Eco-efficiency, the breakthrough
Eco-efficiency is defined as the ratio between environmental gains and the costs associated with achieving the gain. It had been applied to recycling before 2003 (see chapter 7.5) but since good and complete environmental metrics on recycling were lacking, this work had limited significance. This all changed with the QWERTY approach (see chapter 7.4). But how to present results of Eco-efficiency calculations in a transparent way? Through figures and/or ratios alone? The problem of Eco-efficiency is a ratio; if either the numerator (the environmental effect) or the denominator (the cost) would be near zero, there is either no distinction at all or indefinitely high numbers come into play. Maybe this is the reason why traditional environmentalists have avoided ratios and almost exclusively stick to absolute numbers. Moreover, if the recycling does not represent a cost but brings a yield (or if the environmental effect of recycling is negative instead of positive), the ratio representation brings difficulties too. How to deal with such ‘changes in sign’? Jaco and I have been struggling with this issue for many hours. Finally we came to diagrams in which environmental effects were represented on the X-axis and money by the Y-axis diagram. The baseline situation (the situation before the recycling action, for instance landfill of electronic waste) which represents an certain environmental effect and a certain cost too is supposed to be located at the origin of the diagram. What is plotted is the relative change after the action, both in environmental and monetary terms. In this way there are four possible results: environmental gains combined with monetary gains, environmental gains at the cost of money, monetary gains at the cost of the environment and environmental losses combined with monetary losses.(see chapter 7.5) Vector diagrams turned out to be to very powerful in analyzing take-back and recycling. First of all it showed that for various product types (plastic dominated products, glass dominated products, metal dominated products, precious metal dominated products) the eco efficiency of recycling is very much different. This has important consequences in rule making (see chapter 8.3.1).
国际会议
The 4th International Conference on Waste Management and Technology(第四届固体废物管理与技术国际会议)
北京
英文
417
2009-11-28（万方平台首次上网日期，不代表论文的发表时间）