Based on the ongoing large climatic and environmental changes and the history of science coordination in Svalbard leading to the development of Svalbard Integrated Arctic Earth Observing System (SIOS), we present an overview of the current gaps in knowledge and infrastructure based on a synthesis of the recommendations presented in the annual State of Environmental Science in Svalbard (SESS) reporting of SIOS. Recommendations from the first 4 years of SESS reporting represent the point of view of the wide scientific community operating the large observing system implemented in Svalbard (SIOS) since 2018 and aim to identify the scientific potential to further develop the observing system. The recommendations are bottom-up inputs for a continuous process that aims to accomplish the vision and mission of SIOS: optimizing, integrating and further developing the observing system in an Earth system science (ESS) perspective. The primary outcome of the synthesis work is the evidence that ESS in SIOS has, during the first 4 years of operation, naturally developed from individual scientists or smaller groups of scientists to larger disciplinary international groups of scientists working together within the different environments (the atmosphere, the cryosphere, and marine and terrestrial environments). It is clear that strategic efforts towards interdisciplinarity are necessary for operating fully at ESS scale in Svalbard. As Svalbard is experiencing the largest ongoing warming in the Arctic and worldwide, SIOS is in a unique position to perform a full-scale study of all processes impacting ESS dynamics and controlling the water cycle using all parts of the SIOS observation network, with a large potential for increasing the understanding of key mechanisms in the Earth system. We also identify the potential to upscale Svalbard-based observations collected in SIOS to pan-Arctic and global scales, contributing to full-scale ESS.