By andy_5322 via flickr

There are many ways to measure the environmental footprint of a person, product or service. You may have seen calculators for determining your carbon footprint, air and water quality measures, various “green” certifications and labels, and a relatively new term in the history of environmental studies: life cycle assessments (LCA). What makes a life cycle assessment different from other measurement methods?According to the Environmental Protection Agency, an LCA is “a technique to assess the environmental aspects and potential impacts associated with a product, process, or service.” There is no one step-by-step way to perform this type assessment but the International Organization for Standardization (the ISO, which sets international standards in many subject areas) provides a section dedicated to LCA in the ISO 14000 Environmental Management Standard for purchase. The ISO standard is not prescriptive about the specific steps of an LCA, but as described in the standard abstract, it sets the general framework needed to determine the assessment goal and scope, perform a life cycle inventory analysis, impact assessment, interpretation and reporting.An abundance of LCA examples can be found online, many in the form of academic or professional journals and many by companies taking a hard look at their products and services. For example, the National Geographic Society performed an LCA on the National Geographic Magazine in 2008-2009. This entailed looking at all parts of the magazine production process from forestry and harvest, through content creation, and ultimately waste disposal and/or recycling.  They found that a year of one National Geographic Magazine printed subscription resulted in the emission of 21.84 pounds of CO2 equivalent, like burning a gallon of gas. The bulk of the emissions came from paper production and printing processes (makes you feel pretty good reading your environmental news in blog form, right?).

Beyond product and process assessments, a trend is emerging towards social life cycle assessments, which take into account the impacts of a product or service on people and society. For either assessment, the basic idea is to account for costs to the environment and/or society when considering the impact of the overall process in scope versus only accounting for the cost of materials directly consumed for the process. These measurements take a cradle to grave look at the product or service, for those products that are ultimately disposed of as waste. Or better yet, a cradle to cradle view, if the resources can be re-born in another usable form.

If you want to learn more about LCA, here are a few resources to check out:

• The EPA links to resources, case studies, and standards
• The International Journal of Life Cycle Assessment (accessible to JHU students via online library resources in SpringerLink)
• One LCA Methodology by Carnegie Mellon University