This chapter discusses uncertainties related to the impacts of climate change on marine social‐ecological systems, with a focus on the management and governance challenges in helping fisheries to adapt. Four types of uncertainty are identified, relating
to observations, models, processes, and the development and implementation of policies. Observation uncertainty occurs due to natural variability and difficulties in making accurate observations. Model uncertainty is due to wrong or incomplete processes being
included in the model and to a lack of knowledge of model parameter values. Process uncertainty results from a lack of knowledge of how the system is structured and how it functions and, in the case of socialecological systems, includes uncertainty over human behavioural
responses. Policy uncertainty recognises that policies are not applied perfectly, may be inappropriate for the given situation, and includes difficulties in communicating amongst stakeholders and policy makers.