تصاحب اکوسیستم توسط هنگ کنگ و پیامدهای آن برای توسعه پایدار

The Hong Kong Special Administrative Region is a highly developed modern city where technical and economic advances have made it possible to support 7 million people on 120 km2 of built-up land, resulting in 58 000 people per km2, one of the highest population densities in the world. This population depends on a continual supply of materials, energy and information to function, and these resources are mainly supplied from outside Hong Kong's own geographical boundaries. The ecological footprint (EF) of Hong Kong due to its direct and indirect consumption of renewable resources and waste generation is presented. Additionally, the paper traces the spatial patterns of Hong Kong's EF and examines the implications of this ecosystem appropriation. The study finds an EF for Hong Kong of about 6 ha per capita, with the largest appropriation occurring for marine ecosystems. If the impacts of fish farming are included, Hong Kong appropriates a marine area nearly 2000 times its own built-up city area. Current resource consumption and waste generation patterns in Guangdong, China — where much of Hong Kong's terrestrial ecosystem appropriation occurs — are also discussed.

The Hong Kong Special Administrative Region (SAR) is a dense, highly developed metropolitan area in southern China. Hong Kong supports 7 million people on as little as 120 km2 of built-up land (excluding open space and vacant development property) with one of the highest population densities in the world (58 000 people per km2 built-up land). Like other cities, Hong Kong requires productive ecosystems for food, water and other basic necessities (Newcombe et al., 1978 and Boyden et al., 1981). While Hong Kong supplies some of these requirements, it depends heavily upon ecosystems outside its own borders for resources and waste assimilation. The concept of an ecological footprint (EF), as articulated by Rees and Wackernagel, 1994, Wackernagel and Rees, 1996 and Folke et al., 1997, provides a quantitative (albeit static) measure of this use, or appropriation, of external ecosystems and their resources. An EF reflects not only the direct impacts of food and material consumption, but also the indirect, or ‘hidden,’ ecosystem support required to sustain a city's population (Folke et al., 1997). By making this support explicit, an EF enables policy-makers and consumers to visualize, measure and compare their city's environmental impact and appropriation of other areas’ resources and ecosystems. Such comparisons have been carried out for a number of countries and regions (Wackernagel et al., 1999a and Wackernagel et al., 1999b), most recently in the World Wide Fund for Nature's (WWF) Living Planet Report (World Wide Fund for Nature, 2000). In this paper, we estimate Hong Kong's direct and indirect ecosystem appropriation and environmental impacts from resource use and waste discharges. The paper's main objective is to present a new dimension in EF methodology: identifying the spatial patterns of environmental demands through ecosystem appropriation. In order to do so, the paper first estimates the area of agricultural land, marine ecosystems, and forests appropriated (the ‘EF’) by Hong Kong for annual wood, fiber, paper, water and food consumption, and assimilation of CO2 emissions. We then analyze the location from which some parts of the EF (e.g. certain food items and drinking water) are appropriated or to which certain pollutants (e.g. nitrogen) are discharged. Finally, we compare the EFs and consumption patterns of Hong Kong with its neighbor, Guangdong Province, China.

Hong Kong is a modern urban system highly dependent upon external ecosystems for its food, material resources and waste assimilation. Our study shows that the SAR appropriates 2200 times its built-up land to sustain the consumption of its current population. This equates to an EF of nearly 4 ha per capita (excluding fossil fuel emissions) or 5–7 ha per capita, if fossil fuel use is included. Of this EF, almost all is located outside Hong Kong, with over 30% (excluding energy) occurring in China (mainly Guangdong) and 60% in other countries or areas of the world. The EF comparisons in this article highlight some of the limitations of this method as a means for assessing cities’ environmental impacts and sustainable development (van Vuuren and Smeets, 2000). On the negative side, EFs can contribute to conflicting perspectives on the scope of a city's impacts. For example, in the preceding case for Guangzhou, an EF analysis reveals that a much smaller area is required by Guangzhou than Hong Kong to sustain its population, but this result masks the incredible stress placed on Guangzhou's local environment to accommodate rising living standards. If additional environmental data are examined (Guangzhou EPB, unpublished data), it can be seen that, by 1995, per-capita freshwater use, wastewater discharges and solid waste generation rates in Guangzhou exceeded those of Hong Kong in 1997, while air emissions were quickly attaining similar levels — an unanticipated result given the much lower per-capita EF. These high per-capita pollution loads put significant pressure on the regenerative capacity of Guangzhou's natural air, land and water systems. Therefore, EF analysis should be viewed as only one of a host of tools available to policy-makers to gauge their city or region's sustainability (Rees, 2000). Despite the shortcomings, EFs can provide insights not readily apparent from other environmental analyses, highlighting the often hidden consequences and spatial patterns of ecosystem appropriation. What our study suggests is that the location of the footprint matters — in other words, where is as important as how much. For example, in typical discussions of cross-border (i.e. Hong Kong and China) issues, Guangdong's negative environmental impacts on Hong Kong are usually emphasized, with the reverse situation frequently overlooked. But, as our EF analysis demonstrates, indirect environmental impacts from Hong Kong's consumption may be substantial, with N-discharges in Guangdong nearly equivalent to of a population of over 5 million Hong Kong people. Indeed, the N-wastes (for food production, excluding human sewage) discharged outside of Hong Kong's borders are 30 times larger than those released within the SAR itself. Therefore, at least part of the water pollution arriving downstream from Guangdong is actually caused by Hong Kong consumers (e.g. for food) and businesses (e.g. relocation of factories to Guangdong), and this situation should be considered during cross-border talks on water quality, wastewater treatment and local development. Our EF analysis also reveals that Hong Kong's resource consumption affects not only nearby China, but also regional ecosystems. For example, Hong Kong obtains over 95% of its annual seafood supply from outside its own marine waters, and this appropriation creates serious environmental impacts. Consider the case of coral reef fish supply. Each year, Hong Kong consumes about 3 kg per capita of coral reef fish, which are mainly caught in Southeast Asia and the Pacific, and sold to Hong Kong (and China) through a ‘live reef fish trade’ (Johannes and Riepen, 1995 and Lau and Parry-Jones, 1999). For over a decade, this trade has employed destructive fishing practices (e.g. cyanide) and overexploited certain reef fish species, placing significant negative pressure on coral reefs and fisheries resources in the Indo-Pacific (Barber and Pratt, 1998). Despite its major role in the live reef fish food trade, neither the public nor the Hong Kong government have acknowledged the deleterious impacts their seafood consumption and trade activities have on external marine ecosystems, or the central importance these systems play in their own economy and survival. The lack of awareness (or denial) by consuming countries that they hold some share of responsibility for conserving and maintaining the health of ecosystems outside their own jurisdiction is not unique to Hong Kong. Nevertheless, if Hong Kong is ever to achieve its stated goal of becoming a ‘truly sustainable city,’ its appropriation of marine and terrestrial ecosystems, whether at the local, regional or global levels, must be explicitly accounted for and reduced by both consumers through their consumption patterns and by the government in its trade and economic policies.