Abstract: • The recent Intergovernmental Panel on Climate Change Fourth Assessment Report (Hennessy et al. 2007; IPCC 2007b) concluded that the agriculture sector in Australia is particularly vulnerable to climate changes, with potential negative impacts on the amount of produce, quality of produce, reliability of production and on the natural resource base on which agriculture depends. This vulnerability requires high levels of adaptive responses. • The benefits and positive opportunities presented by climate change may start to peak during the initial stages (possibly mid century), but the negative impacts may lag behind, becoming progressively stronger over time and with greater build up of greenhouse gases in the atmosphere. Caution is therefore needed not to underestimate the long-term challenge of climate change based on initial, more moderate experiences. • This review has identified a number of potential options for Australian agriculture to adapt to climate change. Many of these options are extensions or enhancements of existing activities that are aimed at managing the impacts of existing climate variability and improving the sustainability and efficiency in the use of natural resources. • However, less than a dozen of these potential adaptation options have been evaluated for their utility in reducing the risks or taking advantage of climate change impacts. Only a couple of adaptations have been evaluated in relation to the broader costs and benefits of their use. • These few analyses show that practicable and financially-viable adaptations will have very significant benefits in ameliorating risks of negative climate changes and enhancing opportunities where they occur. The benefit to cost ratio of undertaking R&D into these adaptations appears to be very large (indicative ratios greatly exceed 100:1). • A key recommendation is thus to progress some more adaptation studies which analyse the costs and benefits of implementation of adaptations (including socio-economic aspects as well as potential feedbacks through greenhouse emissions). This R&D needs to be undertaken in a participatory way with industry groups so as to deal effectively with their key concerns, draw on their valuable expertise and also contribute to enhanced knowledge in the agricultural community. • There will always be uncertainty about future climate change impacts due to highly uncertain levels of future greenhouse emissions; fundamental uncertainty in the science of the global climate system; uncertainty about how specific changes in climate will affect agricultural/ ecological / social systems, and uncertainty in how communities will respond to these changes. • Uncertainties are greatly compounded by the complexities of scaling down to finer scales, so generalities about broad-scale impacts of climate change are difficult to translate into specific predications for particular management units (farms / properties / marine areas). Instead, riskbased approaches should be used, focusing on the range of plausible impacts that could occur, rather than potentially-misleading ‘average predictions’. • Given this inherent uncertainty, the need is to develop enhanced adaptive capacity in agricultural systems (including socio-economic and cultural/institutional structures) to cope with a broad range of possible changes. Synergies with existing Commonwealth policies such as self-reliance in drought and their supporting programs such as Advancing Australian Agriculture as well as with institutions such as Landcare are needed develop this capacity. • To cope with uncertainty in projected climate but the certainty of ongoing technological, cultural and institutional change, there is a need to use an active adaptive management approach for adaptation. This requires directed change in management or policy that is monitored, analysed and learnt from, so as to iteratively and effectively adjust to ongoing climate changes. Such an approach has profound implications for capacity-building, R&D, monitoring and policy. • Successful adaptation to climate change will need both strategic preparation and tactical response strategies. Adaptation measures will have to reflect and enhance current ‘best-practices’ designed to cope with adverse conditions such as drought. Adoption of these new practices will require, amongst other things 1) confidence that the climate really is changing, 2) the motivation to change to avoid risks or use opportunities, 3) demonstrated technologies to enable change to occur, 4) support during transitions to new management or new land use, 5) altered transport and market infrastructure and 6) an effective monitoring and evaluation system to learn which adaptations work well, which do not and why. • Many potential adaptation options are common across industries. These common or crossindustry themes are outlined immediately below. Industry-specific knowledge gaps and priority action areas are summarised in the next table (with more detailed tables provided at the end of each chapter). The final two synthesis tables summarize regional variation in terrestrial and marine climate change impacts.