Here’s how your cup of coffee contributes to climate change

The Conversation

The Conversation

Nathan Dumlao via Unsplash

Global coffee consumption has been increasing steadily for almost 30 years. It is estimated that around 2 billion cups of coffee are consumed daily worldwide. But how does your cup of coffee impact climate change?

This demand has led to considerable diversification in the ways of preparing coffee as well, including the creation of coffee capsules. The popularity of these capsules has divided public opinion because this method of preparation, which uses single-use individual packaging, is harmful to the environment.

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As researchers working on assessing the environmental impacts of products and services, we often discuss coffee’s carbon footprint.

We decided to study the carbon footprint of several techniques used to prepare coffee at home, and it turns out that coffee capsules aren’t the biggest carbon culprits.

The life cycle of coffee

The pollution resulting from the preparation of coffee at home is just the tip of the iceberg.

Before you can enjoy a cup of coffee, it goes through several steps, starting from the agricultural production of the coffee beans, their transport, the roasting and grinding of the beans, right up to the heating of the water for the coffee and the washing of the cups it is poured in.

These steps, common to all modes of coffee preparation, consume resources and emit greenhouse gases (GHG).

To adequately compare the carbon footprint of several coffee preparation methods, it is important to consider their entire life cycle: from the production of coffee, through the manufacture of packaging and machinery, to the preparation of coffee and the waste produced.

Comparing four coffee preparation methods

We decided to study this further and conducted an extensive literature review on the subject. We then measured the carbon footprint of coffee by comparing four methods of preparing 280 millilitres 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 known as instant coffee.

Our analysis clearly showed that traditional filter coffee has the highest carbon footprint, mainly because a greater quantity of coffee powder is used to produce the amount of coffee. This process also consumes more electricity to heat the water and keep it warm.

A bar chart showing carbon footprint across the life cycle of coffee preparation of different coffee forms and brewing methods
The carbon footprint generated across the life cycle of coffee, preparation of different coffee forms and brewing methods. (Luciano Rodrigues Viana). Author provided.

When consumers use the recommended amounts of coffee and water, soluble coffee appears to be the most environmentally friendly option. This is due to the low amount of soluble coffee used per cup, the kettle’s lower electricity consumption compared to a coffee maker and the absence of organic waste to be treated.

On the other hand, when consumers use a 20 per cent surplus of coffee and heat twice the water needed (which is often the case), coffee capsules seem to be the best option. Why? Because the capsules allow you to optimise the amount of coffee and water per consumption.

Compared to traditional filter coffee, drinking a capsule filter coffee (280 ml) saves between 11 and 13 grams of coffee. Producing 11 grams of Arabica coffee in Brazil emits about 59 grams of CO2e (CO2 equivalent). This value is much higher than the 27 grams of CO2e emitted from the manufacturing of coffee capsules and sending the generated waste to a landfill. These figures give an idea of the importance of avoiding overusing and wasting coffee.

Coffee production

Regardless of the type of coffee preparation, coffee production is the most GHG-emitting phase. It contributed to around 40 per cent to 80 per cent of the total emission. There are many reasons for this.

The coffee plant is a small stunted tree or shrub that was traditionally grown in the shade of the forest canopy. The modernisation of the sector led to the transformation of many coffee plantations into vast fields that were fully exposed to the sun. This added the need for intensive irrigation, fertilisation systems and the use of pesticides.

This mechanisation, irrigation and use of nitrous oxide-emitting fertilisers – the production of which requires large quantities of natural gas — greatly contribute to coffee’s carbon footprint.

Reducing coffee’s carbon footprint

At the consumer level, beyond reducing coffee consumption, avoiding wasting coffee and water is the most effective way to reduce the carbon footprint of traditional, brewed and soluble coffees.

Coffee capsules avoid the overuse of coffee and water. However, the convenience of capsule machines can lead consumers to double their coffee consumption, thus making this environmental advantage redundant. Consumers should also be aware of the capsule recycling options in the city where they live to avoid it getting sent to a landfill instead of a recycling facility. Better yet, they should switch to reusable capsules.

If you live in a province or country with carbon-intensive electricity production, not using the coffee maker’s hot plate and rinsing the cup with cold water can help reduce your carbon footprint.

Shared responsibilities

Limiting your contribution to climate change requires an adapted diet, and coffee is no exception. Choosing a mode of coffee preparation that emits fewer GHGs and moderating your consumption are part of the solution.

However, more than half of the carbon footprint of coffee comes from the steps taken by coffee producers and suppliers. They must take action to reduce the environmental and social impacts of coffee production.

Our research into coffee and climate change reveals that assessments based on a life cycle analysis, or the holistic vision, of products like coffee make it possible to challenge our intuitive reasoning, which is sometimes misleading. So instead of avoiding products based on speculation, we need to take a holistic look at our own consumption habits. Change begins at home.

About the authors: Luciano Rodrigues Viana is doctorant en sciences de l’environnement, Département des sciences fondamentales; Charles Marty is adjunct professor, Jean-François Boucher is professeur, eco-consulting, and Pierre-Luc Dessureault is an assistant researcher. All are from the Université du Québec à Chicoutimi (UQAC).

This article and coffee and climate change is republished from The Conversation under a Creative Commons license.

The Conversation

The Conversation

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