States of ‘Knowing’: Uncertainty, Ambiguity and Risk in SIDS Climate Change Impacts

This chapter considers the questions of not only what we know about climate change impacts for Small Island Developing States (SIDS) but also how we know what we know, and how well we know what we know. The term ‘climate change risk’ implies strong knowledge about the possible outcomes and their probabilities, and thus a firm basis for conventional, computation-based decision-making strategies. However, what we ‘know’ about climate change impacts is often uncertain—where knowledge about possible outcomes is strong but knowledge of their likelihood is weak—or ambiguous, where knowledge of possible outcomes is limited but probabilities can be assigned for those that are known. Therefore, this chapter presents a critical analysis of quantitative (e.g. climate models, meteorological datasets) and qualitative (e.g. historical photography, narrative accounts) approaches used to study climate change impacts, focusing on their applicability in island contexts, where smallness, boundedness and isolation may present challenges which are more pronounced than at broader scales. It explores how the inherent limitations of various data and methods, alongside the nonlinearity and unpredictability of the climate system, give rise to uncertainty and/or ambiguity, and in light of this, discusses how climate data can reasonably inform decision-making relating to climate change impacts for SIDS.