基于等价分析法评估溢油事故的自然资源损害

尽管国际公约和许多国家立法已将海上溢油事故导致的自然资源损失列入索赔范围,然而,在量化和货币化损害以及确定索赔和修复范围等方面尚未建立被广泛接受的计算方法。生境等价分析(Habitat Equivalency Analysis,HEA)和资源等价分析(Resource Equivalency Analysis,REA)是美国和欧盟应用于评估自然资源损害的理论方法,二者的关键假设是受损的生态服务损失和修复计划的服务收益应当相等。HEA结果依赖于生态服务价值标尺选择、服务价值水平、恢复曲线形状、修复计划时长以及贴现率等;REA结果受死亡生物数量和年龄组成的影响。HEA和REA的非货币形式结果补偿的并非生态环境,而是人类社会福祉。目前,一些货币化损失的方法已被提出,然而传统经济学家和生态经济学家之间存在争议。美国部分法庭承认HEA和REA方法,其结果为法庭索赔提供数据支持。如果将生态学和经济学原理结合考虑,将能够促进等价分析法的深入发展,推动索赔工作更加有理有据。

The Assessment of Natural Resource Damages Caused by Oil Spill Incidents based on Equivalency Analysis Methods

Although the international conventions and laws of many countries have included the ecological damages and natural resource losses resulting from marine oil spill incidents into claim scope recently, acceptable approaches have not established wordwide to quantify the ecological losses caused by pollution, scale the sizes of damage and compensation and convert the restorative ecological compensation into economical damage estimates. Habitat Equivalency Analysis (HEA) and Resource Equivalency Analysis (REA), two popular approaches in US and Europe, were reviewed and discussed in detail. The key assumption of these two approaches was that the ecological service losses of injured habitats (or resources) should be equal to those supplied by the restorative projects. HEA which was on the basis of service-to-service approach strongly depended on several parameters, including the choices of ecological service metrics, service levels, the shape of recovery curves, the lengthens of restoration plans, and discount rates. REA which was the upgrade of HEA was impacted by the amounts of dead wildlife and their age classes. Both of the non-monetary results of HEA and REA compensated the human welfare losses rather than the eco-environment and natural resources. As so far, variety of monetization methods of HEA and REA were developed by economists, but widely arguments were triggered by traditional economists and eco-economists. Nevertheless, some US courts upheld HEA and REA as appropriate measures to determine the scale of compensatory restoration projects. Furthermore, the restoration costs derived from HEA and REA supplied data support for settlements out of courts. In the long run, combining the ecological and economical principles is promising to promote the development of equivalency analysis deeply and widely so as to make the claim rational and legal valid.