Carbon footprint of food produce - A little quiz

At the NailsworthCAN stand at the Town Meeting on the 5th April we ran a quiz on the carbon footprint of different food produce. A lot of people had a go at placing the 10 items into the 5 different emissions categories, and were often surprised at the answers.

The ten items in alphabetical order were:

• Apples (local and seasonal)

• Bananas (shipped)

• Beef from UK

• Carrots (shipped from Europe)

• Cheddar cheese

• Eggs

• Strawberries flown from SA or hothoused in UK

• Local Strawberries in season

• Cherry Tomatoes on vine hot housed in UK in March

• Salad Tomatoes (local in season)

Each produce will give rise to a certain amount of carbon dioxide due to the farming methods, transport, etc., and also other greenhouse gases (notably methane from cows burping and nitrous oxide from fertiliser). These emissions are expressed as a weight in kilograms of carbon dioxide or equivalent (written CO2e) per kilogram of produce. The emissions categories we used were:

• VERY LOW less than 1 kg of CO2e

• LOW between 1 and 2 kg of CO2e

• MEDIUM between 2 and 10 kg of CO2e

• HIGH between 10 and 20 kg of CO2e

• VERY HIGH greater than 20 kg of CO2e

The visitors then had to place 2 produce in each of these categories, which was quite a challenge!

Here is a photo of one visitor having a go

There were many surprises for people when trying to place the 10 items down, with couples debating the reasons for their choices. The answers are provided below, but why not have a go yourself before you see the answers?

• Answers (click on +)

  V LOW

  Apple (local and seasonal) 32g

  Carrot (shipped from Europe) 90g

  LOW

  Bananas 670g (0.67 kg)

  Salad Tomatoes 1.3kg

  MEDIUM

  Local strawberries in season 2kg

  Eggs 5kg

  HIGH

  Cheddar cheese 11.8kg

  Strawberries flown from SA or hothoused in UK 15kg

  V HIGH

  Beef from UK 25kg

  Cherry Tomatoes on vine hot housed in UK in March 28kg

• Hints / Lesson (click on +)

  These are the key things to bear in mind:

  1. Flying goods is much, much worse than any other form of transport of produce including shipping.

  2. Consider all the inputs from food production (like fertiliser, water and energy).

  3. Any foods coming from ruminants like cows and sheep have a high carbon footprint mainly due to burped methane.

  4. Local does not always mean low carbon.

  5. Local seasonal produce often tastes infinitely better than 'forced' ones out of season, so embrace seasonality!

Reference

For the carbon footprints of produce we used the book ‘How Bad Are Bananas?: The carbon footprint of everything’ by Mike Berners-Lee (2020 edition). It is a very useful resource that you can find at Nailsworth Library to dip into, or borrow. It includes the carbon footprint of very small things and very large ones, like sports events. In our quiz we focused on food produce as something it is easy to understand and to have some control over in our daily lives.