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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).