Alterations in climate due to increasing atmospheric concentrations of carbon dioxide and other trace gases must be viewed with concern, if not alarm, because of the risk of adverse impacts on the availability and quality of water resources. Hydrologic changes may lead to alterations in pressure on food resources in many regions of the world. This paper explores the mechanisms by which food security - defined here as the ability of a region to produce or otherwise provide food without threatening the well-being of either the population or the existing political systems - could be affected by climate-induced changes in water resources. Shifts in the timing, magnitude, or location of major hydrologic phenomena, such as runoff, soil moisture, or monsoons, are discussed, together with the important vulnerabilities of agricultural productivity to changes in water availability. Some of the concomitant political and socioeconomic implications are also presented, with suggestions for ways to enhance the reliability of food resources dependent on uncertain water supplies.

In this article the authors assess the potential impacts of projected climate change on water, livelihoods and food security in the Basin Focal Projet basins. The authors consider expected change within the context of recently observed climate variability in the basins to better understand the potential impact of expected change and the options available for adaptation. They use multi-global circulation model climate projections for the AR4 SRES A2a scenario, downscaled and extracted for each basin. They find significant differences in the impacts (both positive and negative impacts) of climate change, between and within basins, but also find large-scale uncertainty between climate models in the impact that is projected.

Water, energy, food, land and climate form a tightly-connected nexus in which actions on one sector impact other sectors, creating feedbacks and unanticipated consequences. This is especially because at present, much scientific research and many policies are constrained to single discipline/sector silos that are often not interacting (e.g., water-related research/policy). However, experimenting with the interaction and determining how a change in one sector could impact another may require unreasonable time frames, be very difficult in practice and may be potentially dangerous, triggering any one of a number of unanticipated side-effects. Current modelling often neglects knowledge from practice. Therefore, a safe environment is required to test the potential cross-sectoral implications of policy decisions in one sector on other sectors. Serious games offer such an environment by creating realistic ‘simulations’, where long-term impacts of policies may be tested and rated. This paper describes how the ongoing (2016–2020) Horizon2020 project SIM4NEXUS will develop serious games investigating potential plausible cross-nexus implications and synergies due to policy interventions for 12 multi-scale case studies ranging from regional to global. What sets these games apart is that stakeholders and partners are involved in all aspects of the modelling definition and process, from case study conceptualisation, quantitative model development including the implementation and validation of each serious game. Learning from playing a serious game is justified by adopting a proof-of-concept for a specific regional case study in Sardinia (Italy). The value of multi-stakeholder involvement is demonstrated, and critical lessons learned for serious game development in general are presented.