Sea levels are projected to rise by 38-77cm by the end of this century, threatening hundreds of millions of coastal residents worldwide. Sea level rise is compounded in many cases by rapid coastal development, chronic land subsidence, and increasingly destructive storms. In Indonesia and the Philippines, for example, 40 million and 13 million people, respectively, live in low-elevation coastal zones. Sinking cities like Jakarta, Semarang, and Manila are experiencing significant coastal erosion. Accordingly, coastal adaptation, or the process of preparing communities to endure increasingly severe coastal flooding, is urgently important for many city governments.

Indonesia and the Philippines offer a valuable opportunity to study coastal adaptation because strategies vary strikingly across cities in both countries. Their decentralized systems of governance empower cities to make their own policies, and the high risk of flooding ensures that they do. As a result, experiments with seawalls, land reclamation, mangrove reserves, and managed retreat, among other policies, are unfolding at the local level. In short, these neighboring archipelagoes have become testing grounds for coastal adaptation.

This project collaborates with community-based organizations in Indonesia and the Philippines to document coastal adaptation strategies across cities. The data that we collect will not only enable critical assessments of specific adaptation policies, but also facilitate comparative analysis, contributing to theorizing about the conditions that are associated with different adaptation outcomes.

PI & Co-PI: Ryan Tans & Douglas Kammen

Funding Agency: Yale-NUS College
Project Duration: 1 January 2024 – 30 June 2026