If you’re interested in sustainability, you’ve probably heard of a life cycle assessment (LCA). But what makes LCAs the gold standard of impact assessment? And what are they exactly?
What is an LCA?
Think of an LCA as a timeline of history. Each event on this timeline has had a catalyst and a resulting impact on history - some events have a larger impact and some events have a smaller impact. There are also different kinds of impacts: economic, political, social, etc. When we put the whole timeline together we have a comprehensive understanding of history that allows us to form opinions, draw conclusions, make decisions moving forward, and sometimes learn from past mistakes.
Now let’s rework that timeline. Instead of each tick on the timeline being a historical event, these will now represent stages in a product’s lifecycle. Most LCAs use the following life cycle stages:
Raw material extraction and processing
Manufacturing and assembly
Packaging and distribution
Use and maintenance
Disposal
* The figure above shows a highly simplified diagram of our LCA timeline. At each stage, there are inputs and impacts. But instead of catalysts to the event and social or political impacts, these are measurements of material inputs and environmental impacts. Inputs can be things like ingredients, materials, energy, etc. Impacts can be emissions that are released into the air, water, or soil. Looking at all of these life cycle stages and impacts together allows us to measure impacts, have a holistic understanding of the entire life cycle of a product, and make informed decisions based on this knowledge.
How are LCAs different from other sustainability metrics and tools?
There are several types of sustainability software that help companies manage their sustainability goals. These help companies examine everything from how their materials are sourced, to their entire operational footprint. While these tools are essential for improving sustainability, they differ from LCAs in several ways:
Scope: Many sustainability software tools focus on specific issues, such as human rights or carbon emissions, and may not provide a comprehensive assessment of a product's environmental impact throughout its life cycle.
Methodology: LCAs are based on internationally recognized standards and use scientific methods and tools to evaluate a product's environmental impact. In contrast, there are tons of sustainability tools available and they all differ widely from one another.
Transparency: LCAs provide a transparent and credible way to communicate a product's environmental impact, while some sustainability software tools may not provide sufficient transparency to enable stakeholders to evaluate a product's sustainability performance accurately. It is imperative to take a close and inquisitive look at the data sources, methods used in each tool, when certain substitutions are allowed, and whether they are appropriate.
What are the steps to perform an LCA?
This is where we dive into the science of what is involved in an LCA.
An LCA typically involves four main stages:
Goal and scope definition: This involves defining the purpose of the study. In this stage, you will also define the system boundaries and the functional unit. The system boundary is how far along the lifecycle you want to assess. Some LCAs look at all impacts from raw material extraction through disposal, while others choose to look at smaller portions of the life cycle such as raw material extraction through manufacturing. The functional unit is how much of the product you want to evaluate and is reported as the amount of a product used to perform a specific function. For example, 1,000 paperback books that are 5.5 x 8.5 x 2 inches. Some LCAs are comparing multiple different products with the same function. For example, we could expand our study to look at the impacts of 1,000 paperback books, versus that same book in hardcover.
Inventory analysis: This involves compiling a detailed inventory of all inputs and outputs associated with the product or process, including energy and material flows, emissions to air, water, and land, and waste generation. This is where you would create a process flow diagram that illustrates your product’s life cycle (similar to the figure above).
Impact assessment: This involves assessing the environmental impacts associated with the inputs and outputs identified in the inventory analysis, using established impact categories such as climate change, acidification, and eutrophication.
Interpretation: This is where we interpret the results of the LCA and draw conclusions about the environmental performance of the product or process. This may include further analysis that looks at different scenarios. For example, how do impacts change if the books are larger or smaller? What if there is uncertainty around the transportation distance and we want to test the difference between 10 and 500 miles?
LCAs are typically done using software that has all of the environmental impacts of an input already uploaded to the program. For example, if we were to be evaluating a paperback book, we would use the datasets available for the different kinds of paper, ink, the adhesive used to bind the pages, and any coatings on the cover. Then, the software can calculate the results in step three.
No two LCAs are exactly the same. It is important to note that different software acquires their data from different sources, meaning that the exact same LCA done in two different software will have slightly varying results. This is why it is imperative to be as detailed as possible when discussing methodology and to avoid trying to compare LCA results across software, scopes, and functional units.
Why are LCAs so important?
The term “LCA” is floated around all the time alluding to the gold standard of product sustainability. Now that we have an understanding of what an LCA is (and what it is not), let’s discuss why they are so important. LCAs are crucial for ensuring product sustainability across the board for several reasons:
Banishing greenwashing: It is easy for anyone to claim their product is “sustainable.” They may even make their packaging earth brown and paste it on a green leaf to really sell it. But, are they really walking the walk? LCAs provide a verifiable, data-driven look at the real impacts of a product and allow consumers to cut through any greenwashing claims.
A universal standard: LCAs provide a transparent and credible way to communicate a product's environmental impact and are standardized under ISO 14040. By using a standardized methodology, LCAs enable consumers and other stakeholders to compare the environmental performance of different products and make informed decisions based on accurate information.
Identifying hotspots: LCAs help to identify the critical environmental hotspots of a product's life cycle, i.e., the stages that have the most significant environmental impact. This stops the guessing game about what to focus on and helps businesses hone in on what will have a significant impact on the product's overall environmental performance.
Assessing trade-offs: LCAs allow manufacturers to assess the trade-offs between different environmental impacts. For example, reducing greenhouse gas emissions may increase water usage or vice versa. By using LCAs, manufacturers can make informed decisions about how to optimize the sustainability of their products while balancing these trade-offs.
LCAs are a crucial tool for ensuring product sustainability and should be an essential component of any sustainability strategy. They provide wonderful insights for the company but also allow transparency for external stakeholders to cut through any greenwashing and focus on products that have verifiable impacts.
Check our recently published peer-reviewed Lifecycle Assessment here.