Scale Dependencies of Sustainable Intensification and the Use of Integrated Assessment Modelling.

Sustainable intensification (SI) has received increasing attention as a promising concept to address the various challenges posed on agricultural production. Despite the number of different definitions available, there is growing consensus that SI needs to be addressed at multiple scales and organisational levels considering the different dimensions (environmental, economic, social) of sustainability. Scale dependencies of SI options receive particular interest in this respect. A number of metrics have been developed to measure SI options including trade-offs between these. SI metrics are often structured within indictor frameworks but full operationalization remains difficult due to the complexity of these frameworks trying to account for a range of quantitative and qualitative environmental and socio-economic indicators across scales. Integrated assessment modelling (IAM) is a way to estimate indicators at the respective SI dimensions and scales. Although considerable progress in IAM has been achieved, their use for multi-scale SI assessment based on sound indicator frameworks has received little attention. The paper reviews progress in using IAM for assessing SI options and points to key challenges. Selected examples are presented of IA models developed to assess impacts of climate change, technology development and policy change on agriculture at different scales and geographic regions. Although IAM approaches can address complex problems in agriculture their flexibility to account for different indicators and related frameworks is relatively small. Also, sound linkages to relevant indicators frameworks are lacking. Nevertheless, IAM provides an advanced approach to allow scale-and dimension-specific quantification of indicators based on rigorously tested models. As such IAM can also inform scientists and stakeholders about scale dependencies of SI options. Particular challenges of IAM used for SI include the proper linking of IA models to indicator frameworks relevant for SI and the requirements for these indicators frameworks and IA models to be flexible and generic, consistent and simple enough so that they can be understood by stakeholders. The paper discusses the urgency to meet these demands in the context of recent political agreements such as the COP21 climate agreement and the United Nations Sustainable Development Goals. The paper concludes with a set of suggestions to improve the use of IA models in conjunction with indicator frameworks to comprehensively explore SI options across the different dimensions and scales.