Chongming Island, a large island off the Shanghai Coast, is China's first and only endorsed eco-island. The Chinese central government and the Shanghai provincial government have placed high bets on making Chongming a world-class example of sustainable urbanization and involved the United Nations Environmental Programme (UNEP) for valuable knowledge transfer. However, to what extent is it feasible to preserve the green, open and natural character of the island given the enormous urbanization pressure Shanghai faces? In this contribution, the authors examine to what extent the lofty goals formulated in the various national, provincial and local plans are effectively implemented. They claim that existing assessments are useful, but rely too heavily on technocratic indicator systems to allow for insights regarding on the ground implementation. They analyse existing assessment studies on eco island development, but then develop a broader planning and policy oriented assessment matrix of their own which they apply in an independent field study. They find that the Shanghai and Chongming authorities are generally taking their eco island development task seriously through restricting urban development to certain locations, opening eco-parks, developing an integrated water system, and invest substantial resources into making it happen. However, a sustainable public transport system is still missing and at a few locations commercially attractive to real estate development villa parks and skyscrapers have emerged. By synthesizing data from existing evaluations with information retrieved following the format of their assessment matrix, an analysis of the eco island's implementation which connects more closely with the situation experienced on the ground has been generated.

Over the last few decades, China has seen a steep rise in diverse eco city and low carbon city policies. Recently, attention has begun to focus on the perceived shortcomings in the practical delivery of related initiatives, with several publications suggesting a gap between ambitious policy goals and the emerging realities of the newly built environment. To probe this further, in this article we examine – based on the policy network approach – how the gap between high-level national policies and local practice implementation can be explained in the current Chinese context. We develop a four-pronged typology of eco city projects based on differential involvement of key (policy) actor groups, followed by a mapping of what are salient policy network relations among these actors in each type. Our analysis suggests that, within the overall framework of national policy, a core axis in the network relations is that between local government and land developers. In some cases, central government agencies – often with buy-in from international architecture, engineering and consulting firms – seek to influence local government planning through various incentives aimed at rendering sustainability a serious consideration. However, this is mostly done in a top-down manner, which overemphasizes a rational, technocratic planning mode while underemphasizing interrelationships among actors. This makes the emergence of a substantial implementation gap in eco city practice an almost predictable outcome. Consequently, we argue that special attention be paid in particular to the close interdependency between the interests of local government actors and those of land and real estate developers. Factoring in this aspect of the policy network is essential if eco city implementation is to gain proper traction on the ground.