70 years of helping people to care for our ocean

Global Study Finds Planners Using a Wide Variety of Sea-Level Rise Projections

The first global survey to assess land use planners’ and coastal managers’ use of sea-level rise (SLR) projections in planning for crucial coastal adaptation finds almost universal recognition of the threats of SLR and significant work to incorporate projections into local decision-making. However, researchers also found a wide array of future projections in use and no global standard for how they are applied.

Our own coastal scientist, Dr Bronwyn Goble was one of 29 co-authors part of the publication that suggests a need to build better bridges between scientists and coastal managers. The study distributed the survey via a confidential questionnaire to coastal managers and practitioners in every inhabited continent, providing the questionnaire in English, Arabic, Chinese, French, Hebrew, Japanese, Korean, Portuguese, and Spanish. The questionnaire asked for specific time horizons and projection information currently used in coastal planning for areas under their jurisdiction, and if they were aware of the science behind the SLR projections used.

Two-hundred fifty-three practitioners from 49 countries provided complete answers to the survey. The study found that 72% of survey respondents reported using SLR projections in their coastal planning processes and that generally, developing countries have lower levels of incorporating SLR projection data, with no global standard.  Researchers found that 53% of locations are planning using a single projection and the remainder are applying multiple projections.

Lack of planning in many places is concerning as these developing countries will be among the places hardest hit by SLR. Pslans and policy actions that are triggered by specific changes in SLR can guide better decision-making and reduce the chances that money and efforts are invested in adaptation and mitigation efforts that are not effective. Those may include building sea walls and other infrastructure, prohibiting development in areas that are or will be directly affected, or moving people out of some communities.

Dr Goble notes that “The key is for policymakers to understand that planning for sea-level rise and climate change is as much about the now as it is for future needs. Poor planning and decision making will affect lives and livelihoods.” Thus, successful coastal adaptation requires robust integration of science and policy. The researchers note that building and designing these systems requires an understanding of how to make science-based decisions in the context of increasing uncertainties. The findings also highlight the need for policymakers to understand the importance of using SLR projections in planning for risk. Results of the study were published in Nature – Communications Earth & Environment, April 3, 2023.