School of Forestry and Environmental Studies, Yale University, 195 Prospect Street, New Haven, CT 06511, USA.
Philos Trans A Math Phys Eng Sci. 2013 Jan 28;371(1986):20120002. doi: 10.1098/rsta.2012.0002. Print 2013 Mar 13.
Material efficiency--using less of a material to make a product or supply a service--is gaining attention as a means for accomplishing important environmental goals. The ultimate goal of material efficiency is not to use less physical material but to reduce the impacts associated with its use. This article examines the concept and definition of material efficiency and argues that for it to be an effective strategy it must confront the challenges of operating in a multi-material world, providing guidance when materials are used together and when they compete. A series of conceptions of material efficiency are described, starting with mass-based formulations and expanding to consider multiple resources in the supply chain of a single material, and then to multiple resources in the supply chains of multiple materials used together, and further to multiple environmental impacts. The conception of material efficiency is further broadened by considering material choice, exploring the technical and economic effects both of using less material and of materials competition. Finally, this entire materials-based techno-economic system is considered with respect to the impact of complex policies and political forces. The overall goal here is to show how the concept of material efficiency when faced with more expansive--and yet directly relevant--definitional boundaries is forced to confront analytical challenges that are both familiar and difficult in life cycle assessment and product-based approaches.
材料效率——使用较少的材料来制造产品或提供服务——作为实现重要环境目标的一种手段正受到关注。材料效率的最终目标不是使用较少的物质材料，而是减少其使用带来的影响。本文探讨了材料效率的概念和定义，并认为要使其成为一种有效的策略，它必须应对在多材料世界中运作的挑战，为材料的协同使用和竞争提供指导。本文首先描述了一系列材料效率的概念，从基于质量的配方开始，扩展到考虑单个材料供应链中的多种资源，然后扩展到一起使用的多种材料的供应链中的多种资源，再扩展到多个环境影响。通过考虑材料选择，探讨了使用较少材料和材料竞争的技术和经济影响，进一步拓宽了材料效率的概念。最后，考虑到复杂政策和政治力量的影响，对整个基于材料的技术经济系统进行了考虑。这里的总体目标是展示当材料效率的概念面临更广泛——但直接相关——的定义边界时，如何被迫面对在生命周期评估和基于产品的方法中既熟悉又困难的分析挑战。
