Limits of Acceptable Change

This paper gives a broad overview of existing approaches and other considerations concerning the definition and operation of concepts and approaches for “limits of acceptable change” (LAC) which may be applicable to the Ramsar context of defining and detecting change in the ecological character of wetlands, as required by Article 3.2.The paper identifies different purposes for LAC in the context of existing Ramsar information management and decision-making frameworks. It highlights conceptual distinctions between interpretations of “trivial” change, benchmarks for establishing the range of normal variability, recreational management compromise protocols, precautionary envelopes for ecosystem status reporting, early warning indicators, adaptive management triggers, expressions of risk appetite and degrees of approximation/tolerance bandwidths for the achievement of conservation objectives.Examples of existing approaches are given from Australia, the European Union, South Africa, the United Kingdom, and the United States, as well as from the Convention’s own guidance. Some of these approaches operate with substantial volumes of data and well-resourced agencies, but any global Ramsar standards or guidance which may be developed on this issue will need to cater for more capacity-constrained parts of the world, perhaps through a “framework” or “tiered” approach. Elements of the scope of desirable future work by the Ramsar Scientific & Technical Review Panel towards this are identified.The term “Limits of Acceptable Change” has been used in significantly different ways in different contexts, giving rise to some confusion and mistaken conceptual extrapolations. It is suggested that different terminology should be used for defining “how much change constitutes relevant change” for the purposes of Article 3.2. For Article 3.2 purposes it is therefore recommended that the term “Limits for Defining Change in Ecological Character” (LDCEC) should be used instead.