Evolution of Global Sea-level Rise Projections for the 21st Century and their Incorporation in Local and Regional Assessments

Abstract:

The potential effect of global warming on sea level and the possible impacts of sea-level rise on ecosystems, infrastructure, and society began to be realized nearly four decades ago, leading to the first global sea-level rise projections in the early 1980s. Subsequent projections have helped to improve understanding of the processes driving sea-level rise and develop new methods of projecting future sea-level rise. Despite these advances, future sea-level rise remains deeply uncertain at both global and regional scales. To facilitate understanding of the historical development of global sea-level rise projections and provide context for interpreting the current state of the art, we present an update to our database of 21^st century global sea-level rise projections (Garner et al., 2018). Our results show that the range of projected global sea-level rise has varied greatly over time. Upper projections of sea-level rise from individual studies are generally higher than upper projections from the Intergovernmental Panel on Climate Change, potentially due to differing percentile bounds, or a pre-disposition of consensus-based approaches toward relatively conservative outcomes.

We also present a new database of sea-level rise assessment documents that are used at the local scale from two distinct regions: North America and Asia. Results of this work aim to help inform both the scientific and decision-making communities, by analyzing differences in the scientific approaches used to develop local sea-level rise assessments across regions, and highlighting how scientific knowledge can and should guide policy-making and communication between academic and decision-making sectors.