The Environmental Relevance of Capital Goods in Life Cycle Assessments of Products and Services

Abstract

Goal and Scope. Many life cycle assessment case studies neglect the production of capital goods that are necessary to manufacture a good or to provide a service. In ISO standards 14040 and 14044 the capital goods are explicitly part of the product system. Thus, it is doubtful if capital goods can be excluded per se as has been done in quite a number of case studies and LCA databases. There is yet no clear idea about if and when capital goods play an important role in life cycle assessments. The present paper evaluates the contribution of capital goods in a large number and variety of product and service systems. A classification of product and service groups is proposed to give better guidance on when and where capital goods should be included or can be neglected. Methods. The life cycle inventory database ecoinvent data v1.2 forms the basis for the assessment of the environmental importance of capital goods. The importance is assessed on the basis of several hundreds of cradle-to-gate LCAs of heat and electricity supply systems, of materials extraction and production, of agricultural products, and of transport and waste management services. The importance within product (and service) groups is evaluated with statistical methods by comparing the LCA results including and excluding capital goods. The assessment is based on characterised cumulative LCI results using the CML baseline characterisation factors of the impact categories of global warming, acidification, eutrophication, human toxicity, freshwater acquatic toxicity, terrestrial ecotoxicity, ionising radiation, and land competition, based on proxy indicators (fossil and nuclear) cumulative energy demand, and based on the endpoint indicators Eco-indicator 99 (H,A) mineral resources, human health, eco system quality and totals.