5 Principles Every Fiduciary Needs for Climate Risk with Maurits Dolmans

Maurits Dolmans, Senior Counsel at Cleary Gottlieb Steen & Hamilton and co-author of Sustainable Fiduciary Duty: How Fiduciary Duties Can Be a Key to Escaping the Climate Prisoner's Dilemma (Net Zero Lawyers Alliance, November 2025), joins Georges Dyer on his own behalf to make a precise legal and economic argument: existing fiduciary law already requires institutional investors to address systemic climate risk, and he lays out five concrete principles for how to do it. No new legislation required. For CIOs, pension trustees, endowment leaders, asset managers, and their legal counsel, this conversation reframes the entire climate-and-capital debate as a question of legal duty and long-term financial obligation, not values.

Key themes:

• The Climate Prisoner's Dilemma: Why rational actors keep financing high-emission projects against their own long-term interest, and why fiduciary duties, applied consistently, are the coordination mechanism that breaks the cycle without requiring new regulation or bilateral trust
• The Economic Evidence: Rebonato's finding of 40% asset devaluation under business-as-usual, the UK Institute and Faculty of Actuaries' Planetary Solvency Report projecting 30–50% GDP loss, and why this loss, unlike 2008 or Covid, would be permanent
• 5 Principles for Action: Avoiding new unabated fossil fuel finance, internalizing the social cost of carbon in ROI assessments, pursuing transition investment opportunities, active stewardship of investee companies, and advocating for aligned regulation, each grounded in existing fiduciary law
• Case Law & What's Coming: What Spence v. American Airlines, McRitchie v. Zuckerberg, and ClientEarth v. Shell actually says beneath the surface, and why Hirji v. CPPIB (Canada) and Kvek/ClientEarth v. Cushman & Wakefield (Washington State) are the cases to watch next.

This episode is part of IEN's ongoing series on fiduciary duty and system-level investing.

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Resources References:

• Sustainable Fiduciary Duty — Net Zero Lawyers Alliance (2025) → https://www.netzerolawyers.com/publications/sustainable-fiduciary-duties-for-investors → Full PDF: https://cdn.prod.website-files.com/65bb9ebee081d228a8003b56/690cb02c2d3dfd4b5c3fabca_Sustainable%20Fiduciary%20Duty%20-%20FINAL%20(6%20November%202025)%20(Compressed%20-%20Guru).pdf

• Moving Beyond Modern Portfolio Theory: Investing That Matters — Jon Lukomnik & James Hawley → https://www.routledge.com/Moving-Beyond-Modern-Portfolio-Theory-Investing-That-Matters/Lukomnik-Hawley/p/book/9780367760823
• How to Think About Climate Change — Riccardo Rebonato (Cambridge University Press) → https://www.cambridge.org/core/books/how-to-think-about-climate-change/6F6AAB54523738CC7CF83B0EEFECD3A2
• Making Sense of Chaos: A Better Economics for a Better World — J. Doyne Farmer → https://yalebooks.yale.edu/book/9780300283327/making-sense-of-chaos/

• Planetary Solvency: Finding Our Balance with Nature — Institute and Faculty of Actuaries & University of Exeter (January 2025) → https://actuaries.org.uk/news-and-media-releases/news-articles/2025/jan/16-jan-25-planetary-solvency-finding-our-balance-with-nature/
• Recalibrating Climate Risk — Carbon Tracker & University of Exeter (February 2026) → https://carbontracker.org/reports/recalibrating-climate-risk/

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General Timestamps:

 

00:00 Introduction & The Net Zero Lawyers Alliance Report

02:21 The Climate Prisoner's Dilemma Explained

05:38 How Fiduciary Duties Solve the Collective Action Problem

07:22 The Three Core Fiduciary Duties: Purpose, Loyalty, and Care

09:43 The Economic Evidence: 40% Asset Devaluation & Permanent GDP Loss

13:54 Climate Tipping Points Investors Are Not Pricing In

16:20 Why Existing Law Already Applies — No New Legislation Required

18:56 Principle 1: Avoid Finance for New Unabated High-Emission Projects

23:12 Principle 2: Internalize Climate Risk in ROI Assessments

24:49 Principle 3: Pursue Viable Impact Investments in the Transition

27:09 Principle 4: Active Sustainability Stewardship

29:04 Principle 5: Advocate for Aligned Regulation and Policy

31:14 Case Law Deep Dive: Spence, McRitchie, ClientEarth v. Shell

36:46 How to Make the Case to Skeptical Trustees and Boards

43:48 Addressing the Main Objections to Sustainable Fiduciary Theory

52:34 Pending Cases and the Five-Year Outlook for Fiduciary Law

56:45 Rapid Fire: One Action, Recommended Reading & Vision for Finance