Managed retreat for climate change adaptation in coastal megacities: A comparison of policy and practice in Manila and Vancouver.

'Managed retreat' is gaining considerable attention as part of megacities' climate change adaptation and resilience enhancement toolkits, and as a policy option for disaster risk reduction in coastal regions. The overarching objective of managed retreat is to reduce the exposure of people and assets to flooding, storm surges and sea level rise by retreating from these threats in a planned fashion. Managed retreat is one of four main options covered in the 'PARA' (protect/accommodate/retreat/avoid) framework explained in this paper, which can be used to enhance resilience in coastal megacities. In this paper, qualitative research methods were used to collect primary data on the feasibility of using managed retreat for two case study coastal megacities: Manila, Philippines, and Vancouver, Canada. Both case studies review the risk context of each city, local climate change adaptation/disaster risk reduction (CCA/DRR) policies linked to managed retreat, examples of managed retreat practice, and barriers to managed retreat identified through primary or secondary data analysis. Comparisons between the two cases are then carried out, and similarities and differences are highlighted. The paper concludes by suggesting possible means by which barriers to managed retreat might be overcome.