Jenny Tang—CITRIS Sustainability Internship Week II
Communicating LCAs
Judgment of “good/bad” in an LCA
Communicating Life-Cycle-Analysis
The point of communicating LCAs consists of two major goals: 1. to get the audience to understand the
concept that an item’s cradle to grave (or cradle) processes and their footprints, and 2. See the key points
that cause it to become better/worse off than others in the market.
According to a presentation by LCA center by Interface Incorporated, there are a few key strategies that
are necessary to effectively communicate LCAs to a general audience1. These strategies call have the end
goal of simplifying the information via visual organization, categorization, and number presentation.
Most people get lost in the details of an LCA, as stated by the pictures. Below are some suggested
simplification processes:
Visual Organization: Visuals are crucial to understanding the predecessors and final fate of a certain
object. The visual flowchart is the quickest way to explain such a process. Usually a well-drawn flowchart
alone would accomplish the goal of getting the audience to understand “life cycle”.
Summary graphs:
Normally an excel charts of an comparative LCA between 3 products can look like this:
This is clearly beyond the scope of what the general readers would be willing grasp. Summary graphs are
useful because it will give them a qualitative message from quantitative facts. The footprint of all
processes is compiled together and then put a total net weight on each area of concern, thus directly
linking the item to the areas it impact:
Another strategy that the above graph implements is the formatting of the y-axis, where everything is
presented in terms of percent difference from baseline product A, which is set at a standard of 100%,
which unifies all different units.
Another method that can be used for comparative analysis looks like this—bubble size can also account
information that bar graphs cannot show: for uncertainty instead of only a magnitude of impact, or per
capita impact, as the case with the diagram below. Instead of percentages, this chart uses standard PVC
plastic as a baseline of “1”.
Finally, the website suggests that after presenting these simplified diagrams, a concise and clear summary
of the graphs’ main points is also needed, because how people interpret graphs are often varied. Explicit
explanations of what the graphs actually mean, and policy/action suggestions that explain what would be
the best at mitigating impact would be important ending pieces of an LCA presentation.
Value judgment of LCA
Unless the item itself generates energy or removes carbon during its usage process, every item will have a
net negative impact on the environment. Thus, assessing an item’s impacts as “good” or “bad” will be
have two factors: how an item measures to a more widely used item of a similar purpose2. Another
method of analyzing of whether an impact is looking at the specific affects that each item has. From the
above graph, if one item seems to be low impact on most categories, except for it causes eutrophication at
a rate that is 20x higher than any other product, then it can be argued that this item, due to its potency at a
specific environmental damage, would still be considered bad despite the overall net impact might not be
significant higher.
LCA analysis of PLA vs Conventional (PP) disposable cups
After searching Google web, Scholar, Jstor, Web of Science, and Academic Search Complete, I realized
that there mostly are only two articles recognized by the scientific community that involves a
comparison of PLA and conventional plastic. Some other white papers and articles were published by UC
Santa Barbara on behalf of Stonyfield Farm, a student publication that incorporated the Stonyfarm
field’s methods, an article found on International Journal of Life Cycle Assessments, a consulting
company, and one of the most comprehensive articles I’ve found was published by the Public Waste
Agency for the Flemish Region.
Unsurprisingly, these LCA’s are explained in drastically different approaches and embedded assumptions,
making comparison between each literature difficult. I will highlight the parts that I found helpful and
relevant out of an analysis I found from the private consultant, government report, and academic paper.
In Biodegradable Packaging Life-Cycle Assessment, Bohlmann of SRI Consulting analyzed the energy
footprint of different yogurt cup plastic packing. What I found unique in his paper is that he clearly
defined the functional unit, and the boundaries of each item, as well as the processes he took into
consideration when doing the Life cycle analysis. Below are some properties of his LCA:
His charts the units of MJ/kg, (Although he suggested as potentially misleading because of
performance differences between each plastic polymer, meaning different densities for items
same in size and shape)
Assumptions: Cradle to grave, no end of life treatment or plastic recycling
Biggest points of uncertainty: Lactic acid process assumptions in making PLA, end-of-life
treatment assumptions (PLA could generate methane in landfill, not much studies done)
Conclusion: PLA more energetically sustainable because of no feedstock energy (energy
consumption of raw materials usage), however, difference lessons with uncertainty principle:
A comparison of the end-of life greenhouse gas emissions in PE (LDPE or PLA plastics).
This article, for the most part, takes literatures that has been done elsewhere on raw material and
compiles them to compare PLA with LDPE
Quantity: 100,000 cups, made of cardboard but with different coating.
Inventory analysis based on previous literature
Biggest points of uncertainty: methane emission after biodegradation in landfill
Comparative LCA of 4 Types of drinking cups used at events, by OVAM (Public Waste Agency for the
Flemish Region). This has a bunch of comparative graphs that are helpful, but will present everything in
a standard 100% mark according to the standard, which then decreases many physical understanding
that one might acquire from solid units. Separation between large and small events can also give a
better idea of what is process-embedded and what is material-embedded. There are a ton of amazing
graphs that can answer pretty much every detailed question the reader might have, but what this report
has in details it lack in overall picture.
Functional unit: “Recipients needed for serving 100 liter beer or soft drink on a small scale
indoor and a large scale outdoor event”
Display unit: all graphs are in %contribution, no other units presented
Cup types: Reusable PC, PP, PE-cardboard, PLA
Most important factors for small scale: Reusable cups: Transport, disposable: production phase,
then transportation from producer to distributor
Most important factors in large scale: Transport from producer to distributor, and washing cups.
Other important factors: # trips taken to and from event
Distance from producer to distributor: 850km
Distance from distributor to event: 50km
Surprising discovery: composting does not make a significant impact, whether its 0 or 100% in
terms of life-cycle (6th graph)
Conclusions: none of the cups were significantly better than the other
Different Diagrams Displaying life cycle analysis
Source 1
Source 2:
Source 3: (Simplified)
Work’s Cited
Jenny Tang
LCA Assessment Week 3: Procedural struggles
Last week’s meeting ended with the task of doing a life cycle analysis of a simple product:
I chose a pencil. The yellow type with pink eraser, which seems to have only 10 compartments at
most: The graphite core, wood cover, polymer lining, metal binding the eraser to the wood, and
the polymer that erasers are made of.
However, I realized that if I were to use a LCA assessment cycle like sustainable-minds, I
will need to input all the processes that are involved with making this pencil and shipping to the
store. However, the difficult part comes when I don’t know where do I even begin gathering the
information. The databases are mostly incomplete in these free software tools, so I ended up
downloading multiple software packages to test out the varieties. In addition, learning about
simple manufacturing processes are also difficult without an engineering background, and
because 1.) from the product end I’m not sure what processes are required to make the shape into
what it is, and 2.) from the analysis end I’m not sure what the words in the database mean. Both
prove to be another roadblock to the analysis.
In addition, incomplete databases are an issue: The Sustainable minds database does not
have pencil graphite as one of their substances, nor the clay binding material. After realizing that
neither sustainable brands nor NREL have the database for graphite, I looked up current research
to see if there is any life cycle analysis done for pencils…. Negative.
After pushing the procedures from sustainablebrands, I learned that the life cycle analysis
usually requires a breakdown of the exact components, (materials) and then the factory site
(transportation) and the steps taken to make the material (processes).After these three categories
have been inputted, then the amount would be entered. Same for processes: material, disposal
method (landfill) etc, and lbs doing to recycling. For transportation, shipping methods and total
distance transported would be the two input values.
Some key lessons from this preliminary process of doing life-cycle analysis is that this
would be a much better tool for provided by the supply end, and external estimations done by 3rd
parties without direct access would be a rough estimation at best. LCA’s are a tool for
transparency, and would only be effective if the makers are open about their supply. The current
tools to help LCA, no matter how detailed the databases are, would be relatively ineffective if the
exactly processes and source locations are not known. The most time-consuming part, for a 3rd
party doing the life cycle analysis would not be the detailed number-crunching, but the chasing
of the sources to understand the backstory behind all the processes.
Flaws with the common type of life cycle analysis is that it does not take into account
opportunity costs: For example, when accounting for wood would it just be for the energy
required or as well with the carbon that would not be absorbed by the tree if it was not cut down?
The second flaw I see is that with the transportation method: In sustainableminds the two
transportation methods, including oceanic freighter and a truck shipment, only takes into account
the miles travels but does not take into account the weight of the object. Efficiency of the product,
and how many goods are in a shipping container total should also be taken into account, although
that would be highly varied depending on the method and I wonder if it would made a difference.
Final Result: Mechanical vs Wooden Pencil
Estimations, estimations, Boundaries.
This week has been a game of estimations and boundary settings. After emailing Ticonderoga and then
stalking Staples for a bit, I decided that I would not be getting any information from them about their
products. So, after doing a bit of research on how the general pencils are made, and what are the
common materials for each substance, I decided to estimate the most probable circumstances
Common Assumptions:
- Both pencils are 5g
- The distance between raw materials and
the factory is 200 km, via truck
- Both use the same amount of when the
pencils are gone
Wooden Pencil x 12
Plastic Pencil x 5
Wood: cedar (3g)
Process: debark and cut
Finish: varnish
Lead: graphite and clay,
Process: extrusion (1g)
Connector: stainless steel (.5g)
Eraser: rubber and clay mix (.3g)
Plastic: Polystyrene (4g)
Transportation: Made in Latin America/USA, via
Transportation: Made in China, travel via oceanic
Spring: Metal (stainless steel) (.5g)
Eraser: Rubber and Clay mix (.5g)
With these assumptions, the mechanical pencil is slightly better (43%) in usage due to the fact that it did
not use a train. Transportation was one of the largest problems that prevented the wood pencil from
being more eco-friendly. However, the manufacturing process with the mechanical process poses a
danger to the heavy plastic usage and treatment. While both have metals, the assumptions that I made
about the wooden pencil metal (stainless steel, cold press process) would be a large contributing factor
of this LCA.
Changing 2-3 processes could instantly change from mechanical pencil being about 40% better to about
700% worse off. Therefore, there is still a large amount of uncertainty to this. In addition, the locations
and shipping methods of each supply chain is unclear and would also make a big difference. In addition,
the 12 wooden pencils to 5 mechanical pencil life span is also something I assumed, but if people losing
pencils would be the limiting factor of pencil life-span, then mechanical pencils would not be better off.
Materials and Processes for the Mechanical Pencil
Materials and Processes for Wooden Pencil:
Bamboo is considered a flowering perennial evergreen. Within the last ten years the plant has been
seen for it potential for industrial use in furniture, clothing, and various other industrial and personal items.
One of the most commonly used bamboo species is called Moso bamboo, which is the largest temperature
zoned bamboo species. Initially, it seems like using this plant instead of wood or plastic has huge
benefits for the environment due to the fact that it:
Uses no pesticides and has intrinsic antimicrobial properties
Use less water
Can be harvested every 5-10 years due to rapid growth (centimeters a day for some)
Can sequester 4x as much CO2 as trees and has 35% higher oxygen output
Initial problems—large scale:
Unsurprisingly, the UN warns that half of the 1,200 species of bamboo are in danger of being
extinct or eradicated due to overharvesting as well as ecosystem destruction. The Bamboo boom into the
spotlight has driven prices higher and has stressed the bamboo growth: even though the flowers
themselves are quite resilient, if more than 30% of a bamboo plot has been harvested the plants root
system would be affected, thus changing the resiliency and growth rate of the plants. In addition, if the
plants become destroyed to the point where they need to be re-seedd, it would take about 60-100 years
before the plant flowers again into useful bamboo shoots.
LCA’s of bamboo product impacts
Not much research has been done on small scale bamboo products. There are, however, many
LCA analysis have been done by two people: Foost Foghlander, and and Pablo Van Der Lught, both of
whom have extensive on the life cycles of bamboo. For bamboo, some of the most important factors
affecdting the LCA impact are: Treatment type/processes, Yield, and Transportation. He has done
some LCAs comparing bamboo vs wood in furniture and flooring, under these assumptions:
Wood: 40% from wood plantations, 60% from rainforest, with 50% ecosystem damage
Bamboo: grown in Zhejian China, Processing Huangzhow, Zhejian, Shipped to Shanghai
and Roterdam to a Netherland Warehouse
Moso Bamboo
Heating processes use bamboo waste and sawdust as fuel
Assuming chinese transport and western transport are the same
Electricity costs for refining and processes are higher than USA.
Below are some results comparing the wood types to CLA, in terms of Eco-costs after standardizing all
environmental impacts on a monetary value:
While bamboo initially can be a great asset to replace traditional wood or plastic, many environmental
impacts are not due to the an article’s intrinsic impact. The processes that drive and occur behind the
scenes are often the most impactful. Thus, bamboo can have great benefits when replacing plastic,
however, if the processes behind shiping, processing, and growing the bamboo are intense, then the
intrinsic benefits can be offset.