Why & How I Show A Carbon Footprint On Recipes

You’ll notice that under all my recipes I have a description box that looks similar to the following:

This meal is around 88% less polluting than the average UK meal.

  • Eating this recipe will save around 2.59 KG CO2e per person.
  • That's equivalent to the emissions produced driving 21.37 KM in a modern car.

Why do I do this?

As I’m sure you are aware the planet currently faces climate change unparalleled in past 2,000 years. Climate change not only affects weather and ecosystems, but it affects people, especially those in the most vulnerable positions.

As it turns out, the food we consume has a big impact on greenhouse gas emissions. A 2018 study carried out by researchers at Cambridge University found 26% of the global greenhouse gas emissions are related to the food industry.

With my recipes I wanted to show how simple changes in your diet could reduce your personal carbon footprint. So I decided to just put the raw numbers on each recipe, making at easy as possible for people to see the impact for themselves.

Find out more about me and why I do this.

How do I calculate these numbers?

On each recipe I calculate each individual ingredient’s impact. This is done using a lifecycle impact assessment database I’ve built up over the years. I’ve found raw figures for this database from reading lots of scientific journals.

When I don’t have numbers for a specific ingredient I’ll make an estimation. These estimates are normally based on a similar ingredient that I do have information for. For example, I may not have information on parsnips, but have data on vegetables with a similar environmental profile, e.g. carrots and other root veggies. Then, depending on the missing ingredient I might also add additional numbers. These could be figures to account for manufacturing, transport and packaging.

When I’ve calculated individual ingredients impact I’ll combine these numbers to get a total for the whole recipe. Then I’ll divide that number by the servings for the recipe to reach get a CO2 per serving figure.

I then compare this number with the CO2 impact of the average UK meal. (This figure varies depending on study, but I use this paper which estimates 2.93 kg per meal.) I can then find how much better my recipe is than the 2.93 kg number showing it as percentage and raw figure. These are the first two numbers that appear on each recipe.

Finally I transform the raw savings figure to KM. I do this by dividing the figure by 0.121 (the average emissions per km produced by a new car in 2018.)

Want To Do This Yourself?

Do you want to benchmark your own recipes or ingredients? I’ve have built technology to allow others to tap into my database of ingredients. I can offer different solutions based on your use case. These range from simple wordpress plugins to a full API integration. Contact me to discuss.

Alternatively feel free just to shoot me a line if you’re curious about a specific ingredient/item in your weekly shop. I’ll be happy to give you a breakdown about how good/bad it might be.