Using life-cycle analysis

Life cycle analysis is a technique to quantify the energy and raw material consumed and the liquid, solid and gaseous waste generated at each stage in the life of a product or service, a process known geenrically as "from the cradle to the grave". It encompases extraction of raw materials, production, distribution and use to final dispoal recylcing and composting.

Life cycle analysis (LCA) involves an element of subjective judgement about where to set the boundaries of what is regarded as the product's life. Comprehensive LCA is time-consuming, expensive and data-intensive. A more "scoped" approach is to focus attention on the main environmental impact of the product.

The recent emergence in many countries of a more environmentally conscious consumer public, combined with increased interest on the part of some industries in providing environmentally sound consumer products, is a significant development. Governments and international organizations, together with the private sector, should be encouraged to develop criteria and methodologies for the assessment of environmental impact and resource requirements throughout the full life cycle of products and processes. Results of those assessments would be transformed into clear indicators in order to inform consumers and decision makers.

This strategy features in the framework of Agenda 21 as formulated at UNCED (Rio de Janeiro, 1992), now coordinated by the United Nations Commission on Sustainable Development and implemented through national and local authorities.

An analysis by IIASA of different types of electric light bulbs took into account the total energy consumption and costs of every stage in the electricity supply chain: the fuel extraction and supply, electricity generation, electricity transmission, and running the light bulb itself. It found that costs to deliver the same service could differ by about 30%, while carbon dioxide (CO2) emissions to provide that service could differ by more than 90% and primary energy use by 75%. For example, per lumen-year, a standard incandescent bulb, powered by electricity from a conventional coal-fired power station in the USA, cost only fractionally more than a compact fluorescent bulb four times its purchase price, but run from a modern combined-cycle natural gas turbine with carbon scrubbing. The compact fluorescent bulb had 25% of the primary energy demand of the incandescent bulb and less than 10% of its CO2 emissions. So cost savings bore little relationship to environmental and resource savings. In addition, the differences in energy consumption were almost entirely on account of the different bulbs, whereas the CO2 savings were divided between the effect of cleaner fuel and the more energy efficient light bulb.