LEARNING TO LIVE With LIFE CYCLE ASSESSMENT

May 30, 2012 - Implicit prioritization in life cycle assessment: text mining and detecting metapatterns ... Chemical Engineering Science 2001 56 (8), ...
22 downloads 0 Views 3MB Size
hat makes a "green produ c t " ? Reduced emissions from a particular process in its manufacture? The incorporation of recycled materials? The elimination of chlorine or some other "bad actor"? The answer is sometimes all these things, sometimes none. Products have environmental impacts over the course of their existence, from extraction and procurement of raw materials to manufacturing, distribution, use, and disposal. Determining what is green or even what is environmentally preferable is a complex business, and the boundaries of such an assessment cannot be drawn at the factory door. One tool receiving increased attention in response to this complex assessment problem is life cycle assessment (LCA). LCA is a tool used to identify and measure both "direct" and "indirect" environmental, energy, and resource impacts associated with a product or process. Direct impacts might include emissions and energy consumption of a manufacturing plant; indirect impacts include energy use and impacts caused by extraction of raw materials used to make the product, product distribution, consumer use, and disposal.

ES&T

W

L E A R N I N G TO LIVE With

LIFE CYCLE ASSESSMENT

Private sector use of life cycle assessment is growing rapidly, especially in Europe, where 130 LCA studies were conducted last year. The November 1993 conference at the Massachusetts Institute of Technology, "Life Cycle Assessment: From Inventory to Action," examined practical lessons learned from LCA and addressed LCA theory, methodology, and regulatory implications. Findings from the conference suggest new directions for corporate practice and public policy, as well as strengths and weaknesses of this tool. LCA findings One lesson from several of the LCAs discussed at the conference is that indirect impacts, particularly postmanufacturing ones, often dwarf direct impacts. The American Fiber Manufacturers Association (AFMA), for example, conducted an LCA of an " a v e r a g e " polyester blouse and found that far more resources were used by consumers in washing and drying the blouse than were used in its manufacture. This lesson, and similar ones, point to a new direction for corporate environmental practice: Firms wishing to improve the environ-

BY

J E N N I F E R N A S H A N D MARK D. S T O U G H T O N

mental performance of their products may need to design them to reduce postmanufacturing impacts. Robert Baker, t h e AFMA speaker, noted that the redesign of fibers for effective cold-water w a s h i n g m a y be the next step for member companies. This change could substantially r e d u c e energy c o n s u m p t i o n over the life of a polyester product. A s e c o n d lesson brought out b y conference d i s c u s s i o n s is that, when indirect impacts are taken into a c c o u n t , " c o n v e n t i o n a l w i s d o m " about t h e environment—for example, t h e " r e d u c e , reuse, recy-

236 A Environ. Sci. Technol., Vol. 28, No. 5, 1994

cle" hierarchy—may no longer a p p l y . Several s p e a k e r s n o t e d t h a t recycling may consume more resources than it saves, if, for example, recyclables must be transported long d i s t a n c e s for p r o c e s s i n g or sale. Reducing toxicity m a y result in environmental costs if, for example, switching from chlorinated to water-based solvents requires increased energy u s e a n d generates additional solid waste. LCA a n d regulation In Europe a n d t h e United States, interest in LCA as a regulatory tool

0013-936X/94/0927-236A$04.50/0 © 1994 American Chemical Society

is growing. The European Commission is planning to use life cycle studies as the basis for packaging recovery and recycling targets. The recently developed Belgian "eco-tax" will be levied on products based on results of LCA studies. The European Commission will use LCA as the basis for awarding "eco-labels" to all products sold in Europe (including products manufactured elsewhere). This EC-wide approach will replace the national green labels of France, Germany, and other countries that were not based on LCA and often were awarded on the basis of a single environmental criterion. In the United States, EPA indicates it has no plans to require companies to conduct LCAs. It is likely, however, that in the future the federal government will use LCA approaches to guide some of its act i o n s . For e x a m p l e , a draft executive order requiring federal procurements to be of "environmentally preferable products" will probably use life cycle studies to define "environmentally preferable." EPA is studying the life cycle impact of a solvent degreasing standard proposed under the Clean Air Act. Problems impede use Although acceptance of LCA is growing, many conference participants noted little support for conducting life cycle studies in their organizations. Methodological and conceptual problems contribute to this, particularly the lack of a fully articulated LCA methodology. And regardless of the exact procedure followed, a "full" LCA would seem to demand a data set whose size and reliability requirements present serious problems: One LCA discussed required 600,000 data points, and the data available are often proprietary or unreliable. LCA practitioners thus must make assumptions about how to set the boundaries of their study, assess the quality of the data, and address data gaps and other deficiencies. Few conventions exist to guide them. On a more conceptual level, LCA can present problems when it becomes more than a purely internal instrument to the firm. When firms use LCAs to promote their products as "green" for marketing or regulatory advantage, they may subject themselves to intense scrutiny and attack by competitors, the government, or environmental advocacy groups. Advocacy groups in partic-

ular may feel that the complexity of LCA and the amount of data it involves obscure fundamental issues of environmental ethics and exclude the public from making decisions about the environment. Another problem involves the assumptions implicit in any LCA study when that study has implications outside the firm that produced it. When used at its full potential, LCA can be a tool to improve environmental performance across a product's entire life: It is an opportunity for firms to influence the environmental practices of other players in the life cycle chain. McDonald's Restaurants, for example, has used the results of its life cycle study of packaging to set the tone and direction for its suppliers. McDonald's will require suppliers to provide unbleached food wraps with a middle layer of recycled paper, which company life cycle studies have found to be environmentally beneficial. But using LCA in this way, particularly when its findings are contrary to conventional environmental wisdom, raises questions of legitimacy: Who has a "stake" in certain outcomes of the LCA? Which data should be used? Where should the boundaries of the study be drawn? In spite of these difficulties, however, the consensus of the conference was that LCA is a tool with great potential for improving environmental performance. And even though problems do exist, the process of thinking through ways to make do with incomplete methodology and data can itself be a valuable learning exercise.

EPA CONTAMINANT STANDARDS... AVAILABLE FROM ISOTEC INC.

Isotec is the exclusive a g e n t in

the USA for C h e m s y n Science L a b s / W e i l i n g ton Labs a n d is m a r k e t i n g their lines of E n v i r o n m e n t a l Contaminant Standards. Dioxins. Furans, M e t h y l a t e d D i o x i n s a n d Furans, a n d other compounds are now in stock. Isomers of: • Chlorinated Dibenzo-p-Dioxins • Chlorinated Dibenzofurans • Brominated Dibenzo-p-Dioxins • Brominated Dibenzofurans

Jennifer Nash is a research associate at the Massachusetts Institute of Technology's Technology, Business, and Environment Program. Her research explores tools and strategies companies use to promote learning and change. Mark D. Stoughton is a graduate student in MIT's Technology and Policy Program. His focus is on environment and sustainable development, with particular attention to issues of technol-

ogy and public choice.

are available with stable isotope labels, radioisotope labels, or unlabellea. W e also welcome inquiries for custom synthesis jobs.

ISOTECH INC. A i»tattte»on·, USA Company

Stable Isotopes For Research & Industry 3858 Benner Road, Miamisburg, OH 45342 (513)859-1808 (800)448-9760 Telex: 288278 FAX: (513) 859-4878 REFER TO KEY NO. 2

Environ. Sci. Technol., Vol. 28, No. 5, 1994 237 A