Threading the needle: The delicate art of designing debt‐for‐nature swaps

Motivation Debt‐for‐nature swaps (D4NS) have re‐emerged as a potential instrument to address the dual challenges of sovereign‐debt distress and environmental degradation. Despite their growing use, particularly since 2021, their effectiveness as a “triple win” for debt relief, fiscal space, and conservation outcomes remains unclear, with existing evidence largely fragmented and case‐study‐based. Purpose This article aims to evaluate the effectiveness of D4NS across their evolution and to identify the conditions under which they can simultaneously deliver meaningful debt relief and environmental outcomes. It asks: how have D4NS performed across different generations and what design features are required to improve their impact? Approach and Methods The study compiles a transaction‐level database of 169 D4NS across 45 countries between 1987 and 2025. Building on earlier historical inventories, the database harmonizes available information on the face value of debt treated, repurchase terms, and environmental proceeds, enabling comparisons across transactions and generations. It introduces a financial assessment framework based on three core metrics: debt volume, repurchase discount, and environmental proceeds. These metrics are used to compare swaps across time and document recurring empirical patterns in their fiscal and environmental performance. Findings The analysis shows that early D4NS were environmentally effective but small in scale, while later generations achieved larger volumes, but often at the cost of weaker environmental outcomes and limited net debt relief. Nearly 70% of swaps occur during periods of debt distress, indicating that meaningful discounts, and thus fiscal gains, are rarely available outside crisis conditions. Overall, most swaps fail to simultaneously achieve all three objectives. Policy Implications D4NS are not a standalone solution but can play a complementary role in debt and climate strategies if carefully designed. The paper proposes a fourth generation of D4NS centred on a pre‐funded distressed‐debt facility to capture market dislocations, enabling larger‐scale debt relief and improved environmental outcomes through faster and more opportunistic execution.