TOP 10 Most-Read Thought Leaders in Environmental Sustainability

Discover also our 2026 Rankings of the Most Read Thought Leaders in Business Impact, Carbon, Circularity, Climate Change, Energy, Energy Transition, 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 Environmental Sustainability voices of last year!

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

Environmental sustainability in 2025 was a study in contradiction. The High Seas Treaty was ratified, bringing the first legally binding framework for marine biodiversity into force after twenty years of negotiations. The International Court of Justice issued an advisory opinion affirming a clean and healthy environment as a human right. COP30, held inside the Amazon itself, kept nature at the centre of the global agenda.

Yet at the same time, scientists confirmed that coral reefs had crossed the first verified Earth system tipping point: a threshold, by definition, you cannot uncross. The Amazon endured its worst fire season in two decades. Seven of the nine planetary boundaries were breached.

Beneath these contradictions, a quieter shift of agency was underway: the question of who leads the environmental transition, who bears its costs, and whose frameworks govern it was being answered differently in 2025 than it had been a decade before.

What distinguished Elena Morettini in that conversation was her ability to trace the deeper architecture of sustainability leadership as it evolved across sectors and geographies. As Global Head of Sustainable Business at Globant, a digital native multinational, she has had to translate sustainability from policy to practice in contexts ranging from AI ethics to digital sobriety. Her most-read piece made the case that building a better world requires a molecule-level focus on the materials and processes that constitute it, a perspective that cut through a year of macro-level debate with precision. 

Joining her on the list, Erik Solheim argues that the locus of climate leadership has decisively shifted to the Global South, Giulio Boccaletti uses 25 years of satellite data to identify the real driver of forest loss, and Hélène Valade makes the case that environmental sovereignty and economic sovereignty are, at their core, the same fight.

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

1️⃣ Elena Morettini - Global Head of Sustainable Business at Globant
Country: Argentina 🇦🇷
Most-Read Thought Piece: Building a better world, one molecule at a time
Profile: Elena Morettini is the Global Head of sustainable business of Globant, a native digital multinational company, and Co-Founder of BecauseEnergyMatters. She has previously held key managerial positions in renowned international companies such as Shell, Repsol YPF, Badley Ashton, and Fugro GeoConsulting. Elena founded the first Diversity and Inclusion Committee for Oil and Gas in the Latin America region.

 2️⃣ Erik Solheim - Fmr. Norwegian Minister of Environment
Country: Norway 🇳🇴
Most-Read Thought Piece: The top climate leaders are now in the Global South
Profile: Erik Solheim is a well known global leader on environment and development. He served as Norwegian Minister of Environment and International Development from 2005 to 2012. Erik has been chair of the OECD Development Assistance Committee as well as Executive Director of the United Nations Environment Program. He's now working for Global Renewables Alliance (GRA) where he's a Board Member of International Hydropower Association as well as adviser to the Global Wind Energy Council as well as the Global Solar Council. He also contributes his expertise to the development of illuminem's Data Hub™, helping shape its insights on sustainability, and he is a member of the illuminem Leaders Cohort.

 3️⃣ Giulio Boccaletti - Scientific Director of the Centro Euro Mediterraneo sui Cambiamenti Climatici Foundation
Country: Italy 🇮🇹
Most-Read Thought Piece: Exclusive: 25 years of data reveal the real driver of forest carbon loss
Profile: Giulio Boccaletti is the fmr. Chief Strategy Officer and Global Managing Director for Water at The Nature Conservancy and a fmr. Partner at McKinsey & Company. He is the Scientific Director of the Centro Euro Mediterraneo sui Cambiamenti Climatici Foundation, an institution dedicated to advancing climate change science and sustainability solutions. Giulio is also the co-founder of Chloris Geospatial, a venture-backed company that focuses on measuring nature's contribution to the global economy through satellite-based data. He is the author of acclaimed works including Il Futuro della Natura and Water: A Biography, and an Executive Producer for the PBS/BBC series The Future of Nature.

4️⃣ Hans-Otto Pörtner - Professor at the Alfred Wegener Institute for Polar and Marine Research
Country: Germany 🇩🇪
Most-Read Thought Piece: Conservative climate protection
Profile: Hans Pörtner is a professor at the Alfred Wegener Institute for Polar and Marine Research (AWI) and a section head in Integrative Ecophysiology. He is also a Heisenberg fellow with the Deutsche Forschungsgemeinschaft (DFG). With extensive expertise in the effects of climate warming, ocean acidification, and hypoxia on marine ecosystems, his research explores the physiological and molecular mechanisms that limit tolerance in marine animals. He has contributed significantly to understanding the role of climate oscillations in evolutionary history. Hans also serves as a co-chair for Working Group 2 of the IPCC's Sixth Assessment Report, focusing on impacts and adaptation.

5️⃣ Jennifer Morris - CEO of The Nature Conservancy
Country: United States 🇺🇸
Most-Read Thought Piece: Sustainability leaders urge ISSB to agree to introduce dedicated nature standard
Profile: Jennifer Morris is the CEO of The Nature Conservancy, leading a global team in over 80 countries to address the climate emergency and biodiversity loss. Previously, she served for over 20 years at Conservation International, driving impact finance and organisational growth. Jennifer serves on global advisory boards, including Norges Bank Investment Management's Climate Advisory Board and Nestlé's Creating Shared Value Advisory Council. She holds a Master's in International Affairs from Columbia University.

 6️⃣ Harini Nagendra - Professor of Sustainability at Azim Premji University
Country: India 🇮🇳
Most-Read Thought Piece: The weight of humanity presses down on the earth
Profile: Harini Nagendra is a Professor of Sustainability at Azim Premji University in Bangalore, India, and a globally recognised ecologist. Her work integrates satellite remote sensing, biodiversity field studies, and institutional analysis to explore the socio-ecological sustainability of forests and cities in South Asia. She is a Lead Author for the 5th IPCC Report and has over 150 scientific publications.

7️⃣ Giulia Michieli - Writer and Activist
Country: Italy 🇮🇹
Most-Read Thought Piece: Elon Musk: a potential trouble-maker for Europe's environmental future
Profile: Giulia Michieli is a multilingual writer, policy analyst and activist with over a decade of international experience across diplomacy, technology, and public service. Giulia has worked with organizations including the United Nations, Inter-American Development Bank, Google, and Valentino. She holds a B.A. an M.P.A. from Columbia University.

8️⃣ James Balzer - Climate and Sustainability Policy Practitioner
Country: Australia 🇦🇺
Most-Read Thought Piece: What Samoa can teach the world about non-economic loss and damage
Profile: James Balzer is an Australian climate and sustainability policy practitioner, with experience in the Australian Federal Government and the New South Wales Government. He has experience in climate and sustainability policy across think tanks, NGOs and social enterprises in Europe, Australia and Southeast Asia.

9️⃣ Jane Marsh - Editor-in-Chief at Environment.co
Country: United States 🇺🇸
Most-Read Thought Piece: From labs to landfills: pharma's role in climate and environmental crisis
Profile: Jane Marsh is the Editor-in-Chief at Environment.co, where she focuses on environmental science, sustainability, and policy. With experience in editorial leadership, she has contributed to publications such as BOSS Magazine, Energy Central, and Manufacturing.net. She studied at the University of South Africa and has contributed to a range of projects exploring energy, agriculture, and sustainable living.

🔟 Hélène Valade - Environment Development Director at LVMH Group
Country: France 🇫🇷
Most-Read Thought Piece: Sovereignty and sustainability: same fight
Profile: Hélène Valade is the Environment Development Director at LVMH Group, where she leads the company's sustainability and environmental initiatives. She is also the President of the Observatoire de la Responsabilité Sociétale des Entreprises (RSE), advocating for corporate social responsibility. With extensive experience in the environmental sector, Hélène has held prominent roles, including as the Director of Sustainable Development at SUEZ and President of the RSE Platform at France Stratégie. She is a board member of the CNRS and ADEME, playing a key role in shaping policies for environmental sustainability.

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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