Permanence Risks to Biodiversity and Nature-Based Carbon Offsets

Biodiversity and nature-based carbon offsets are central to strategies addressing biodiversity loss and climate change. Their credibility depends on permanence—the expectation that biodiversity gains or sequestered carbon persist at least as long as the impacts they compensate for, or in perpetuity. Yet ecosystems are dynamic and increasingly exposed to disturbance, making perpetual outcomes difficult to guarantee. Despite this, many offset programs rely on fixed durations and static assumptions ill-suited to managing long-term risks, creating a structural misalignment between ecological permanence and the safeguards intended to secure it. To assess this misalignment, we reviewed three decades of literature to identify risks to long-term durability and strategies for managing them. We developed a typology spanning three domains. Non-physical risks, such as weak governance and limited data transparency, were most frequently reported, often co-occurred, and enabled other failures. Physical risks such as fire, storms, or flooding cause material damage and are intensifying with climate change. Methodological risks, including oversimplified metrics and flawed design, expose structural weaknesses in offset systems. Our typology provides a framework for assessing permanence risks and strengthening offset governance. Credible, enduring offsets are achievable, provided robust risk management and adaptive governance are aligned with ecological realities.