We have a favourite beach we visit on holidays, and through the seasons we observe the shifting form of the beach. Sand dunes drift and migrate, and the estuary often changes taking different winding routes to link the lagoon and the sea. Coasts are dynamic, shaped by tides, seasons, and storms. I can readily bring to mind images of dramatic cyclone damage and storm surges, but it is much harder for me to appreciate the risks of slow and steady increases in sea level upon our coastlines.
Sea level rise is an important predicted impact of global climate change. Current estimates for sea level rise range in Australia between 0.25- 0.80 m by the end of this century[i]. Sea level rise will contribute to increased inundation and erosion of shorelines, salinisation of coastal water tables and increased damage from coastal storms and storm surge events. Sea level rise will slowly inflict salt damage to critical infrastructure including roads, stormwater systems and wastewater treatment facilities. Flooding of low-lying coastal areas will become increasingly frequent during high tides and storm events due to sea level rise.
This book describes the mechanisms behind sea level rise and then unpacks the impacts predicted as a result. Two of the authors are geologists and the scientific explanations in the book are sound and straightforward, although the tone can tend towards exasperation especially when discussing politics and coastal development. Several case study chapters focus on examples from the United States where major cities such as Miami and New Orleans are particularly at risk of damage from sea level rise, although for different underlying reasons. New Orleans is built on a subsiding delta so the land is sinking at the same time as sea levels are rising. The argument is made that fortifying every coastal city against sea level rise will be too costly for the US federal government, so cities such as New Orleans may eventually be abandoned if repeatedly damaged by hurricanes. Miami is vulnerable to sea level rise because the city is built on porous limestone so there is no simple way to exclude rising seawater from the groundwater beneath the city. The authors are scathing of billion dollar developments currently underway on the low-lying coastal barrier island of Miami Beach. In contrast they commend New York City officials who commissioned an analysis of the damage following Hurricane Sandy which proposed coastal protections for vulnerable neighbourhoods, taking into account predicted sea level rise.
The authors criticise the cost to the US taxpayer of government insurance schemes subsidising repeatedly rebuilding damaged homes following natural disasters. They call for enforcement of regulations restricting development density in areas at risk of inundation and political leadership for managed retreat from vulnerable coastlines. The authors frequently adopt a frustrated tone describing the current US context of readiness to develop, build and rebuild in vulnerable coastal zones.
A chapter on environmental refugees describes the threat to Pacific island nations and low-lying countries such as Bangladesh where rising salty sea water will threaten drinking water and crops well before low-lying areas are inundated. The authors point out that environmental refugees do not have the legal status of political refugees under current international agreements.
The authors reach the conclusion that retreat from the coast is inevitable, and the expense of constructing barriers to hold back the sea can’t be justified along much of our coastlines. Reading this book will give you a good overview of the predicted impacts of sea level rise upon coastal cities. There is a comparison for of costs for coastal protection works versus planned retreat to respond to coastal inundation. Readers will readily find information online to explore the predicted impacts of sea level rise for their own contexts[ii].In response to sea level rise Christians can be prepared to demonstrate kindness and compassion towards vulnerable peoples. We can extend practical assistance to poorer communities adversely affected by sea level rise, because those with the resources to move will head to higher ground. There is still time to show love for our neighbours by choosing to lower our own carbon footprints, and to encourage those who will struggle with hard decisions arising from the impacts of sea level rise.
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