Limits to Adaptation

Synthesis and Integrative Research Program


A core function of NCCARF is to conduct a program of research that synthesises and integrates existing and emerging national and international climate change adaptation knowledge. One mechanism for delivering this program is through modular Projects. Each Project consists of a number of sections which address one aspect of the project theme, and together they contribute a substantial body of work on the theme.

Projects undertaken to date using the modular approach include a Forest Vulnerability Assessment, the Historical Case Studies of Extreme Events, and an Adaptive Capacity Synthesis Report. This document outlines a Project on the theme of the limits to adaptation.

Download the Key Findings from this project (700kb pdf) or a suite of six two-page summaries (2.6mb) of key findings from each report

Download completed project reports


Much of the research on adaptation avoids the question of what adaptation cannot achieve. It is therefore implied by omission that adaptation can avoid all climate impacts. Yet this is clearly not going to be the case for many systems, sectors and places at even modest rates of warming, let alone at the more rapid rates of warming that now seem almost inevitable.

The notion of ‘limits to adaptation’ is fundamentally concerned with identifying the thresholds at which actions to adapt cease to reduce vulnerability.These thresholds exist in four domain.

First, there are ecological and physical thresholds beyond which unplanned or planned responses fail to avoid climate change impacts. For example, there seems likely to be a threshold beyond which no amount of human action can avoid repeated and severe coral bleaching.

Second, there are economic thresholds, which are where the costs of adaptation exceed the costs of impacts averted (that is, it is more expensive to adapt than it is to experience climate impacts). For example, while it seems the costs of protecting cities from sea-level rise are less then the costs of the impacts, the same may not be said for protecting rural coastal settlements. It is important to recognise, however, that this is effectively a social rather than a technical judgment as ‘cost’ here should include both monetary and non-monetary costs, and consideration of non-climate-change related benefits.

Third, there are technological thresholds beyond which available technologies cannot avoid climate impacts. For example, under certain climatic conditions snow-making machines may be able to sustain snow cover for the purposes of skiing (if not for species dependent on the snow-pack), but ultimately climate may change to the point where snow making is no longer possible. Similarly, there may be limits to engineering solutions to avoid flooding in certain places under extreme scenarios of change.

It is important to recognise that the identification of limits in these three domains is not strictly an objective process: all entail judgments of expected outcomes to be in some way negative, and all such judgments are effectively based on social values. Therefore, it is important that research on the limits to adaptation carefully explain why the expected impacts either before, after or because of adaptation measures would be considered negative (or not) by sections of society. Evidence for this may be readily available: for example the classification of the Great Barrier Reef as a World Heritage Area clearly identifies that the reef is valued by parties to the World Heritage Convention for its ecological characteristics, and that the reef is an important site for tourists and tourism businesses further indicates different dimensions of its value and different kinds of stakeholders. In other cases, however, the value of an entity at risk may be less obvious, and may require further investigation.

The fourth domain within the limits to adaptation recognizes the subjective nature of the limits to adaptation, and concerns the points at which social groups judge adaptation actions to have failed. These social limits arise when the goals of adaptation decisions, and the proposed measures of their success, fail to consider the values and views of different groups that may be affected. Because the systems that may be part of adaptation processes consist of diverse groups that value things differently, what may be perceived as a successful adaptive response from one point of view may not be perceived the same way by others. For example, increasing the supply of water to a city through desalinisation increases the costs of water, which low-income groups would consider to be a worse outcome than alternative cheaper responses such as recycling water or restrictions on use.

Understanding the limits to adaptation is an emerging frontier of climate change research. It is important for decision making about adaptation for three reasons. First, it helps to determine which responses to climate change are both practicable and legitimate, and the time scales over which adaptation may be considered to be effective. Second, it helps to understand how people may respond to the damage to, or the loss of, things that are important to them, for which there may, in some cases, be substitutes or ameliorating policy measures. Third, it can help prioritise adaptation strategies, refine their intentions, and identify communities that will be served by them.