In summary, we would like to emphasize that LSL is a key parameter for the impact of climate change on the coastal zone. Its complexity and the large epistemic uncertainties associated with its forcing pose a major challenge to policy makers and decision making. We can reduce the uncertainties by improving our observational basis and thus our understanding of the processes that force LSL variations. Therefore, we both are engaged in global observing system, in particular the Group on Earth Observation (GEO) which is implementing the Global Earth Observation System of Systems (GEOSS), the Integrated Global Water Cycle Observing System (IGWCO), and the Global Geodetic Observing System (GGOS), which acknowledges sea level as one of the most demanding application of geodetic monitoring.