5. Conclusions
The agreed UN SDGs are a major achievement in the development of shared goals for all of humanity. The SDGs have been agreed to by all UN member states and they include economic, social, and environmental elements. However, they lack an overarching goal and an effective aggregate indicator of progress toward that goal. One could argue that such an aggregate indicator is not necessary (or possible) and that the pursuit of the individual goals will be sufficient to achieve sustainable development. That might be true if the goals were independent of each other and they all contributed to the overarching goal equally. This is obviously not the case, especially in the context of the widely different situations in each country. We need an aggregate indicator that can assess the relative contribution of each of the SDGs and their interactions with each other in order to assess overall progress. We have suggested three fundamental categories that could make up a hybrid indicator and how they could be combined, but we also propose the development of an underlying systems dynamics model to assess interactions and synergies over space and time, including both stocks and flows, causes and effects. It is also necessary to develop a framework of policy reforms and societal change that make the achievement of the SDGs possible at both the national and global level. In today's interconnected world, the SDGs cannot be achieved unless there is sustainable wellbeing globally. We hope that the SDG process will continue in the direction we have proposed in order to speed the approach to a sustainable and desirable future.
