System dynamics modelling to explore the impacts of policies on the water-energy-food-land-climate nexus in Latvia.

The water-energy-food (WEF) nexus is a complex system operating at many scales, the importance of which is increasingly recognized in academia and policy. There are calls to expand the nexus to include land and climate (WEFLC) as well as to narrow the science-policy divide, implying conducting assessments at policy-relevant scales to assess the impacts of policy objectives. This paper presents a national-scale WEFLC nexus system dynamics modelling assessment for Latvia. Qualitative and quantitative assessment was performed with local stakeholders to validate model structure, data, results, and to gather information on Latvian policy objectives and implement them in the model as potential future policies. Under baseline conditions (i.e. without implementing goal-specific policies under shared socio-economic pathway 2), results indicate a levelling off of consumption by 2050 while production of food products and energy is expected to increase. Nitrogen losses and climate emissions increase, going against policy targets. Implementation of indicative policies has desired impacts within their given sector, but may lead to trade-offs in others. Implementing multiple policies simultaneously may augment or hinder progress towards objectives due to system interconnectedness. Therefore, when choosing which policies to implement, cross-sectoral implications must be carefully considered. This work offers insight for policy and decision making in Latvia, hinting at policy options to pursue, and highlighting those to avoid. This study offers suggestions for closing the science-policy divide including the use of visual serious game environments for results interpretation, the use of selected indicators for nexus performance assessment, and close stakeholder engagement throughout a project.