Fiduciary duty requires institutional investors to consider material risks, including climate-related financial impacts, in investment decisions. Major asset owners including CalPERS, the UK Pensions Regulator, and the EU have clarified that climate risk analysis is consistent with—and often mandated by—fiduciary obligations to beneficiaries.
Fiduciary duty requires institutional investors to consider material risks, including climate-related financial impacts, in investment decisions. Major asset owners including CalPERS, the UK Pensions Regulator, and the EU have clarified that climate risk analysis is consistent with—and often mandated by—fiduciary obligations to beneficiaries. Yet the practical application remains contested: climate risk is acknowledged as material, but how deeply to integrate it, which sectors to exclude or engage, and how to balance long-term resilience against near-term return expectations depend on liability structure, time horizon, regulatory jurisdiction, and the quality of available data.
This article examines the legal foundations of fiduciary duty as they relate to climate risk, the emerging regulatory consensus, and how leading institutional investors are operationalizing these obligations in portfolio construction and governance.
What does fiduciary duty require, legally?
Fiduciary duty is the legal obligation of a trustee, pension fund, or investment manager to act in the best interests of beneficiaries. It has three core pillars: prudence (reasonable care in decision-making), loyalty (acting for beneficiaries, not fund sponsors or asset managers), and compliance with investment mandates.
For decades, the prudence standard was interpreted narrowly: analyze financial metrics (earnings, cash flow, valuation multiples) and disregard non-financial factors. Climate change disrupted this frame. The argument, now dominant in developed markets, runs as follows: climate impacts are financial. They affect crop yields, insurance costs, real estate values, commodity prices, stranded assets, and debt serviceability. Failing to analyze them is imprudent, not prudent.
The UK Pensions Regulator codified this in 2021, requiring trustees to assess climate as a financial risk, not a values-based choice. The regulator found that 70% of surveyed schemes had not fully integrated climate risk into their governance frameworks, and issued binding guidance. CalPERS, the largest U.S. public pension fund ($440 billion AUM), has embedded climate analysis in its investment decisions since 2015, treating it as core to risk management rather than ESG overlay.
The U.S. Department of Labor revised its guidance in February 2023 to clarify that ESG factors—including climate—can be considered in retirement plan investing if they are "consistent with the plan's investment objectives and strategy" and "analyzed for their impact on risk-adjusted returns." The language is careful: not mandated, but explicitly permitted and, if material, prudent to analyze.
The EU has gone furthest. The Institutional Investors Directive (2021) and subsequent delegated acts require European asset owners to disclose how they integrate sustainability risk into their investment processes and governance. For many European pension schemes and insurance companies, this is now a legal floor, not an optional exercise.
How do institutional investors operationalize climate risk within fiduciary duty?
The regulatory consensus—that climate risk is material and must be analyzed—has created a practical dilemma: climate risk is harder to measure than traditional financial risk. Future physical impacts are uncertain, transition pathways vary by sector and jurisdiction, and most climate data is backward-looking or scenario-dependent.
Leading asset owners have adopted a framework-based approach:
Scenario analysis and stress testing. CalPERS, the California State Teachers' Retirement System (CalSTRS, $313 billion AUM), and the European Central Bank's stress tests all use climate scenarios (aligned with the Task Force on Climate-related Financial Disclosures standard) to model portfolio exposures under different warming pathways (1.5°C, 2°C, business-as-usual, etc.). These are not predictions but structured tests of how portfolios perform under different assumptions about policy, technology adoption, and physical risk.
Sector-level engagement and exclusion. CalPERS has excluded coal thermal power producers since 2015, having concluded that the financial risks outweighed return potential and that engagement (with utilities transitioning away from coal) offered better outcomes for beneficiaries. This was framed as a financial decision, not a divestment campaign. The UK Pensions Regulator has not mandated exclusion but expects schemes to document why certain exposures are or are not held.
Board-level accountability. Major asset owners now include climate risk assessment in investment committee papers and annual reporting to boards. The Norwegian Government Pension Fund Global ($1.3 trillion AUM) appointed a chief investment officer tasked partly with climate risk integration and has divested from oil and gas exploration (2019–2023) and later from some thermal coal producers, again framed as financial prudence after scenario analysis.
Third-party climate risk tools. Funds rely on climate data providers (Carbon Trust, Trucost, S&P Global, Bloomberg) to assess portfolio carbon intensity, climate exposure, and transition risk. These tools are imperfect—they depend on company disclosure, which is inconsistent—but they enable standardized comparisons across holdings and sectors.
What is the relationship between fiduciary duty and divestment?
This remains contentious. Divestment—the sale of fossil fuel or high-emitting assets—is legally defensible under fiduciary duty if it improves risk-adjusted returns or if engagement has demonstrably failed. It is not mandated by fiduciary duty.
The distinction matters. Some institutions (e.g., Norwegian Government Pension Fund, which divested from oil and gas exploration and some coal producers) argue that financial analysis of long-term stranded asset risk justifies divestment. Others (e.g., many U.S. public pension schemes) prefer engagement with energy transition, arguing it preserves returns and leverage with companies. The legal standard does not prescribe one approach; it requires evidence of prudent process.
The U.S. Department of Labor's 2023 guidance has been interpreted by some as discouraging ESG-first divestment (i.e., divesting for values), but the guidance explicitly permits divestment if it improves risk-adjusted returns. The ambiguity reflects real uncertainty: are fossil fuel equities in secular decline, or will transition technologies be absorbed by existing energy firms? The answer varies by company and time horizon, which is why fund-by-fund analysis is required, not categorical rules.
How do liability structure and time horizon shape climate risk frameworks?
This is often overlooked. A pension scheme with a 30-year duration (average age of beneficiaries weighted by liability) faces different climate exposures than an endowment with a 100-year time horizon, which faces different risks than a sovereign wealth fund.
Pension schemes with short-duration liabilities (e.g., mature schemes paying mostly to retirees) are exposed to near-term transition risks: energy price shocks, stranded assets in infrastructure portfolios, and credit downgrades in fossil fuel-exposed sectors. Those with long-duration liabilities (e.g., young schemes, endowments) are more exposed to physical risks: drought-driven agricultural losses, climate migration affecting real estate, and long-tail tail risks in inflation and growth.
See The Discount Rate and Pension Liabilities, Explained for how liability structure interacts with return assumptions and funding adequacy. Lower discount rates (reflecting declining long-term bond yields) increase the sensitivity of pension finances to tail risks, including climate-driven economic disruption.
Sovereign wealth funds, unconstrained by defined benefit liabilities, can afford longer time horizons and higher volatility tolerance. The Abu Dhabi Investment Authority (ADIA, estimated $150+ billion AUM) and the Saudi Public Investment Fund (PIF) have both integrated climate and energy transition into long-term diversification strategies. See Abu Dhabi's Sovereign Wealth Ecosystem: ADIA, Mubadala, ADQ, and MGX for detail on how institutional structure shapes investment governance.
What is the regulatory variation across jurisdictions?
Fiduciary duty is largely national law, so regulatory expectations vary:
United Kingdom. The Pensions Regulator has been most prescriptive, requiring climate risk assessment as a financial risk, disclosure under the TCFD framework, and scenario analysis. UK defined benefit schemes face binding guidance; defined contribution schemes face softer requirements but increasing pressure.
European Union. The Institutional Investors Directive and subsequent regulations require transparency on how sustainability risks (including climate) are integrated into investment strategies. Compliance is measured through annual disclosures and supervisory review.
United States. No federal mandate exists; state pension fund boards (CalPERS, CalSTRS, teacher pension funds in major states) have voluntarily integrated climate analysis. The SEC has proposed climate disclosure rules for companies but has not mandated climate integration for asset owners. The Department of Labor's 2023 guidance is permissive, not prescriptive.
Australia and Canada. Australia's superannuation regulator (APRA, Australian Prudential Regulation Authority) expects trustees to assess climate risk; Canada has no explicit mandate but leading funds (Canada Pension Plan Investment Board, Ontario Teachers' Pension Plan) practice scenario analysis voluntarily.
How should institutional investors reconcile climate risk with return objectives?
This is the practical crux. Fiduciary duty obligates funds to maximize returns for beneficiaries over the appropriate time horizon. If climate risk is material to returns, it must be analyzed. But analyzing climate risk does not dictate a single portfolio strategy.
Three approaches are credible:
Transition investing. Allocate capital to companies and sectors in the energy transition (renewable energy, electric vehicles, efficiency, carbon capture). Framed as capturing growth and avoiding stranded assets.
Engagement and stewardship. Hold fossil fuel and high-emitting exposures while actively engaging with management on transition planning, lobbying on climate policy, and joining industry collaborative initiatives (e.g., Climate Action 100+). Framed as preserving returns while incentivizing change.
Selective exclusion. Exclude sectors with highest climate risk (thermal coal, oil sands, certain utilities) after determining that engagement failed or that exclusion improves risk-adjusted returns. Framed as financial prudence.
Each can be defensible under fiduciary duty if the fund documents why it was chosen and how it aligns with beneficiary interests. The legal requirement is process and evidence, not outcome.
What gaps remain in climate risk integration?
Despite regulatory momentum, several gaps persist:
Data quality. Corporate climate disclosures remain inconsistent. Most climate data providers rely on company-reported emissions, which are incomplete (especially Scope 3, or supply chain emissions). Asset-level physical risk data is improving but still patchy outside developed markets.
Transition risk pricing. Markets are not consistently pricing in transition risk (stranded assets, energy price shifts, policy changes). This creates an opportunity for active investors but makes it harder for passive funds to rely on market prices for climate risk assessment.
Tail risk and systemic risk. Most climate models focus on company or sector impact. Fewer frameworks analyze systemic climate risk—how widespread energy transition, agricultural disruption, or physical risk could cascade through financial markets and affect all asset classes simultaneously. See Climate Change as a Systemic Risk for Universal Owners for detail.
Liability structure mismatch. Many pension schemes with long-duration liabilities have not fully adjusted return assumptions or risk budgets to account for climate-driven downside scenarios. If long-term growth is lower due to climate disruption, liability-driven investment strategies may be undershooting.
Implications for Long-Term Capital Allocators
Institutional investors face a clarified legal landscape: fiduciary duty does not forbid climate risk analysis; it increasingly requires it. The material question is not whether to consider climate risk, but how deeply and at what cost to return potential.
Key decisions ahead:
Updating return assumptions. If climate impacts reduce long-term GDP growth or increase inflation volatility, equity and bond return expectations may need downward revision. This cascades into asset allocation and liability funding assessments.
Building climate expertise in-house. Reliance on third-party climate data providers is necessary but insufficient. Funds need internal capability to interpret scenarios, challenge vendor assumptions, and integrate climate risk into equity research and sector allocation.
Standardizing governance. Boards must document climate risk frameworks, assign accountability, and link investment decisions to scenario analysis. Vague commitments to "sustainable investing" do not meet fiduciary standards; specific, documented processes do.
Engaging policy makers. Climate risk management at the fund level cannot succeed if policy uncertainty remains extreme. Leading asset owners (CalPERS, PPI, large European pension schemes) are increasingly vocal about the need for clear long-term climate policy to reduce investment uncertainty.
See How Should Long-Term Investors Think About Climate Risk? for a deeper dive into portfolio construction frameworks that balance climate resilience with return objectives.
The regulatory case for climate risk integration is now settled in most developed markets. The strategic case—how to integrate it profitably—remains open, and that is where competitive advantage and fiduciary excellence will be earned.
What changed in 2025-26?
The past year provided harder evidence that climate-risk management is being operationalised through ownership, not just policy statements. Norges Bank Investment Management, which runs Norway's roughly $2 trillion sovereign wealth fund, reported that under its 2025 climate action plan the share of portfolio companies' emissions covered by science-based net-zero targets rose from 57% to 76%, and the proportion of companies with such targets more than doubled. It backed dialogue with escalation, voting against directors at 69 companies for inadequate climate-risk management and filing seven shareholder proposals. CalPERS continued to withhold votes from committee members overseeing weak climate governance at its highest-emitting holdings. Collaborative pressure scaled in parallel: Climate Action 100+ grew to more than 700 signatories representing over $68 trillion in assets.
On the regulatory side, the European framework moved further toward treating climate risk as financial risk that prudent investors must assess. IORP II already embeds environmental, social and governance factors in pension-fund risk management, and the 2025 review of the Shareholder Rights Directive II floated an EU-wide shareholder right to vote on "say on climate, nature or sustainability." The academic evidence also firmed up the engagement-versus-divestment question in favour of engagement backed by a credible exit threat. For how that evidence translates into strategy, see our explainer on engagement vs divestment: which actually works and what shareholder engagement is. The settled conclusion stands: ignoring material climate risk is increasingly inconsistent with fiduciary duty, and the open question is how to integrate it profitably.