VLM-SLC · Disentangling Vertical Land Motion Processes for Future Sea Level Change Projections

As one of the most direct effects of climate change, sea level change will have drastic consequences for coastal populations, industries, and ecosystems in the coming century. Coastal relative sea level change is additionally driven by vertical land motion, which can be as large as climate-driven absolute sea level change (mm/year - cm/year) and is expected to have similar impacts as climate-driven sea level rise in the short term (~30 years). However, there is only ‘low to medium confidence’ in state-of-the-art vertical land motion projections and their uncertainties at the global scale. This is because the majority of previous sea level projection studies employed simplified assumptions of vertical land motion, i.e., they used limited data sources, neglected the full spectrum of vertical land motion processes (e.g., tectonic or human induced effects, etc.), and did not consider non-linear changes, which are crucial to understand the predictability of vertical land motion.To overcome these limitations, I propose here an interdisciplinary approach, to develop a probabilistic spatio-temporal model that will provide estimates of vertical land motion at unprecedented spatial and temporal resolution (from 1900 to present). This will be the first global-scale effort to integrate paleo-sea-level records, modern measurements (e.g., GNSS (Global Navigation Satellite System), tide gauges, InSAR (Interferometric Syntethic Aperature Radar), satellite altimetry), physical models (e.g., GIA models), and ancillary information from climate models. I hypothesize that combining these different data sources is key to disentangle vertical land motion processes, such as GIA, tectonic, and other natural or human-induced effects. The outcome of this project will be process-based vertical land motion projections on a global scale that distinguish between long-term linear motions and non-linear effects, and that include rigorous uncertainty quantification.