Coherently addressing the 17 Sustainable Development Goals requires planning tools that guide policy makers. Given the integrative nature of the SDGs, we believe that integrative modelling techniques are especially useful for this purpose. In this paper, we present and demonstrate the use of the new System Dynamics based iSDG family of models. We use a national model for Tanzania to analyse impacts of substantial investments in photovoltaic capacity. Our focus is on the impacts on three SDGs: SDG 3 on healthy lives and well-being, SDG 4 on education, and SDG 7 on energy. In our simulations, the investments in photovoltaics positively affect life expectancy, years of schooling and access to electricity. More importantly, the progress on these dimensions synergizes and leads to broader system-wide impacts. While this one national example illustrates the anticipated impact of an intervention in one specific area on several SDGs, the iSDG model can be used to support similar analyses for policies related to all the 17 SDGs, both individually and concurrently. We believe that integrated models such as the iSDG model can bring interlinks to the forefront and facilitate a shift to a discussion on development grounded in systems thinking.

Non-technical The world agreed to achieve 17 Sustainable Development Goals by 2030. Nine planetary boundaries set an upper limit to Earth system impacts of human activity in the long run. Conventional efforts to achieve the 14 socio-economic goals will raise pressure on planetary boundaries, moving the world away from the three environmental SDGs. We have created a simple model,Earth3, to measure how much environmental damage follows from achievement of the 14 socio-economic goals, and we propose an index to track effects on people's wellbeing. Extraordinary efforts will be needed to achieve all SDGswithinplanetary boundaries.

Significance: The sustainable development goals (SDGs) offer the global community a compelling vision and universally agreed-upon framework to achieve a sustainable and equitable future—but present a costly undertaking in the short term. Our research suggests that synergetic effects arising from appropriately designed policy mixes can bring significant cost savings and improve SDG attainment. Identifying and quantifying synergies requires innovative and unorthodox approaches to policy analysis such as those operationalized in our 3 pilots. The synergy assessment method and typology introduced in this paper are widely applicable, even though the patterns of synergies vary considerably between countries. Our pilot studies focus on national policy for the SDGs. Our approach is nevertheless generalizable to integrated planning at other scales and time horizons.

Background: The Planetary Boundaries concept (PBc) has emerged as a key global sustainability concept in international sustainable development arenas. Initially presented as an agenda for global sustainability research, it now shows potential for sustainability governance. We use the fact that it is widely cited in scientific literature (>3500 citations) and an extensively studied concept to analyse how it has been used and developed since its first publication. Design: From the literature that cites the PBc, we select those articles that have the terms ‘planetary boundaries’ or ‘safe operating space’ in either title, abstract or keywords. We assume that this literature substantively engages with and develops the PBc. Results: We find that 6% of the citing literature engages with the concept. Within this fraction of the literature we distinguish commentaries—that discuss the context and challenges to implementing the PBc, articles that develop the core biogeophysical concept and articles that apply the concept by translating to sub-global scales and by adding a human component to it. Applied literature adds to the concept by explicitly including society through perspectives of impacts, needs, aspirations and behaviours. Discussion: Literature applying the concept does not yet include the more complex, diverse, cultural and behavioural facet of humanity that is implied in commentary literature. We suggest there is need for a positive framing of sustainability goals—as a Safe Operating Space rather than boundaries. Key scientific challenges include distinguishing generalised from context-specific knowledge, clarifying which processes are generalizable and which are scalable, and explicitly applying complex systems’ knowledge in the application and development of the PBc. We envisage that opportunities to address these challenges will arise when more human social dimensions are integrated, as we learn to feed the global sustainability vision with a plurality of bottom-up realisations of sustainability.

Cities are vital for achieving the Sustainable Development Goals (SDG), but different local strategies to advance on the same SDG may cause different ‘spillovers’ elsewhere. Research efforts that support governance of such spillovers are urgently needed to empower ambitious cities to ‘account globally’ when acting locally on SDG implementation strategies.