Wednesday, June 30, 2010

How (environmentally) green is your tea?

Over the years of my affair with tea, I have contemplated the environmental impact of this romance. Here I am demanding a product from the other side of the globe, having it shipped via sea or air, then trucked to my mailbox or market. That's a lot of carbon-spewing transportation. Add in certain processing procedures and packaging, and suddenly tea of any type doesn't seem very green.

Nigel Melican, one of the tea techies at Teacraft, last year studied the carbon footprint of tea, as cited in an article by Jennifer Leigh Sauer (she writes a great ecological-minded tea blog called Bon Teavant). Melican's research actually quantifies the carbon output produced by a cup of several different beverages, and finds that tea isn't so bad, after all:

Sauer sums up, saying that "tea's carbon footprint (measured by the number of grams of carbon dioxide per cup) can vary greatly from over 200g CO2 per cup to -6g CO2 per cup, depending on how the tea is grown, processed, shipped, packaged, brewed, and discarded. On average, a loose tea which you drink at a tea lounge has about 20g CO2 per cup. As a reference point, the carbon footprint of a cup of beer is 374g, a can of Coca Cola is 129g and a cup of cow's milk is about 225g. As such, loose tea is a far better choice environmentally than any of these."

Want to make your tea experience extra-green? Take into account several other factors, she adds:
  • Drink loose-leaf tea instead of bag tea. Packing tea into boxes and bags, adding nylon strings, plastic wrap and printing is fairly carbon-intensive. Loose tea usually comes in less packaging.
  • Recycle your tea. Quality oolongs, especially, can be resteeped several times without significant loss of flavor. When you're done, compost it or fertilize certain plants with it. Find other post-brew uses for the leaves, such as deodorizing your fridge. One of my favorite methods: Throw the leaves in some eggs the next morning.
  • Use gas heat to fire your kettle. I've always preferred gas stoves to electric, simply because it makes for quicker, more even cooking. I'd never thought about this breakdown before: "According to Melican, 'Gas is best as there is only one conversion loss from burning the fossil fuel to produce heat energy to raise the water temperature in the kettle. With electricity, you get five separate losses: 1. turning fossil fuel into steam, 2. steam into electricity, 3. grid losses along the wires (voltage drop), 4. transformer losses as voltage is stepped up and down, and 5. in heating the water in the kettle.'" Plus, hey, the extra heat from a gas burner helps keep your kitchen warm.

This discussion was revived last week when more, similar information cropped up in some articles in the UK press, such as this one claiming: "If you drink four mugs of black tea per day, boiling only as much water as you need, that works out as just 30kg of CO2e each year – the same as a 40-mile drive in an average car. Three large lattes per day, by contrast, and you're looking at almost twenty times as much carbon, equivalent to flying half way across Europe."

The real shock for Britons was the extra bit of information that if you add milk to tea, you're increasing the carbon footprint of your cuppa by about three times. That's not only because of the processing and transportation of the dairy, but because cows belch and otherwise emit a great deal of methane into the atmosphere.

Further study and more detailed figures on tea's energy consumption are here.

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