Integrated assessments of climate variability and change for Australian agriculture - Connecting the islands of knowledge

Key clients for regional or national assessment capabilities are government and industry policymakers, who must deal with constantly changing policy questions. For instance, adaptation to climate change has relatively recently come onto the policy agenda, as has the interaction between adaptation and greenhouse gas mitigation. 'Integrated assessment' has therefore become a common approach that attempts to demonstrate the policy relevance of science. It is intended to inform policies that ultimately lead to better risk management of agro-ecosystems (amongst other objectives). Increasingly policy stakeholders also demand realistic assessments of uncertainties that are associated with the scenarios underpinning such integrated assessments. This requires quantitative, probabilistic evaluation of risks and opportunities associated with specific scenarios that need to supplement the overall, qualitative assessments. Such evaluations can help to cut through the complexity of policy related issues without sacrificing the holistic perspective needed to maintain policy relevance. Using climate change as an example, we explore the role of quantitative models for integrated assessments and argue that a nested modelling approach (eg. climate model - biophysical model - socio-economic model - engagement model) to address all relevant disciplines, stakeholders and scales not only provides the quantitative information needed, but is also a valuable process to negotiate the complexities of the policy domain. This process might help us move more quickly from impact assessments (ie. unadapted responses) to well-structured scenario planning with adaptation, a process that is both policy and response informing.