This story has been updated to include a new sub-headline and comment from the Ocean Conservancy and to make even clearer that the impacts of different brewing methods are in the context of greenhouse gas emissions.
In some cases, emissions from brewing a cup of joe in an old-school filter coffee maker can be roughly 1½ times as much as using a pod machine, according to an analysis by researchers at the University of Quebec at Chicoutimi in Canada.
The study adds to a growing body of research that shows the greenhouse gas emissions of coffee are largely associated with the production of coffee and the energy needed for brewing, not its packaging. Instead, experts say, it’s important to look at a product’s entire life span — from the time it’s made to when it’s discarded — to figure out which changes might have the biggest effect on reducing your carbon footprint. In the case of brewing coffee at home, this latest study shows that it largely boils down to not wasting water or coffee.
“As a consumer, what we’re left with is the visible waste in front of us, and that often tends to be packages and plastics,” said Shelie Miller, a professor of sustainable systems at the University of Michigan School for Environment and Sustainability, who was not involved in the new analysis. “But the impact of packaging, in general, is much, much smaller than the product itself.”
Here are four takeaways from research that can help you lower the carbon footprint of drinking coffee:
Less coffee = fewer emissions
The recent study, which looked at four common brewing techniques, found that instant coffee appears to produce the least amount of emissions when the recommended amounts of water and coffee are used. This is in part because there is typically a small amount of instant coffee used per cup and boiling water in a kettle tends to use less electricity compared with a traditional coffee maker. What’s more, the method doesn’t produce coffee grounds that have to be thrown out, according to the study’s researchers.
Traditional filter coffee, on the other hand, has the highest carbon footprint, mainly because more ground beans are used to produce the same amount of coffee, the researchers wrote. This method, the researchers noted, also tends to consume more electricity to heat the water and keep it warm.
“At the consumer level, avoiding wasting coffee and water is the most effective way to reduce the carbon footprint of coffee consumption,” said Luciano Rodrigues Viana, a doctoral student in environmental sciences at Chicoutimi and one of the researchers who conducted the analysis.
The researchers did not receive any outside funding from special interest groups or companies that would benefit from their work, Rodrigues Viana said.
How you make coffee matters
The greenhouse gas emissions impact of coffee is heavily influenced by how people prepare their drinks, Rodrigues Viana said.
For example, in the case of instant coffee, if you use 20 percent more coffee and heat twice the amount of water, which often happens, then the data suggests coffee pods might be the better choice.
Meanwhile, coffee pod machines are typically designed to use the ideal amount of coffee and water, leading to less of both being wasted. Compared with having traditional filter coffee, drinking about a cup of the beverage brewed from a pod saves between 11 and 13 grams of coffee, the data shows.
“Sometimes it’s really counterintuitive,” said Andrea Hicks, an environmental engineering expert at the University of Wisconsin at Madison. She conducted a similar analysis comparing different brewing methods and also found that pods could produce fewer emissions than the conventional drip filter method, and in some cases were better than using a French press.
“Often people assume that something reusable is always better, and sometimes it is,” Hicks said. “But often people really don’t think about the human behavior.”
For instance, the latest analysis found the benefits of pods can be lost if their convenience encourages people to drink two cups instead of one.
There are also other factors to consider: How your electricity is generated plays an important role, Rodrigues Viana added. A cup of traditional filter coffee prepared using electricity mostly generated by fossil fuels can produce about 48 grams of CO2 equivalent, the analysis found. In comparison, a cup made using primarily renewable energy can emit roughly 2 grams of CO2 equivalent.
Other research has shown that adding milk can “drastically increase” the overall carbon footprint per serving.
Don’t fixate on packaging
To be sure, producing and discarding pods can have an impact on the environment that goes far beyond greenhouse gas emissions.
“The studies talk about the life cycle as though it is guaranteed that these items end up in a landfill. But that’s the best-case scenario for single-use, non-recyclable pods,” said Jordana Lewis, a spokesperson for the Ocean Conservancy, an environmental advocacy group.
When it comes to planet-warming emissions generated by drinking coffee, studies show that producing coffee and consuming energy for brewing often make up the lion’s share.
“Regardless of the type of coffee preparation, coffee production is the most GHG-emitting phase,” Rodrigues Viana and his fellow researchers wrote. “It contributed to around 40 percent to 80 percent of the total emissions.”
Packaging accounts for a much smaller share, the data shows. Here’s the math for pods: Manufacturing them and sending the used ones to a landfill generates about 33 grams of CO2 equivalent. Producing 11 grams of Arabica coffee in Brazil — the amount that can be saved by using a pod rather than brewing filtered coffee — emits close to double that amount: about 59 grams of CO2 equivalent.
If you want to help reduce the impact of packaging and do your part to avoid contributing to the growing plastic waste problem, you should recycle used pods or switch to reusable ones.
Bottom line: Be mindful
All that said, the first thing to do might be to ask yourself if you actually want that cup of coffee and whether you’re going to drink all of it, said Miller, with the University of Michigan.
“There’s not necessarily a really easy rule of thumb to tell consumers, ‘Here’s the best environmental option,’” Miller said. Instead, she recommends focusing on reducing waste and consumption overall and trying to be as efficient as possible with the resources you have.
“It really comes down to being mindful about the products that you consume and trying not to waste our products,” she added.