Using Sea-Level Science to Manage Climate Change Risks

The impacts of sea-level rise pose a threat to coastal communities, ecosystems, and economies. Adaptation strategies to cope with and deal with sea-level rise involve infrastructure and coastal development, which can affect the vulnerability and exposures of the community and coastal assets for many generations to come.

Researchers Robert Kopp, Elisabeth Gilmore, Christopher Little, and others look at the usability of sea-level science in managing risks. But ensuring usability comes with many challenges or questions that cannot be answered by sea-level projections, such as:

1. Deep uncertainty in sea-level projections is the uncertainty in future anthropogenic emissions when considering the complexities of political, economic, and technological involvement.
2. Robustness of Bottom-Up projections. This relies on the various models and the assumptions used to calculate each term, e.g. ice sheet and glacier mass loss, rate of anthropogenic emissions, global temperature rise, etc., into the equation.
3. The utility of probabilistic approaches. Probabilistic projection attempts to provide a probability of future sea-level change based on emissions scenarios. One benefit of this is to provide a framework for summarizing knowledge in the face of uncertainty. Probabilistic language is used, for example, “likely” or “probable,” as these terms appeal to stakeholders oriented towards benefit-cost analysis and financial risk analysis.

The paper provides an overview of the sea-level science relevant to decision-makers and communities as they develop their future coastal adaptation strategies. Ultimately, it should combine the four basic approaches to coastal adaptation: accommodation of more frequent flooding through social, economic, and engineering changes; defence against flooding; advance reclamation of land from the ocean; and relocation through planned migration.  

Determining how to combine these approaches would require considering physical hazards due to sea-level rise, human response to their changing environment, and the use of a decision-science approach to construct strategies that can withstand uncertainties and political and sociological barriers.