Quantifying processes contributing to marine hazards  to inform coastal climate resilience assessments,  demonstrated for the Caribbean Sea

Lucy Bricheno,David Byrne,Jennifer Brown,Stefanie Rynders,Andy Matthews,Svetlana Jevrejeva,Hindumathi Palanisamy,Judith Wolf,Michela De Dominicis

doi:10.5194/nhess-20-2609-2020

Quantifying processes contributing to marine hazards to inform coastal climate resilience assessments, demonstrated for the Caribbean Sea

Lucy Bricheno, David Byrne + Show 7 more

Open Access

https://doi.org/10.5194/nhess-20-2609-2020

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Abstract

Abstract. Scientific evidence is critical to underpin the decisions associated with shoreline management, to build climate-resilient communities and infrastructure. We explore the role of waves, storm surges and sea level rise for the Caribbean region with a focus on coastal impacts in the eastern Caribbean islands. We simulate past extreme events and a worst-case scenario, modelling the storm surges and waves, suggesting a storm surge might reach 1.5 m, depending on the underwater topography. Coastal wave heights of up to 12 m offshore and up to 5 m near the coast of St Vincent are simulated with a regional wave model. We deliver probabilistic sea level projections for 2100, with a low-probability–high-impact estimate of possible sea level rise up to 2.2 m, exceeding the 1.8 m global estimate for the same scenario. We introduce a combined vulnerability index, which allows for a quantitative assessment of relative risk across the region, showing that sea level rise is the most important risk factor everywhere but wave impacts are important on windward coasts, increasing to the north, towards the main hurricane track. Our work provides quantitative evidence for policy-makers, scientists and local communities to actively prepare for and protect against climate change.

Highlights

Climate change is happening worldwide – no region on Earth has escaped it (IPCC, 2014)
We introduce a combined vulnerability index, which allows for a quantitative assessment of relative risk across the region, showing that sea level rise is the most important risk factor everywhere but wave impacts are important on windward coasts, increasing to the north, towards the main hurricane track
Historical observations (Fig. S5) of sea level rise in the Caribbean region are limited compared to other regions, which hinders the assessment of coastal impacts and vulnerability in the region (Holgate et al, 2013)

Summary

Introduction

Climate change is happening worldwide – no region on Earth has escaped it (IPCC, 2014). Caribbean small island states are vulnerable to coastal climate change since the socio-economics of small islands rely on the preservation of the coastal zone This presents a significant risk to the region’s people (IPCC, 2014; Caribbean Marine Climate Change Report Card, 2017; CARIBSAVE, 2012). Small Island Developing States (SIDS), with a high concentration of population, infrastructure and services in the low-lying coastal areas, are exposed to rising sea levels, intense storms and coastal erosion. These are already posing severe threats to people (property, infrastructure and livelihoods, such as tourism and artisanal fisheries) and the marine and coastal ecosystems that support them (Rhiney, 2015). They can have a severe impact on the economy, in some cases costing over 100 % of GDP for a single event (Jevrejeva et al, 2018; Monioudi et al, 2018; Caribbean Marine Climate Change Report Card, 2017; CARIBSAVE, 2012)

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