Coastal zones and urbanization: a wake-up call

Coastal zones have been sites of human settlement for centuries, their ports providing a gateway to the wider world and their fertile soils allowing people and agriculture to thrive. Today as in the past, economic activity and access to water resources continue to attract people to coastal cities, with many of world’s major cities located in ocean coastal zones.

However, recent research shows that coastal cities are today facing serious and increasing risks associated with climate change, with a 2013 report (Hallegatte et al.) predicting that coastal cities can expect a nine-fold increase in flooding by 2050.

Whilst many reports have focused on the natural risks associated with climate change, such as storm flooding, the impact and destructive potential of these risks is largely driven by social changes, as people and economic activities are increasingly concentrated in coastal cities.

Despite this, there is a lack of action in development policy and planning practices relating to coastal cities, says a report published this month by the Land-Ocean Interactions in the Coastal Zone Project (LOICZ), and The Urbanization and Global Environmental Change Project (UGEC). Asian coastal cities top the lists of potential losses due to flooding, but a ‘business as usual’ mindset in development and planning persists, say the authors. This report is a wake-up call.

Urbanization in coastal zones is a relatively new area for study, but the ‘future is already being felt’ by those living in cities on the coast, where impacts include accelerated subsidence, diminished water quality, pollution and vulnerability of coastal wetlands and coral reefs.

There is no ready-made solution to challenges in coastal zones, and what works in one city may be infeasible in another, but several successful adaptive strategies to reduce risks and impacts are highlighted. These include considering managed ‘retreat’ from coastlines, and community action to support adaptation and reduce vulnerability.

Overall, the authors emphasize the importance of taking a combined approach to the challenges, including hard engineering (such as breakwaters), natural approaches (such as the planting of mangroves to promote coastal resilience), technology (such as early warning systems for floods), and legislative and policy approaches to build-in resilience in new developments.