paper or plastic? a comparison of the carbon emissions of
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University of Minnesota Morris Digital Well University of Minnesota Morris Digital Well
University of Minnesota Morris Digital Well University of Minnesota Morris Digital Well
Undergraduate Research Symposium 2017 Undergraduate Research Symposium
4-2017
Paper or Plastic? A Comparison of the Carbon Emissions of Paper or Plastic? A Comparison of the Carbon Emissions of
Grocery Bags Grocery Bags
Hannah Tuomi University of Minnesota, Morris, [email protected]
Follow this and additional works at: https://digitalcommons.morris.umn.edu/urs_2017
Part of the Environmental Indicators and Impact Assessment Commons
Recommended Citation Recommended Citation Tuomi, Hannah, "Paper or Plastic? A Comparison of the Carbon Emissions of Grocery Bags" (2017). Undergraduate Research Symposium 2017. 2. https://digitalcommons.morris.umn.edu/urs_2017/2
This Book is brought to you for free and open access by the Undergraduate Research Symposium at University of Minnesota Morris Digital Well. It has been accepted for inclusion in Undergraduate Research Symposium 2017 by an authorized administrator of University of Minnesota Morris Digital Well. For more information, please contact [email protected].
Paper or Plastic?A Comparison of the Carbon Emissions of
Grocery Bags By: Hannah Tuomi
My Project Paper or plastic? Everyday
choice
Different bag types: plastic, paper, reusable
Question: Which bag type has the least environmental impact?
Measure of impact: Carbon emissions http://www.startribune.com/plastic-bag-ban-
proposal-heads-to-minneapolis-council-could-face-criticism/318486511/
Plastic Bags High-density
polyethylene (HDPE)
In grocery stores, 1980s
100 billion used a year in the U.S.
https://www.paxonplastic.com/ldpe-the-first-polyethylene/
Paper Bags Kraft paper
Late 1800s
10 billion used a year in the U.S.
https://www.uline.com/Product/Detail/S-18692/Retail-Bags-Paper/Paper-Grocery-Bags-12-x-7-x-17-1-6-Barrel-Flat-Handle-Kraft
Reusable Bags Non-woven
polypropylene (PP)
Introduced 1990’s
573 million imported in a year
http://www.thelivingcoast.org/wp-content/uploads/2015/12/green-bag.jpg
Functional Unit Bags have different sizes and carrying capacities
Functional unit used to compare items
How many bags it took to carry items
Ex: Carrying 483 items (one month’s shopping)
Use
Manufacture
End of Life
Premanufacture (Raw Materials)
Extraction Production
Transport
Life Cycle of a Grocery Bag
Oil or trees
Polyethylene, paper, or polypropylene
Bags at store, used by customer to carry out items
Recycle, Collection at store
ReuseEx: trash bin liner
Landfill/Incineration
Materials shaped into bags
Excluded:
1. Compost
2. Recycled
content
3. Buildings and
equipment
4. Inks and dyes = system boundary
Results- Carbon Emissions and Life Stages
Plastic Paper Reusable
End of life
Avoided products from consumer reuse
Transport
Manufacture
Premanufacture
Perc
enta
ge o
f im
pact
(%)
100%
0%
50%
Study: Edwards and Fry.
Results- Number of Bags Used in a Year and the Resulting Carbon Emissions
Type of Bag Number of Bags Kilogram CO2 eq.
Plastic 75 to 986 1.74 to 18.94
Paper 75 to 780 3.41 to 66.28
Reusable 7942
258.120.708
Studies: Edwards and Fry, Lewis et al., and Muthu et al.
Results- Number of Uses Required to Have Lower Carbon Emissions than Plastic Bags
Study: Edwards and Fry.
Type of Bag Plastic Bag-Used once
Plastic Bag-Reused once
Plastic Bag-Reusedthree times
Paper Bag 3 7 9
Reusable Bag 11 26 33
Conclusions Premanufacture for all bag types is the life stage with the
most carbon emissions
Between paper and plastic used once, plastic has a lower environmental impact
Reusable bags can have the lowest impact if used multiple times (11 to 104)
Key to lowering environmental impact is to reuse bags as many times as possible
Limitations System boundaries varied
slightly among the studies
Different definitions of functional unit
Other measures of environmental impact
http://www.swedbrand-group.com/blog/swedbrand-our-products-sustainable-and-reusable-bags
Studies Edwards, Chris, and Jonna Meyhoff Fry. Life cycle
assessment of supermarket carrier bags: a review of the bags available in 2006. Bristol: Environment Agency, Horizon House, 2011.
Lewis, Helen et al. “Evaluating the sustainability impacts of packaging: the plastic carry bag dilemma.” Packaging Technology and Science. 23 (2010): 145-160.
Muthu, Subramanian et al. “Carbon footprint of shopping (grocery) bags in China, Hong Kong and India.” Atmospheric Environment. 45.2 (2011): 469-475.
Thank You!
http://agreenliving.org/tag/co2-filter/