Farley Joshua
Community Development and Applied Economics, 205B Morrill Hall, The University of Vermont, Burlington, VT 05405-1708, USA.
Conserv Biol. 2008 Dec;22(6):1399-408. doi: 10.1111/j.1523-1739.2008.01090.x.
Until recent decades, economic decision makers have largely ignored the nonmarket benefits provided by nature, resulting in unprecedented threats to ecological life-support functions. The economic challenge today is to decide how much ecosystem structure can be converted to economic production and how much must be conserved to provide essential ecosystem services. Many economists and a growing number of life scientists hope to address this challenge by estimating the marginal value of environmental benefits and then using this information to make economic decisions. I assessed this approach first by examining the role and effectiveness of the price mechanism in a well-functioning market economy, second by identifying the issues that prevent markets from pricing many ecological benefits, and third by focusing on problems inherent to valuing services generated by complex and poorly understood ecosystems subject to irreversible change. I then focus on critical natural capital (CNC), which generates benefits that are essential to human welfare and have few if any substitutes. When imminent ecological thresholds threaten CNC, conservation is essential and marginal valuation becomes inappropriate. Once conservation needs have been met, remaining ecosystem structure is potentially available for economic production. Demand for this available supply will determine prices. In other words, conservation needs should be price determining, not price determined. Conservation science must help identify CNC and the quantity and quality of ecosystem structure required to ensure its sustained provision.
直到最近几十年，经济决策者在很大程度上忽视了自然所提供的非市场效益，给生态生命支持功能带来了前所未有的威胁。当今的经济挑战在于决定多少生态系统结构可转化为经济生产，以及必须保留多少以提供基本的生态系统服务。许多经济学家和越来越多的生命科学家希望通过估算环境效益的边际价值，然后利用这些信息来做出经济决策，从而应对这一挑战。我评估这种方法，首先是通过审视价格机制在运转良好的市场经济中的作用和有效性，其次是找出阻碍市场为许多生态效益定价的问题，第三是关注对由复杂且了解甚少、正经历不可逆转变化的生态系统所产生的服务进行估值时所固有的问题。然后，我将重点放在关键自然资本（CNC）上，它产生的效益对人类福祉至关重要，而且几乎没有替代品。当迫在眉睫的生态阈值威胁到关键自然资本时，保护至关重要，边际估值就变得不适用了。一旦满足了保护需求，剩余的生态系统结构就有可能用于经济生产。对这种可用供给的需求将决定价格。换句话说，保护需求应该决定价格，而不是由价格决定。保护科学必须有助于确定关键自然资本以及确保其持续供应所需的生态系统结构的数量和质量。
