What Is Life Cycle Assessment?
Life Cycle Assessment, or LCA, is a method for measuring the total environmental impact of a product, service, or process from beginning to end โ often described as cradle to grave. It tracks resource use, energy consumption, emissions, and waste across every stage: raw material extraction, manufacturing, transportation, use by the buyer, and final disposal or recycling. The goal is to understand the full picture rather than focusing on just one stage.
Process LCA: The Bottom-Up Approach
Process LCA builds an environmental profile by mapping the specific inputs and outputs of each production step. Analysts gather detailed data on the energy, materials, water, and emissions involved in making a particular product or delivering a service. This approach is precise and product-specific, which makes it ideal for comparing two versions of the same item or identifying the dirtiest stage of production. However, it is time-consuming and can miss indirect impacts that fall outside the defined system boundary.
EIO-LCA: The Top-Down Approach
Economic Input-Output LCA, or EIO-LCA, takes a different path. Instead of tracking physical processes, it uses national economic data to estimate the environmental impact of spending a dollar in a given industry sector. If you spend one hundred dollars on furniture, EIO-LCA calculates the average emissions generated across the entire supply chain for that sector. This method is faster and captures a broader range of indirect effects, but it works at the sector level rather than the individual product level.
Why LCA Matters
Together, these approaches give a more complete view of environmental impact than any single measurement. Process LCA offers precision; EIO-LCA offers breadth. Using both helps individuals, businesses, and researchers make better-informed decisions about what they make, buy, and use.
Note: CarbonGuru provides scientifically and economically driven analysis for all purchasers โ individuals and businesses alike โ that draws on LCA data covering the full production and distribution lifecycle of goods, services, and activities. You get rigorous carbon footprint results without needing to run an LCA yourself.