I didn’t always know what a first flush tea was. Although I grew up in a family of tea drinkers, I wasn’t aware of the plethora of different types of tea one can find in the local tea shop until very recently.
Living with a tea aficionado for the last year and a half has allowed me to explore the world’s finest teas and develop my palate. I still drink coffee every now and then, but tea is now a constant in my life. So, while perusing my usual sources, I was immediately drawn in by a 2007 paper that calculated the global water footprint of coffee and tea consumption in the Netherlands. Ecology, economics, AND tea? I’m in!
Water Footprint
Hoekstra and Hung (2002) were the first to introduce the concept of the “water footprint” of a nation, which is the total volume of freshwater used to produce the goods and services consumed by the nation’s population.
Therefore, in order to calculate Dutch coffee and tea related water consumption accurately, one must not only include the amount of water used in coffee machines or kettles but also the “virtual water content”, which is the volume of water needed to produce said coffee or tea. Of course, this number also takes into account the location of the water used.
How does one calculate the water footprint for coffee and tea?
This study examined many variables. For example, there are two ways of producing coffee, the wet production method and the dry production method. In the wet production method, water is needed for pulping, fermenting and washing. The total amount of water needed can vary from 1 to 15 m3 per ton of cherry, the berry that coffee trees produce, but the authors estimated that coffee producers use an average of 10m3 of water per ton of cherry. Coffee plant growth uses up most of the water in coffee production, however, so the 10m3 of water per ton cited only represents 0.34% of the total water needed to produce the coffee we drink.
Steps in the Calculation of the virtual water content of Coffee (Chapagain and Hoekstra, 2007)
The researchers assessed that the virtual water import to the Netherlands related to coffee important was 2953 million m3 a year from 1995 to 1999, where Brazilian and Columbian coffee represented 25% of this value.
From this number, however, one must subtract the total virtual water export, which results from coffee being imported into the country, roasted, and then exported elsewhere. This number adds up to about 314 million m3 of virtual water a year.
So just how much water goes into the production of a single cup of coffee in the Netherlands?
Well, the Dutch water footprint was much bigger for coffee than it was for tea because the Dutch consume a lot more coffee than tea and tea has a lower virtual water content than coffee (10.4 cubic metres per kg of tea vs. 20.4 cubic metres per kg of coffee).
If you take into account the 7 grams of roasted coffee that goes on average into making a single cup and that a standard cup of coffee is about 125 ml, you find out that a total of 140 Litres of water goes into making a single cup of coffee in a Dutch household!
Now, the Dutch drink an average 3 cups of coffee a day, which totals to 2.6 billion m3 of water being used every year to satisfy the population’s need for caffeine.
All these numbers are miniscule, however, if you consider that 110 billion m3 of water is used to make coffee every year worldwide. This number is far smaller for tea, with 30 billion m3 of water being used per year, of which the Dutch are responsible for 0.28%.
By conducting this study, Dr. A.K. Chapagain and Dr. A.Y. Hoekstra were hoping to initiate a conversation about consumer responsibility in the production of goods at distant locations because the environmental impacts are rarely taken into account in the final pricing scheme.
If you are tempted to blame the Dutch for their immoderate consumption of tea and coffee, think again. The authors of the study stress that the results obtained in the Netherland study are highly representative of the global average.
For the those of you who are concerned by these numbers but aren’t ready to give up hot beverages just yet, there is always instant coffee (80 Litres of water per cup) or, for a much more palatable option, tea (34 Litres of water per cup).
Netherlands (Chapagain and Hoekstra, 2007)
Lately, my tea of choice has been a Russian black tea. Its smoky flavour doesn’t usually suit me in the morning, but on a rainy December afternoon with a little almond milk or soy milk, it’s divine.
Chapagain, A., & Hoekstra, A. (2007). The water footprint of coffee and tea consumption in the Netherlands Ecological Economics, 64 (1), 109-118 DOI: 10.1016/j.ecolecon.2007.02.022
This work by Arielle Duhaime-Ross is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported
Great article Arielle. Perhaps you could keep going with this water footprint idea, but apply it to carnism. 2500 gallons of water go into making a pound of beef, so (my calculations here) 2335 litres go into a 4 oz. steak. Ouch! I’ll stick to rice and beans (and tea of course!).
Haha. I thought of that. I also wondered about the virtual water content of the sugar and milk that people add to their coffee or tea. If you take into account the tremendous amount of water that cows drink in order to produce milk, I’m sure the 140 Litres of water that the researchers said goes into a single cup of coffee is a huge underestimation.
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