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10 Things to Know About Life Cycle Assessments

Life cycle assessment (LCA) has come a long way in the past few years, evolving from a niche activity carried out by academics and a few forward-thinking businesses to a mainstream practice talked about publicly by Fortune 500 companies. 

But there is still some confusion about what LCA is, what it's good (and not so good) for, and where it might be headed. 

What follows here are 10 facts -- and a few opinions -- to help shed some light on this exciting young field.

1.  LCA is a tool in a growing field called Industrial Ecology

Industrial Ecology seeks to redefine the global economy from the old paradigm of open loop systems  (linear flows of materials where resources are extracted, goods are produced and used, and waste products are disposed) to closed loop models (the goal of which is to mimic nature, where the wastes from one product are the raw materials for another). 

2.  Think "cradle-to-grave," or ideally, "cradle-to-cradle"

LCA is a "cradle-to-grave" (or, ideally, cradle to cradle) accounting of the key environmental impacts of products and services.
To perform an LCA, you essentially sum up all of the material and energy inputs to the production, use, and disposal of a product; then sum up all of the outputs (air and water emissions, materials, and waste) from each phase; and interpret the results in terms of impacts on human health, ecosystems quality, and resource depletion.

3. LCA is often performed to determine the impact of consumer products 

Though there are many uses for LCA, consumer products have long been a prominent target for practitioners. There can be many reasons for this, but it seems likely that it is a response to the growing consumer demand for environmentally-responsible products. The increasing prevalence of product carbon footprints (see next bullet) is a good example of this phenomenon.

4. A product carbon footprint is a type of LCA

There are many ways that LCA can "quantify" the environmental impact of products.  One such method is the product carbon footprint, which is really an LCA that focuses on climate change impacts.  The increasing prevalence of carbon footprinting can only be good news, as so-called supply chain carbon (that is, carbon emissions that occur outside the direct control of the company selling the final product) make up a very large percentage of the emissions associated with the goods we buy and sell every day.

5. To do an LCA the right way, you need to know (and communicate) the "What" and the "Why"

Why are you performing an LCA?  Is it intended for use only inside your organization to make improvements to a product?  Or are you intending to "go public" with your findings and make an environmental claim?  And what will you be evaluating?  Is it a single, consumer facing item (like a can of soda), or is it an entire product line (such as carbonated beverages)?  Also, what year will you be evaluating (most recent is always best)?  These are the kind of questions you'll need to answer when you state the "What and the Why" of your study (technically called the Goal and Scope), the first stage of any LCA.

6. LCA is data driven

To perform an LCA, you need a lot of data.  Some of the data is relatively easy to come by -- the amount of energy used in a manufacturing plant that your company owns and operates, for example. Other types can be extremely difficult to obtain -- a common example is a material used in your product (such as plastic packaging) that is bought from an overseas supplier. Fortunately, there are databases that contain representative information for common materials.  Some of these databases are proprietary, others free, and all are of varying degrees of quality.  But there are global efforts to improve the data available to LCA practitioners, so we can look forward to stronger and more robust results as time goes on. 

7. The Life Cycle Inventory is the meat of LCA

The grunt work of LCA begins with data collection and modeling, or Life Cycle Inventory in LCA terms. This is often made easier by drawing a process map of your product's life cycle -- a box flow diagram of all the inputs and outputs across the entire supply chain. Once this is sketched out, the LCI essentially becomes a matter of acquiring and filling in data at each relevant step. So, the LCI is really a balance sheet of all the material and energy inputs and the emissions outputs over the product's life cycle. 

8. It's not enough to know how much -- we have to place the impacts in context

After the LCI is compiled, the inputs and outputs are interpreted to broadly explain their effect on key environmental categories -- the usual suspects are human health, ecosystem quality, and resource depletion. This part of the LCA is known as life cycle impact assessment (LCIA), and is used by decision makers to make choices about how to lessen the environmental effects of the evaluated product.  So, for example, while the LCI might tell us how many grams of different greenhouse gases are emitted across a product's life cycle, the LCIA would go a step further and quantify the global warming potential of all those emissions. 

9. Interpretation

Once the life cycle inventory and assessment are finished (these are usually accomplished with the help of software tools, which are proliferating at a rapid rate), it's left to the human practitioner to frame the results. Questions such as which impact categories to emphasize the most (human health is a common choice) and which processes to focus on for improvement need to be decided. Answers to these questions are often highly subjective, and depend upon many things, such as the priorities of the organization performing the LCA, the target audience, and other issues decided in the Goal and Scope phase.

10. LCA is what we make of it

LCA is a powerful tool to help us understand the impacts of the products we make and use. But like any tool, it can be used in many different ways, some of them not so helpful. If, for example, we evaluate a "bad" product and use LCA to improve its impact incrementally, we still might not realize the true aim of our work -- the production of goods and services that do not hinder the ability of current future generations to provide for themselves. In other words, only in the context of broader sustainability goals can LCA do what it was created to do -- help to enable the creation of truly green economy.

Scott Kaufman is a senior manager at the Carbon Trust and Adjunct Professor at Columbia University, where he teaches a course in Industrial Ecology and Life Cycle Assesment (LCA).

Image courtesy of Tesco.

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