The compatibility of Environmental, Social and Governance (ESG) risk management with the investment management requirements under the investors’ fiduciary duties (FD) figures among the key questions in today’s context of a rapid growth of sustainable investment strategies. Despite some legal developments, namely, in Europe, investors still have no clear answer to this question, which leaves them inert in the face of these new, unconventional types of risk. In our research, we explore the recent advancements in the EU and the US legal practice with the objective to establish to what extent the FD actually requires investors to consider ESG risks in their investment management decisions. Through analysis, we define a theoretical decision-making pattern for ESG risk management set by the current FD law as applied to investors and identify: 1) ESG risk materiality and 2) the effectiveness of ESG risk hedging as its fundamental elements. Then, we design a theoretical representation of ESG risk materiality under the FD legal constraints and identify that the current FD law binds investors to assimilate ESG risks to financial risks; thus, their management is required only if they are financially material for investments. We show that this principle equally applies to long-term ESG risks (like climate change); investors are incentivised to manage only those that are sufficiently financially material considering the applied hypothetical discount rate. Also, through the case study of a recent US ERISA ESOP lawsuit, we reveal that risk aversion towards probability to successfully hedge material ESG risks could impede efficient risk management by incentivising investors not to hedge a material ESG risk, i.e. to breach their FD.

在当今可持续投资策略快速增长的背景下，环境、社会和治理 (ESG) 风险管理与投资者信托责任 (FD) 下的投资管理要求的兼容性是关键问题之一。尽管在欧洲取得了一些法律进展，但投资者对这个问题仍然没有明确的答案，这使他们在面对这些新的、非常规的风险时显得无动于衷。在我们的研究中，我们探索了欧盟和美国法律实践的最新进展，目的是确定 FD 实际要求投资者在其投资管理决策中考虑 ESG 风险的程度。通过分析，我们定义了现行FD法设定的适用于投资者的ESG风险管理理论决策模式，并确定：1) ESG 风险重要性和 2) 作为基本要素的 ESG 风险对冲的有效性。然后，我们设计了 FD 法律约束下 ESG 风险重要性的理论表示，并确定现行 FD 法律约束投资者将 ESG 风险同化为金融风险；因此，只有当它们对投资具有重要的财务意义时，才需要对其进行管理。我们表明该原则同样适用于长期 ESG 风险（如气候变化）；考虑到所应用的假设贴现率，投资者被激励只管理那些在财务上足够重要的人。此外，通过最近美国 ERISA ESOP 诉讼的案例研究，