Novel framework for probabilistic sea-level projections for Singapore and surrounding regions

Project Overview

Future sea-level rise will generate hazards for coastal populations, economies, and infrastructure of Singapore. Our objective is to develop a novel framework to integrate the probabilistic sea-level projections and their uncertainties for Singapore and surrounding regions by 2100 under different emission scenarios. We will achieve this with a combination of three approaches: (1) Refining the climate models used in our analysis by targeting those which accurately represent regionally important processes including thermal expansion, ocean dynamics, glacier melt, ice sheet contributions, and land water storage; (2) With a focus on regional ocean circulation and its impact on sea level we will validate not only climate models, but also a higher resolution model that resolves more of the relevant regional ocean dynamics; and (3) We will synthesise sea-level rise in a statistical framework (using copulas) that describes probabilistic sea-level projections for the region. The use of copulas is novel in sea-level research. This statistical tool is particularly relevant here because, unlike previously applied methods, it considers the uncertainty and correlations between the component changes of sea level which results in a better description of the combined processes, particularly at the high tail end or extreme sea levels. High-end upper-tail projections are the greatest risk, produce the largest damages, and highest prospective costs in planning adaptation. In addition, we will strengthen our estimates of the confidence interval of the uncertainties by employing graphical copulas to model the statistical effects of downscaling and the collective correlated influences of the spatially dependent components. Our resulting statistical framework couples the uncertainty of sea-level components at different spatial scales, while enabling the evaluation of systemic uncertainties which serve to inform the potential occurrence of regime shifts towards the climatic extreme. It can also handle updated information from CMIP6 simulations at the same time.

We aim to develop a novel framework for probabilistic sea-level projections for Singapore and surrounding regions. The specific objectives are:

1. Develop the framework to integrate the probabilistic sea-level projections and their uncertainties for Singapore and surrounding regions by 2100 with selected climate scenarios.
2. Quantify uncertainties in components of relative sea-level rise in Singapore and surrounding regions, including local ocean dynamics.
3. Coupling different components of relative sea-level rise with Copulas.

Funding Source

• National Sea Level Programme
• National Environment Agency

Project Years

2021 to 2025