Our intern Gabriel Mestres Sanna asked himself the question: what is the environmental impact of preparing your own pizza or ordering from your favorite Italian pizzeria? He conducted a comparative LCA study to find the answers. Read all about it in the article below.
Some years ago, during the lockdown, people started trying to bake their own bread and pizzas at home. In Spain, where I am from, consumption of wheat and flour increased more than double during those days. Some people have continued on mastering the art of making pizzas (like my friend Lucas) and others have moved on with their lives and now order it from their favorite pizzeria. For this article, we took a closer look at the impact of ordering a basic pizza prosciutto or making it at home, to identify the most sustainable option.
Note; where you read kg's of CO2, we mean kg's of CO2-equivalent. This is the standardised unit to measure amounts of greenhouse gasses.
Which pizza-making method will make the difference?
For this deep dive, we compare two pizza-making methods using a life cycle assessment (LCA). First we will calculate the impact of the ingredients and their transport from Italy. For this assessment we chose to look at a pizza with prosciutto as a topping on top of a basic margarita made with mozzarella fior di latte, and the tomatoes San Marzano. If we make a pizza, we do it with the proper ingredients. That’s why we also choose a fully home-made pizza; we are not talking about a defrost pizza from your supermarket.
Once we calculate the environmental impact of the ingredients, we will assess the impact of both making the pizza at home using an oven that uses gas and making the pizza in a restaurant in a wood oven and delivery by Thuizbezorgd.
At the end, we will compare the CO2 from both pizzas, and this should give us a clear picture of their impact.
How do we approach this assessment?
To compare the environmental impacts, we will use a life cycle assessment according to the method recommended by the European Commission: The Product Environmental Footprint (PEF). To use this method, we need to clarify several variables.
- Scope: Before we begin, we have to define the scope of our assessment. The scope determines which stages of a product’s life cycle are included in our calculations. For the most complete picture, we will use a cradle-to-grave scope. This scope includes production and distribution.
- Functional unit: The functional unit serves as a performance measure for the product. It is used to communicate the impact of a product for a specific use case. In other words, it is the clear definition of what the LCA-maker is looking into: a specific product, a process, a meal, etc. For this LCA, the functional unit is a pizza prosciutto that will be eaten after being prepared.
- Impact categories: These are the aspects of the environment that are impacted by our products. The PEF has a total of 16 impact categories that go from carbon footprint to ionizing radiation and ozone depletion. Depending on the needs of the client, the LCA-maker will focus on categories more important for the case of study. To keep our assessment concise and relevant, we’ll focus on the key impact of climate change.
Where does the environmental impact originate from?
Using available data, we created two different models that included data of all the phases of the life cycle of the two pizza-making processes. The Figure below shows the results of the different processes for the different pizza’s.
Immediately, what surprises the most is that the highest impact comes from the ingredients in both cases and that the impact of the takeaway is a bit higher., We see that transport has a nearly negligible impact in both cases, and that during the baking the homemade pizza has a higher carbon footprint than the takeaway.
We modeled the pizza in the same ways regarding the ingredients used and the transport from Italy, that is why it isn’t surprising that they don’t differ that much. However, in the case of the takeaway pizza we added the impact of the box, and that is why the impact is higher.
How do the different ingredients contribute to the carbon footprint?
Overall, the impact of the ingredients is the same in both pizzas. We modeled in both cases a pizza with:
- 150g of Flour
- 90g of Tomato Sauce San Marzano
- 70g of Mozzarella Galbani
- 70g of a standard prosciutto from Albert Heijn
- Salt, water, and yeast
What is more striking from the results is the huge impact from the meat portion, which is nearly more than 80% in both cases. From all the other products, just the flour and the pizza box have a significant impact on the environment. However, it is still far from the ham.
If we look into the amount of kilograms of CO2 that one kilogram of each ingredient would emit, we can see that prosciutto is by far the ingredient with the highest carbon footprint. In comparison to the flour and the carbon pizza box, prosciutto has a relative impact almost 20 times higher. Yeast also seems to have a relatively high carbon footprint, however because a negligible amount is used in the pizza (1g), it doesn’t contribute to increasing the carbon footprint of pizzas.
How does the pizza-making method contribute to the overall carbon footprint?
Regarding the impact of the oven for each pizza, it differs substantially. In the case of the homemade pizza, we looked into the gas consumption of one of the most sold ovens to bake pizzas at high temperatures at home. Instead, for the takeaway we assumed that the oven of the pizzeria was a wood oven, just as the ones they use in Italy. In both cases we estimated that the oven would have to heat up for 30 minutes and that the pizza would take 3 minutes to bake. The Figure below shows how using a gas oven has an impact that is almost 3 times higher than the pizzeria.
Moreover, in the case of ordering takeaway we also considered the energy consumed for the delivery by e-bike. We assumed that the bike was the one used for a company like Thuisbezorgd, and that the distance would be 3 kilometers (10 minutes by e-bike). The impact of the delivery is really small, compared to the impact of the gas.
Finally, how your choices may affect the impact?
All in all, what can we take from this assessment? That we should go veggie! Kidding, do whatever you want, but take into account that the most important contributor to the carbon footprint of eating a pizza is what you choose to put on top of it.
As stated, meat has an impact that is 20 times higher than any other basic ingredient added to the pizza, even in relation to the Mozzarella cheese. Therefore, if you want to contribute to planet earth when eating, you take into account that animal products are always the most environmentally expensive.
Regarding the energy used, it seems clear that the wood oven from real pizzerias have a much smaller impact, however, it should be remarked that the impact shown in this assessment is for one single pizza. But there will hardly be any pizzeria that just bakes 1 pizza. Meaning that the carbon footprint should then be divided into the total amounts of baked pizzas, which would lower down the carbon emissions per pizza.
Ultimately, the results show that it basically depends on the toppings, so if you are trying to be more aware of your actions’ environmental impact, choosing more wisely the ingredients of your food is a good way to go!
