣ Ashish Kothari - Founder of Kalpavriksh
Country: India 🇮🇳
Most-Read Thought Piece: The world's highest court plugs for climate action
Profile: Ashish Kothari is a globally recognized environmentalist who has spent over 40 years tackling key environmental and climate change-related issues. He is the Founder of Kalpavriksh, a non-profit organization working on environmental and social issues at local, national and global levels. He served as a member of the Steering Committees of the World Commission on Protected Areas (WCPA) and as a coordinator for India's National Biodiversity Strategy & Action Plan. Ashish has authored and edited 30+ books and 300+ articles.

🔟 Carl Pope - Fmr. Chairman and Executive Director of Sierra Club
Country: United States 🇺🇸
Most-Read Thought Piece: Environmentalists like me got something terribly wrong about climate change
Profile: Carl Pope is the fmr. Chairman and Executive Director of the leading US conservation NGO, Sierra Club. He currently serves as Senior Climate Advisor to Michael Bloomberg and is Principal at Inside Straight Strategies, focusing on the intersection of sustainability and economic development. He has also founded and led initiatives including the Blue-Green Alliance and America Votes, bridging environmental and labour coalitions.

Congratulations to our most-read thought leaders of the last year. In a time when the sustainability conversation was pulled in every direction at once, the voices on this list helped move it forward with clarity and intellect. We are proud to amplify their voices, and look forward to what comes next.

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