ENV200H1S Tutorial #4 – Water and Carbon Footprints of Food
(last updated March 10, 2025)

INTRODUCTION
Every single product we consume, buy or sell uses water and emits green house gases (GHGs) to produce.
Agriculture is a unique sector in this perspective since it contributes to climate change at the same time it
is very sensitive to it. The availability of freshwater resources is of major importance to sustain global
food security. Climate change has a negative impact on the availability of freshwater resources since it is
projected to alter rainfall patterns and increase the frequency of extreme weather events, such as droughts
and floods. The agricultural sector takes ~40% of the world’s land area. With such a vast area, ~70% of
the global fresh water is used for agricultural production every year. Agriculture is also responsible for
75% of total nitrous oxide (N2O) and 50% of anthropogenic methane (CH4) emissions in the world. It is
also important to highlight that agriculture is the basic sector of most countries in the world and is the
center of the global economy with an estimated value of billions of dollars per year. A constant growing
human population and changing diets, mostly based on high consumption of animal source foods, has
increased the global water use and GHG emissions in agriculture. Therefore, one of the greatest
challenges of the agricultural sector in the next decades is to meet global food requirements with
sustainable management of natural resources and reduction in the emissions of pollutants to the
atmosphere, water and land. It is of major importance to analyze our lifestyle choices and understand the
impact of our diets in water use and GHG emissions in the world.

Water Footprint
The water footprint is a “measure of humanity’s appropriation of fresh water in volumes of water
consumed and/or polluted” and it is used to measure the amount of water used to produce each of the
goods and services we use. Each individual has a personal water footprint which is impacted by their
lifestyle, including diet, consumer habits, sanitation and transport. You may think your average water use
is small, since you do not leave the tap running or take long showers, however, a large majority of the
water we use every day comes in the form of virtual water. Virtual water is the volume of water used
to produce consumer products. Some of the greatest culprits come from the food we eat, especially
meat products. For example, if you were to eat a hamburger, that cow comes with a water footprint. The
cow needs to drink water, water is used to clean barns to keep them sanitary for human consumption and
water is used to grow the plants that ultimately feed the cows. In fact, agriculture accounts for nearly
92% of our global water footprint. Therefore, food we choose to eat will have a huge impact on the
amount of water we are using daily. For a comprehensive list, see
https://waterfootprint.org/en/resources/interactive-tools/product-gallery/
Carbon Footprint
The carbon footprint is the total amount of GHGs that are generated by human actions. Similar to
the water footprint, every individual has a personal carbon footprint that is related to our lifestyle, such as
diet, consumer habits and transportation. You may think that your average carbon footprint is low because
you use alternative ways of transportation, such as bicycles or public transport, however, a great part of
our GHG emissions are related to the production and transportation of the items we eat on a regular basis.
In fact, food and agriculture activities account for 1/3 of anthropogenic GHG emissions globally.
These emissions are generated in all steps of food production systems, from land modifications for crop
production/livestock maintenance to the decay of food waste that ends up in landfills and open dumps.
Therefore, food we choose to eat will have a huge impact on the amount of our daily GHGs emissions.
For more details, see https://ourworldindata.org/grapher/ghg-per-kg-poore

Moving towards sustainability
As outlined by the United Nation’s Sustainability goals, achieving food security and combating climate
change are goals we are striving for worldwide. However, when we assess global carbon and water
footprints in food production, these goals are far from being met. Due to a rapidly changing climate, many
places on Earth have seen extended and more severe periods of droughts. This has major negative impacts
in the food security of many countries in the world. Thinking about our changing climate, agri-food
production, and lifestyles, we need to ask ourselves how we can contribute to a more sustainable
agriculture through our dietary choices in order to guarantee food security for future generations.

Tutorial Objectives
 To estimate the water and carbon footprint of your diet.
 To explore elements of your diet that contribute to high water resource use and GHG emissions.
 To compare your diet`s water and carbon footprint to a global consumption, while acknowledging
climate change as a threat to food production.
 To reflect on the water resource use and GHG emissions by the agriculture sector and discuss the
feasibility of more sustainable agriculture practices.

Tutorial Assignment:
Due: March 30th by 11:59 pm. Submit through assignment link on Quercus
1. Calculate the water and carbon footprint of a 2-day diet.
2. Recalculate the water and carbon footprint of a 2-day diet substituting 3 high
volume/impact food items.
3. Compare the water and carbon footprint of your 2 diets to average North American diet
footprints.
4. Discuss impacts of your substitutions if any.
5. Discuss the steps needed to make 1 of the 3 items you substituted more sustainable and
feasible for future sustainable consumption.

Detailed steps:

1. Track your diet habits during two days. You will need to take notes of the quantities of every
item you eat and how much goes to waste. If you do not know exact quantities, estimate the best
you can. See some conversions below to help you with the calculations. Whenever possible, take
notes of where the food was produced. If you do not want to disclose your eating habits, you
can make up a diet.


 Calculate the water footprint of the items you ate over those two days using the water footprint of
food guide:
https://www.watercalculator.org/water-footprint-of-food-guide/
o After selecting a food item in the list, click on “learn more”. Check if the water
footprint of the item is categorized as small, medium or large.

o If you do not find a specific food item in the list, select the closest option. For
example, select bread for bagel.

o The website lists the water footprint for a portion size of 4 oz of a food item
produced. Remember to perform appropriate calculations for accurate results. For
example, 181 L of water are used to produce 4 oz of bread. One slice of bread has
approximately 1.6 oz. Therefore, approximately 72 L of water are used to produce
one slice of bread.

o Note that you might need to perform conversions between kilograms (KG), ounces
(OZ) and pounds (LBS) for accurate calculations. 1 kilogram = 2.2 pounds = 35
ounces.

 Calculate the carbon footprint of the items you ate over those two days using the food carbon
emissions calculator:
http://www.foodemissions.com/Calculator
o Note that you will need to know where the food was produced in order to set long
distance truck transport (miles). You can use Google Maps to estimate the distance
the food had to travel between its production and your plate. If you do not know
where the food was produced, set the long-distance truck transport to 1700 miles
- average distance between the region that holds most of the crop’s farming activities
in Canada (the Prairie Provinces - Alberta, Saskatchewan and Manitoba) and
Toronto.

o In the “set quantity purchased by the consumer (pounds)”, put the amount of a food
item you have eaten in pounds (LBS).

o In the “set consumer waste percentage”, put the approximate percentage of the
selected food item you have not eaten and disposed in the garbage.

o The total carbon footprint of a food item is equal to the sum of production,
transport, and waste CO2-e emissions

o You might need to perform conversions between kilometers (KM) and miles (MI) for
accurate calculations. 1 km = 0.62 miles

Once you have completed step 1. by determining the water and carbon footprints for all your food items
over a 2-day period, put the information into a table such as the following:
Day Food Item Quantity Distance
Traveled
Waste % Water
Footprint
Carbon Footprint
(Kg of CO2e)
1 e.g. bread 6 slices =
9.6oz=
0.6lbs
1700 miles 0 – ate all 6
slices
432 L 0.14 Kg of CO2e



2 e.g. fresh apple 1 unit =
3.52oz =
0.22lbs
1700 miles 10% - did
not eat the
middle part
82.25 L 0.04 Kg of CO2e



e.g. bowl of
pasta
1 bowl =
10.58oz =
0.66lbs
1700 miles 0 – ate the
full bowl
558.09 L 0.14 Kg of CO2e



TOTAL (sum of all food items) 1,072.34 L 0.32 Kg of CO2e
DAILY AVERAGE (Total/2 days) 536.17 L 0.16 kg of CO2e

2. Select three food items that you either 1) consume frequently in high quantities and/or 2) have a
high contribution to your dietary water and/or carbon footprints. Research about substitutions for
these items that could decrease the water and/or carbon footprint of your diet. Re-calculate your
dietary water and/or carbon footprint as described above substituting the three items you selected
by more sustainable alternatives.

3. Compare the average carbon and water footprints of your previous and new diet with the
average dietary carbon and water footprint in Canada/North America.

Average dietary carbon footprint in Canada: 6.252 kg of CO2-e/person/day
Source: Veeramani, A., Dias, G. M., Kirkpatrick, S. I. (2017). Carbon footprint of dietary patterns in Ontario, Canada: A case
study based on actual food consumption. Journal of cleaner production, 162, 1398-1406.

Average dietary water footprint in North America: 2,617 L/person/day
Source: Harris, F., Moss, C., Joy, E. J., Quinn, R., Scheelbeek, P. F., Dangour, A. D., Green, R. (2020). The water footprint of
diets: a global systematic review and meta-analysis. Advances in Nutrition, 11(2), 375-386.

4. Document and discuss your dietary substitutions and how they impacted your carbon and
water footprints (max 500 words). Summarize your previous and new diet and discuss whether
the substitutions of those three items were effective in reducing your carbon and water footprints.
You should also compare the carbon and water footprints of your previous and new diet with the
average dietary carbon and water footprint in Canada/North America. In this part, think about the
following questions:
i. Was the carbon and water footprint of your original diet higher or below the Canadian/North
American average?;
ii. What were the food items in your diet that you selected to substitute? Why did you select these
three food items?;
iii. Were the substitutions for more sustainable alternatives effective in decreasing your dietary
carbon/water footprint?;
iv. How does the carbon/water footprint of your new diet compare to the Canadian/North American
average?

5. Select one out of the three food items you decided to substitute for more sustainable
alternatives. Summarize the major problems in the production process of your selected food
item that contributes to its water and/or carbon footprint; and present an analyses of what
steps need to take place towards a more sustainable production worldwide (max 500
words). One approach is to correlate the problem in the production process of the selected food
item with the production, transport and waste carbon emissions. Take a GLOBAL realistic
perspective, not a personal perspective. All ideas should be backed by external research and be as
specific as possible. In this part, think about the following questions:
i. What are the reasons for selecting this food item in specific?;
ii. What are the major problems in its production/distribution process that contribute to its water
and/or carbon footprint?;
iii. What changes in its production/distribution process could be made to decrease its water and/or
carbon footprint?
iv. Are these changes applicable in a realistic perspective?;
v. How could these changes contribute to a more sustainable production/distribution of this food
item worldwide?
vi. Was the substitute significant and likely to be adopted by others?

 Your assessment should be written in an essay format with an introduction, body and conclusion,
in full sentences with paragraphs.

Within your assignment you should:
o Use APA in-text citation method as appropriate and for formatting references used in
your reference list;
o Incorporate additional research as appropriate since there is an abundance of interest and
sources on this topic;
o Provide any calculations you use in support of your statements; and
o Attach the results of your personal water footprint to the end of your assignment.

 Must have AT LEAST 2 peer-reviewed citations


Some resources to get started (these should not be your only peer reviewed
citations):
Karwacka, M., Ciurzyńska, A., Lenart, A., Janowicz, M. (2020). Sustainable development in the agri-
food sector in terms of the carbon footprint: a review. Sustainability, 12(16), 6463.
Mekonnen, M. M., & Gerbens-Leenes, W. (2020). The water footprint of global food
production. Water, 12(10), 2696.
Mekonnen, M. M., & Hoekstra, A. Y. (2011). The green, blue and grey water footprint of crops and
derived crop products. Hydrology and Earth System Sciences, 15(5), 1577-1600.

Grading Rubric for Tutorial Assignments
Each assignment will be graded based on the following major criteria:

Mechanics:
Follows assignment instructions addressing all identified requirements including reference
requirements and word counts.

Development of Ideas:
Arguments/main points are effective, well developed and supported with substantial evidence.

Logic & Organization:
Clear and specific introduction and conclusion. Thesis statement is explicit. Arguments/main
points are effective, well developed and supported with substantial evidence. Ideas presented in
an organized and logical manner.

References:
Appropriate references and in-text citations are used appropriately to enhance arguments.




Submission of assignments:
We will be using a plagiarism detection program within the online assignment function in
Quercus for submission of the written assignments in this course. Normally, students will be
required to submit their course essays to the University’s plagiarism detection tool website for a
review of textual similarity and detection of possible plagiarism. In doing so, students will allow
their material to be included as source documents in the University’s plagiarism detection tool
reference database, where they will be used solely for the purpose of detecting plagiarism. The
terms that apply to the University’s use of the University’s plagiarism detection tool service are
described on the Centre for Teaching Support & Innovation web site (https://uoft.me/pdt-faq).

If a student does not wish to submit to the online plagiarism tool, the student MUST advise the
head TA immediately as alternate arrangements for screening the assignment must be arranged.

To avoid late penalties, assignments must be submitted to the Quercus Assignment function
before midnight on the posted due date.

When submitting your assignment on Quercus, the file should be saved in a single file, with an
extension of .doc, .docx, .rtf, or .pdf.

It is the students’ responsibility to ensure a readable version of the correct final draft of their
assignment is uploaded by the due date. Errors in draft submissions or unsuccessful uploads are
not acceptable grounds for deadline extension and late penalties will be accrued until a correct
version is uploaded.

Late penalties
The late penalty on all assignments will be 2.5% of the assignment grade per day late, including
weekends and will only be waived with the Absence Declaration Tool on ACORN.

Students may submit one absence declaration per academic term. If additional absences occur
within the term, students may need to contact their College Registrar or submit a UofT
Verification of Illness Form. More detailed information on the absence declaration guidelines
and eligibility can be found at:

https://www.artsci.utoronto.ca/current/academics/student-absences

Please note the declaration must cover the period of time you missed, e.g. the week before the
assignment/essay is due, etc.

Requests for extensions or queries about assignment should be sent no later than Friday @ 5pm
before the due date on Sunday.

Assignments will NOT be accepted one week past the due date even if accompanied by an
absence declaration form unless prior approval has been obtained from your TA, the head TA, or
the course instructor.

Academic Integrity

The following is taken from the Faculty of Arts and Science Academic Integrity website
(http://www.artsci.utoronto.ca/osai/students):

Academic integrity is fundamental to learning and scholarship at the University of Toronto.
Participating honestly, respectfully, responsibly, and fairly in this academic community ensures
that the U of T degree that you earn will be valued as a true indication of your individual
academic achievement, and will continue to receive the respect and recognition it deserves.

Familiarize yourself with the University of Toronto’s Code of Behaviour on Academic Matters
(http://www.governingcouncil.utoronto.ca/policies/behaveac.htm). It is the rule book for
academic behaviour at the U of T, and you are expected to know the rules. Potential offences
include, but are not limited to:

In papers and assignments:
 Using someone else’s ideas or words without appropriate acknowledgement.
 Copying material word-for-word from a source (including lecture and study
group notes) and not placing the words within quotation marks.
 Submitting your own work in more than one course without the permission of
the instructor.
 Making up sources or facts.
 Including references to sources that you did not use.
 Obtaining or providing unauthorized assistance on any assignment including
o working in groups on assignments that are supposed to be individual work,
o having someone rewrite or add material to your work while “editing”.
 Lending your work to a classmate who submits it as his/her own without your
permission.

On tests and exams:
 Using or possessing any unauthorized aid, including a cell phone.
 Looking at someone else’s answers
 Letting someone else look at your answers.
 Misrepresenting your identity.
 Submitting an altered test for re-grading.

Misrepresentation:
 Falsifying or altering any documentation required by the University, including
doctor’s notes.
 Falsifying institutional documents or grades.


No outside assistance, such as generative AI systems, previous copies of assignments, or having
someone other than yourself write the assignment, are permitted in the completion of your
assignments in this course.

The University of Toronto treats cases of academic misconduct very seriously. All suspected
cases of academic dishonesty will be investigated following the procedures outlined in the Code.
The consequences for academic misconduct can be severe, including a failure in the course and a
notation on your transcript. If you have any questions about what is or is not permitted in this
course, please do not hesitate to contact me. If you have questions about appropriate research and
citation methods, seek out additional information from me, or from other available campus
resources like the U of T Writing Website. If you are experiencing personal challenges that are
having an impact on your academic work, please speak to me or seek the advice of your college
registrar.
See also the handout “How Not to Plagiarize,” Margaret Proctor, 2009, available online at
http://www.writing.utoronto.ca/advice/using-sources/how-not-to-plagiarize






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