Coastal Cities at Risk: How will they adapt to converging climate change impacts?

Low-lying coastal mega-cities, many built on river deltas, are growing rapidly in terms of population and infrastructure asset value and play a pivotal role in the global economy. Global seaborne trade has more than doubled in the past 30 years and, as Hurricane Katrina demonstrated, the effect of a major storm on a port city such as New Orleans can be socially, economically and ecologically devastating. As coastal cities experience increased population growth, urban development and economic activity, the risk of climate change impacts rise simultaneously.

ACT is a research partner in the International Development Research Council-funded “Coastal Cities at Risk (CCaR): Building Adaptive Capacity for Managing Climate Change in Coastal Megacities” research project. This five-year initiative focuses on major coastal cities that are vulnerable to the combined climate change risks of sea-level rise, storm surges with coastal flooding and riverine flooding.

The project twins a national team of Canadian researchers, led by ACT Extreme Weather author and Policy Chair for the Institute for Catastrophic Loss Reduction, Dr. Gordon McBean, with experts in Bangkok, Manila and Lagos. The team selected Metro Vancouver as the Canadian location for study. All four cities face high coastal flood risks based on physical infrastructure exposure and socio-economic vulnerability to climate extremes, storm surges and the effects of sea level rise. They also demonstrate a range of social, cultural, political and economic characteristics that will render the research findings relevant and transferable to other cities.

In a 2007 OECD report, Nicholls et al. ranked the world’s large port cities with high physical exposure and socio-economic vulnerability to climate impacts such as sea level rise, coastal flooding, storm surge, high winds, subsidence, population growth and urbanization. The report lists Bangkok among the top ten delta cities presently at risk, with Manila as the seventh largest vulnerable to wind damage. Based on climate change and growth projections, Lagos will likely have the most population exposed to coastal inundation in Africa. In Canada, the Metro Vancouver region is most at risk from sea-level rise, storm surges and river floods.

One of the fundamental questions that this project aims to answer is: How will mega-cities successfully adapt to, and when necessary cope with, risks posed by the effects of climate change, including sea level rise, in the context of urban growth and development?

It is important to note that exposure can be significantly reduced if protection measures are put into place. For instance, there are many ways in which flood and wind vulnerability can be addressed. Nevertheless, even high protection levels can fail, which means that over time, large exposure in terms of population and assets is likely to translate into more frequent city- or regional-scale disasters.

The policy implications suggest that it is critical to engage in proactive, advance climate change adaptation approaches in both coastal flood risk management and urban development planning to minimize risk and increase resilience. Failure to do so will likely have regional, national and even global consequences.

An Economy and Environment Program for Southeast Asia (PDF) conference in 2008 concluded that the adaptive capacity of both local communities and national governments is limited, and that climate change adaptation research should focus on vulnerable populations and the needs of those who actually use research, such as policy makers and civil society. Furthermore, research should facilitate action on the ground in order to increase the capacity of the most vulnerable communities to adapt.

The CCaR program incorporates the above conclusions by acknowledging that it is a priority to develop disaster resilient cities and adaptation strategies where the focus is on the most vulnerable regions and populations. Project outcomes will include guidelines for better-planned, safer cities in which decision makers have access to the tools they need to reduce vulnerability through effective adaptation.

The CCaR project runs until March 2016. One of the first deliverables is an ACT literature review (PDF) on past and projected sea level rise for the Metro Vancouver region.

by Yaheli Klein
ACT Research Assistant


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