<p>The ability of decision makers to respond to climate change impacts such as sea-level rise and increased flood frequency is challenged by uncertainty about scale, timing, dynamic changes that could lead to regime shifts, and by societal changes. Climate change adaptation decision making needs to be robust and flexible across a range of possible futures, to provide sufficient certainty for investment decisions in the present, without creating undue risks and liabilities for the near and long-term futures. A country’s governance and regulatory institutions set parameters for such decisions. The decision-making challenge is, therefore, a function of the uncertainty and dynamic characteristics of climate change, a country’s institutional framework, and the ways in which actual decision-making practice delivers on the intention of the framework. My research asks if the current decision-making framework, at national and sub-national scales, and practices under it are adequate to enable decision makers to make climate change adaptation decisions that sufficiently address the constraints posed by climate change uncertainty and dynamic change. The focus is on New Zealand’s multi-scale governance and institutional framework with its high level of devolution to the local level, the level assumed as the most appropriate for climate change adaptation decisions. Empirical information was collected from a sample of agencies and actors, at multiple governance scales reflecting the range of geographical characteristics, governance types, organisational functions and actor disciplines. Data were collected using a mix of workshops, interviews and document analyses. The adequacy of the institutional framework and practice was examined using 12 criteria derived from the risk-based concepts of precaution, risk management, adaptive management and transformational change, with respect to; a) understanding and representing uncertainty and dynamic climate change; b) governance and regulations; and c) organisations and actors. The research found that the current decision-making framework has many elements that could, in principle, address uncertainty and dynamic climate change. It enables long-term considerations and emphasises precaution and risk-based decision making. However, adaptive and transformational objectives are largely absent, coordination across multiple levels of government is constrained and timeframes are inconsistent across statutes. Practice shows that climate risk has been entrenched by misrepresentation of climate change characteristics. The resulting ambiguity is compounded at different governance scales, by gaps in the use of national and regional instruments and consequent differences in judicial decisions. Practitioners rely heavily upon static, time-bound treatments of risk, which reinforce unrealistic community expectations of ongoing protections, even as the climate continues to change, and makes it difficult to introduce transformational measures. Some efforts to reflect changing risk were observed but are, at best, transitional measures. Some experimentation was found in local government practice and boundary organisations were used as change-agents. Any potential improvements to both the institutional framework and to practices that could enable flexible and robust adaptation to climate change, would require supporting policies and adaptive governance to leverage them and to sustain decision making through time. This thesis contributes to understanding how uncertainty and dynamic climate change characteristics matter for adaptation decision making by examining both a country-level institutional framework and practice under it. The adequacy analysis offers a new way of identifying institutional barriers, enablers and entry points for change in the context of decision making under conditions of uncertainty and dynamic climate change.</p>