Which one do you think is environmentally friendlier – paper cup or polyfoam cup?
The answer – it depends.
Going back to the question, how does one define “environmentally friendly”? All of us have some
shared background but vastly different experiences and expertise. The experience we bring to the
table also brings a certain level of bias to our approach on solving complex problems. An environmentalist would have a different viewpoint from an engineer. Looking at the manufacturing
data of the two types of cups - the air emissions, such as chlorine, chlorine dioxide, sulphides are
higher for manufacturing a paper cup compared to a plastic cup. But if you consider the amount of
cooling water required, the plastic cup uses higher quantities than the paper cup.
Consider a hypothetical scenario - we want to choose an environmentally friendly option for cups at
a social event. If our priority is better air quality, we go for the plastic cups as it produces lesser air
emissions. But, we cannot extrapolate the same solution to another location. Maybe the other
location has a severe shortage of water and manufacturing the plastic cups exacerbates the
situation. This is based on the assumption that the cups are manufactured in the same area as our
Let’s equate “environmentally friendly” to the ease of recyclability. Scientific studies show recycling
a paper cup is easier than a polyfoam cup, which raises the question - how do we avoid a parochial
view on environmental safety? One approach of taking various factors into account is called Life
Cycle Analysis (LCA).
Life cycle analysis studies environmental impact considering the overall cradle to grave story of a system, that is, production, use, disposal and everything in between. Having a system wide LCA approach is important as it helps us channel our focus for maximum effect. Let us take the example of cars. From studies, it can be observed that the most amount of carbon-dioxide produced by cars is during its “use-phase”, that is, over the total car use period. Equating environmental impact to green house gas emissions, we can reduce the impact of cars by focusing on vehicular mileage. We may come up with a breakthrough in technology for car manufacturing which reduces the amount of
carbon-dioxide produced during the manufacturing phase, but the overall carbon-dioxide reduction
would still be low. Now, if we have a breakthrough in the efficiency of a car engine or come up with
design changes that reduce drag on the car without additional manufacturing processes, we could
drastically reduce the amount of fuel required to run the car over its lifetime (fuel consumption
could plummet significantly).
We spend a lot of time trying to find a solution but we do not analyze the problem thoroughly. Once
we define our problem and determine the scope of our solution, we can use Life Cycle Analysis to
strategically target product life cycle stages to best address the issue.
About the Author:
With a mechanical and energy engineering background, Praneet's research is on renewable energy project development and life cycle analysis. As an international student at Purdue, his interdisciplinary masters program in Ecological Sciences and Engineering provided him with a wonderful opportunity to interact with people from different cultures and disciplines. Praneet tends to use this interdisciplinary approach towards finding solutions in his research as well.