Islands are known to be vulnerable to many natural and anthropogenic hazards, especially estuarine islands, which are affected at rates and intensities above those found elsewhere around the globe. The sustainable development of estuarine islands has been a part of their evolution, which has been a continuous integration of human impact and response to natural processes. This study reviews the complex dynamics of Chongming Island, an estuarine island in Shanghai, with an emphasis on the nature of human intervention. We conclude that the island is an example of a coupled human-environment system, as it has been throughout its formation and evolution, which is integrated at the local (intracoupled), regional (pericoupled), and global (telecoupled) scale. This conceptual framework reveals Chongming Island to be an exemplar of—and indeed a test-case for—China’s vision of eco-civilization development, in which it is reimagined as an ‘eco-island’. Accordingly, we argue that islands are benchmarks for building sustainability in the Anthropocene, and a more complete understanding of their dynamics, and the factors that influence them in a metacoupled world, is critical for future development.