Scientists say wasting coffee and water when brewing a cup of coffee has a bigger carbon footprint than using coffee capsules. (unsplash)
Luciano Rodrigues Viana, University of Quebec at Chicoutimi (UQAC); Charles Marty, University of Quebec at Chicoutimi (UQAC); Jean-François Boucher, University of Quebec at Chicoutimi (UQAC) and Pierre-Luc Dessureault, University of Quebec at Chicoutimi (UQAC)
Global coffee consumption has been steadily increasing for almost 30 years. With an average daily consumption of 2.7 cups of coffee per person, coffee is now Canada’s most popular beverage. It is estimated that around two billion cups of coffee are drunk around the world every day.
This demand has also led to significant diversification in coffee preparation, including the manufacture of coffee capsules. The popularity of these capsules has divided public opinion, as this method of preparation with disposable individual packaging is harmful to the environment.
As researchers working on evaluating the environmental impact of products and services, we often discuss the carbon footprint of coffee.
We decided to investigate the carbon footprint of several techniques used to brew coffee at home, and it turns out that coffee capsules are not the biggest carbon contributors.
The life cycle of coffee
The exposure to home coffee making is just the tip of the iceberg.
Before you can enjoy a cup of coffee, it goes through several steps, starting with the farming of the coffee beans, transporting them, roasting and grinding the beans, to heating the water for the coffee and washing the cups into which it is poured will.
These steps, common to all types of coffee preparation, consume resources and emit greenhouse gases (GHG).
In order to be able to adequately compare the carbon footprint of different coffee preparation methods, it is important to consider their entire life cycle: from coffee production to the manufacture of packaging and machines to the coffee preparation and the resulting waste.
Comparison of four coffee preparation methods
We decided to investigate this further and conducted an extensive literature review on the subject. We then measured the carbon footprint of coffee by comparing four methods of brewing 280 milliliters of coffee, namely:
1) Traditional filter coffee (25 grams of coffee)
2) Encapsulated filter coffee (14 grams of coffee)
3) Brewed coffee (French Press) (17 grams of coffee)
4) Soluble coffee (12 grams of coffee), also called instant coffee
Our analysis has clearly shown that traditional filter coffee has the highest carbon footprint, mainly because a larger amount of coffee powder is used to make the amount of coffee. This process also uses more electricity to heat the water and keep it warm.
The carbon footprint generated over the life cycle of coffee, the preparation of different types of coffee and brewing methods. (Luciano Rodrigues Viana). author provided.
When consumers use the recommended amounts of coffee and water, instant coffee appears to be the most environmentally friendly option. This is due to the small amount of soluble coffee per cup, the lower power consumption of the kettle compared to a coffee maker and the lack of organic waste to treat.
On the other hand, when consumers use a 20 percent excess of coffee and heat twice as much water (which they often do), coffee capsules seem like the best option. Why? Because the capsules enable you to optimize the amount of coffee and water per consumption.
Compared to conventional filter coffee, drinking a capsule filter coffee (280 ml) saves between 11 and 13 grams of coffee. The production of 11 grams of Arabica coffee in Brazil emits around 59 grams of CO2e (CO2 equivalent). This value is much higher than the 27 grams of CO2e emitted by the production of coffee capsules and the disposal of the generated waste in a landfill. These numbers give an idea of the importance of avoiding overuse and wastage of coffee.
Regardless of how coffee is brewed, coffee production is the phase with the most greenhouse gas emissions. It contributed about 40 to 80 percent of the total emissions. There are many reasons for that.
The process of coffee production contributes significantly to the carbon footprint of coffee due to intensive irrigation, fertilization systems and the pesticides used. (AP Photo/Moises Castillo)
The coffee plant is a small stunted tree or shrub that was traditionally grown in the shade of the tree canopy. The modernization of the sector resulted in many coffee plantations being converted into vast fields fully exposed to the sun. This added the need for intensive irrigation, fertilization systems and the use of pesticides.
This mechanization, irrigation, and use of nitrous oxide-emitting fertilizers—which require large amounts of natural gas to produce—contribute significantly to coffee’s carbon footprint.
Reducing the carbon footprint of coffee
At the consumer level, along with reducing coffee consumption, avoiding coffee and water waste is the most effective way to reduce the carbon footprint of traditional, brewed, and instant coffees.
Coffee capsules avoid the excessive use of coffee and water. However, the convenience of capsule machines can lead consumers to double their coffee consumption, negating this environmental benefit. Consumers should also be aware of the recycling opportunities for capsules in the city they live in to avoid ending up in a landfill rather than a recycling facility. Better yet, they should switch to reusable capsules.
If you live in a province or country with high-carbon electricity generation, skipping the coffee maker hotplate and rinsing your cup with cold water can help reduce your carbon footprint.
The electricity used to wash a cup of coffee in Alberta, a high-carbon power generation province, emits more carbon (29 grams of CO2e) than making a coffee capsule and dumping it in landfill (27 grams of CO2e). In Quebec, washing your cup in the dishwasher has a negligible impact (0.7 grams of CO2e per cup) thanks to hydropower.
By the way, don’t forget to fill your dishwasher!
Limiting your contribution to climate change requires an appropriate diet, and coffee is no exception. Choosing a way of making coffee that emits fewer greenhouse gases and consuming it moderately are part of the solution.
However, more than half of coffee’s carbon footprint comes from the actions of coffee producers and suppliers. You must take action to reduce the environmental and social impact of coffee production.
Our research shows that evaluations based on a life cycle analysis or the holistic vision of products like coffee make it possible to challenge our sometimes misleading intuitive thinking. So instead of avoiding speculative products, we need to take a holistic view of our own consumption habits. Change starts at home.
Luciano Rodrigues Viana, PhD student in Environmental Sciences, Department of Basic Sciences, University of Québec at Chicoutimi (UQAC); Charles Marty, Associate Professor, University of Quebec at Chicoutimi (UQAC); Jean-François Boucher, Professor, Eco-consulting, University of Quebec at Chicoutimi (UQAC), and Pierre-Luc Dessureault, Assistant Researcher, University of Quebec at Chicoutimi (UQAC)
This article was republished by The Conversation under a Creative Commons license. Read the original article.