What are LCAs?

Posted by: Amy

An LCA, or a Lifetime Cycle Assessment, is a multi-leveled process of calculating the lifetime environmental impact of a product or service. LCAs are a component of Environmental Product Declarations, or EPDs. LCAs are about energy, or a product's carbon footprint. The criteria for LCAs are: global warming, acidification, photochemical oxidation, stratospheric ozone depletion, human toxicity, freshwater aquatic ecotoxicity, marine aquatic ecotoxicity, eutrophication, land use, ecosystem damage, terrestrial ecotoxicity, abiotic resource depletion, non-hazardous waste landfill, radioactive waste landfill, and hazardous waste landfill. The process, according to guidelines set by the ISO, the International Organization for Standardization, includes definition and scope of goals, analysis, impact assessment and interpretation. After each of these steps, iteration is also required; thus, each step is continuously redefined. Since the process depends heavily on the definition and scope of goals taken on for each individual assessment, the variety of findings for one product by several different analysts can vary widely. When undertaking an LCA assessment, it's wise to use caution for that same reason. In the first step of an LCA analysis, the life cycle of a product must be defined. Any number of different analysts may define that life cycle differently. When talking about LCAs, "cradle" refers to the acquisition of fossil fuel materials in the beginning of the products life cycle. Three popular life cycles are: cradle-to-gate, Cradle-to-grave, and cradle-to-cradle. Cradle-to-gate stops after the product has been used, cradle-to-grave stops after the product is disposed of, and cradle-to-cradle, the most comprehensive, goes all the way through product recovery, after that product is used and recycled, where applicable. In the second step, the life cycle inventory, data is collected, that data is assigned to different processes, calculations are made and the functional units of a products are related to the different datum collected. The third step, impact assessment, involves the analysis of the data collected on the environment physically, chemically and biologically. Because there are so many variables only comparable data is selected. For example, ozone depletion, human toxicity and landscape erosion may be selected and compared. The fourth and final step, interpretation and findings, is where conclusions are drawn from the life cycle inventory analysis and the impact assessment. Products may be compared with one another at this stage. There are different types of LCAs, but the two most common are process LCAs and input-output LCAs. Process LCAs are based on detailed records of emission and waste data, whereas input-output LCAs are economy based. These are available by companies, public databases and public studies. Input-output LCAs must be national, and these can be viewed per the Carnegie Mellon University’s Economic Input-Output Life Cycle Assessment model (EIO-LCA). Some key publicly available sources for information on product LCAs include the U.S. Life Cycle Inventory (U.S. LCI) Database, ATHENA Environmental Impact Estimator, SimaPro, GaBi, and EcoIndicator. LCAs are also used to score points with certification/labeling organizations such as Building Research Establishment Environmental Assessment Method (BREEAM), The United States Green Building Council's (USGBC's) Leadership in Energy and Design (LEED), the Environmental Design and Civil Engineering Environmental Quality Assessment and Award Scheme (CEEQUAL), and others. Whether one is an engineer, architect, analyst or a concerned consumer, LCAs are a valuable tool in making ecologically sound choices. Follow these links for more information: https://www.go-gba.org/life-cycle-assessment/ http://www.circularecology.com/green-building-lca-credits-in-breeam-leed-ceequal.html#.WnPMj6inGM8 http://bit.ly/2GIOnIo