This project explored the implementation of the Sustainable Development Goals (SDGs) within planetary boundaries, focusing on Fiji as a case study for small island developing states (SIDS). It evaluates the viability of various policy and investment scenarios in achieving SDGs by 2030 and their alignment with environmental sustainability up to 2050. The project employs the integrated iSDG-Fiji system dynamics model to simulate business-as-usual and six alternative future scenarios. The findings underscore the necessity of ambitious actions to achieve SDG targets, highlighting that modest investments can significantly improve SDG performance, but more comprehensive and ambitious strategies are required to fully align with both the SDGs and environmental sustainability goals.