Satellite Based Support for Sea Level Dynamic Adaptation Policy Pathways

Sea level rise is a present risk to many of the world’s coastal communities, and this risk is expected to increase in the coming decades. As a result of this increased risk and worsening impacts, both in magnitude and frequency, efforts are now underway for coastal communities to adapt to future sea level rise. Such adaptation planning requires a foundation of scientific information about the timing and magnitude of future sea level rise. Complicating this, however, are the uncertainty and ambiguity in future estimates of sea level rise, which can serve to limit or paralyze decision-making. The magnitude of this uncertainty varies with time horizon making a “wait and see” approach an attractive adaptation option. However, a “wait and see” approach can potentially limit future adaptation options and ultimately prove more costly than acting in a more timely manner. As a solution to these challenges, the dynamic adaptation policy pathways (DAPP, often shortened to “adaptation pathways”) approach has been developed. Dynamic adaptation policy pathways, or DAPPs, provide roadmaps for coastal communities to establish the infrastructure and response needed for sea level rise resilience. Involving monitoring coordinated with response, these adaptation pathways require iterative assessment of sea level rise observations and model projections. Remote sensing capabilities from satellites offer an opportunity to assess a consistent set of observational data indicators, around which adaptation pathways can be built. The large-scale nature and broad coverage of satellite observations provide the benefit of consistent monitoring capabilities across the globe, for regions with differing needs, resources, and monitoring capacities. In this article, we identify four broad categories of data indicators that can be monitored with satellites to support decision making in adaptation pathways. We review these indicator categories in relation to existing adaptation pathway signposts and the available satellite data. As we highlight the opportunities for satellite-based contributions to sea level adaptation pathways, we also outline potential limitations, opportunities to overcome these limitations, and future steps that need to be taken to formally integrate satellite observations into adaptation pathways.