In my last post, I set myself the challenge of estimating the carbon footprint of the traditional British Christmas dinner, hoping this would kick start a habit of thinking more about the impact of the food I buy and eat. I also wanted to try different methods and tools for measuring carbon, knowing that for me (and many others I’m sure!), if it’s not easy, it’s probably not going to stick.
Mike Berners-Lee’s book ‘How Bad are Bananas?: The Carbon Footprint of Everything’ is not really meant to be a tool for getting into the detail — it aims to help the reader develop a carbon instinct. Nonetheless, Berners-Lee does say that by the end I should be able “to guesstimate the footprint of more or less anything [I] come across,” which is encouragement enough to put it to the test. So here goes…
The starter
A small portion of fresh Scottish salmon generates around 400–500g of CO2. Unclear what the impact of smoking it would be, but assume it’s doubled?
A couple of slices of bread are actually very low carbon, around 80g of CO2. Berners-Lee, however, reminds us, that bread is one of the biggest culprits for food waste, which can really increase its impact.
The meat
No data for turkey, so I look at chicken. A portion of chicken is worth 2.8kg of CO2. It is the most “carbon efficient” meat, but still more than five times the impact of plant-based protein sources like lentils or chickpeas.
The veg
I promise my Christmas veg choices are more sophisticated than this… but the book gives me info for boiled potatoes and boiled carrots, both of which are very low carbon, about 200g of CO2 altogether (if you boil gently — if you boil furiously that number doubles!).
The trimmings
Christmas dinner comes with all sort of trimmings, mostly of the meaty variety. Unsurprisingly these are too niche for ‘How Bad are Bananas?’, so I add a portion of pork to the guestimations — 3.8kg CO2.
The drinks
A (perhaps conservative) half bottle of wine comes in around 1.4kg of CO2. Surprisingly, there is little difference in impact between a bottle of wine imported into the UK from France and one from Australia. This is because shipping is only a small component of the carbon footprint, the majority coming from the glass bottle and retail activities.
The dessert
Berners-Lee obviously isn’t big on puddings! But does talk quite a lot about cheese. Cheese is actually very high carbon, with a footprint that’s higher than many meats, so he asks us to “think of cheese as a meat and therefore a treat.” On average, a kilo of soft cheese (e.g. brie or mozzarella) generates 10x its weight in CO2; a kilo of hard cheese (e.g. parmesan) generates over 20x its weight in CO2. For my calculations, a small plate of cheese is probably roughly around 1kg of CO2.
Christmas excess
There’s an interesting part of the book where Berners-Lee talks about ‘Christmas excess’, which captures the wasted food, unwanted presents and avoidable travel that Christmas may bring, as well as fairy lights and cards. He estimates that in a high excess scenario, you can easily generate up to a third of the carbon that you should be aiming to generate in a year. A third of your carbon footprint for the year in one day.
I assume that my Christmas excess is typically around the UK average, which represents 280kg of CO2.
What does all this mean?
Altogether, my Christmas dinner adds up to around 10kg of CO2. But is this good or bad? Berners-Lee suggests we should be striving for a ‘5-tonne lifestyle’, which means a total carbon footprint of no more than five tonnes per year. Using this measure, my Christmas dinner uses up about 0.75 days’ worth of my annual carbon budget. I must admit that this is better than I expected, although it’s probably a low guestimate, and it’s still almost a day of 5-tonne living consumed in one meal. And if I take into account my Christmas excess, I shoot up to generating 21 days’ (290kg) worth of my target carbon footprint in one day. The Evocco app, which I mentioned in my last post, suggests that we should be targeting a footprint of 65kg of CO2 per month to live within planetary boundaries: under this scenario my meal creeps up to about four and a half days’ budget and Christmas excess would generate over four months’ worth of carbon.
But what does this really mean?
As a colleague commented on my last post, counting carbon can be complex, confusing, inconsistent, and even untrustworthy, and is something that governments and corporations are still grappling with. Does this book help with that, or just add to the noise?
Overall, I think it helps. I actually think Berners-Lee is trying to tackle some of these issues by, as he says, developing our ‘carbon instinct’. He wants to give readers a general sense of what’s higher and what’s lower, so we can make decisions that are just that bit more conscious, rather than accurately calculate our impact. He also packs the book full of references for those that do want to understand where the detail comes from.
And I do feel like my carbon instinct is slightly sharpened (especially in relation to cheese…). So next, I want to road test the Evocco app.
Mike Berners-Lee’s book ‘How Bad are Bananas?: The Carbon Footprint of Everything’ is not really meant to be a tool for getting into the detail — it aims to help the reader develop a carbon instinct. Nonetheless, Berners-Lee does say that by the end I should be able “to guesstimate the footprint of more or less anything [I] come across,” which is encouragement enough to put it to the test. So here goes…
The starter
A small portion of fresh Scottish salmon generates around 400–500g of CO2. Unclear what the impact of smoking it would be, but assume it’s doubled?
A couple of slices of bread are actually very low carbon, around 80g of CO2. Berners-Lee, however, reminds us, that bread is one of the biggest culprits for food waste, which can really increase its impact.
The meat
No data for turkey, so I look at chicken. A portion of chicken is worth 2.8kg of CO2. It is the most “carbon efficient” meat, but still more than five times the impact of plant-based protein sources like lentils or chickpeas.
The veg
I promise my Christmas veg choices are more sophisticated than this… but the book gives me info for boiled potatoes and boiled carrots, both of which are very low carbon, about 200g of CO2 altogether (if you boil gently — if you boil furiously that number doubles!).
The trimmings
Christmas dinner comes with all sort of trimmings, mostly of the meaty variety. Unsurprisingly these are too niche for ‘How Bad are Bananas?’, so I add a portion of pork to the guestimations — 3.8kg CO2.
The drinks
A (perhaps conservative) half bottle of wine comes in around 1.4kg of CO2. Surprisingly, there is little difference in impact between a bottle of wine imported into the UK from France and one from Australia. This is because shipping is only a small component of the carbon footprint, the majority coming from the glass bottle and retail activities.
The dessert
Berners-Lee obviously isn’t big on puddings! But does talk quite a lot about cheese. Cheese is actually very high carbon, with a footprint that’s higher than many meats, so he asks us to “think of cheese as a meat and therefore a treat.” On average, a kilo of soft cheese (e.g. brie or mozzarella) generates 10x its weight in CO2; a kilo of hard cheese (e.g. parmesan) generates over 20x its weight in CO2. For my calculations, a small plate of cheese is probably roughly around 1kg of CO2.
Christmas excess
There’s an interesting part of the book where Berners-Lee talks about ‘Christmas excess’, which captures the wasted food, unwanted presents and avoidable travel that Christmas may bring, as well as fairy lights and cards. He estimates that in a high excess scenario, you can easily generate up to a third of the carbon that you should be aiming to generate in a year. A third of your carbon footprint for the year in one day.
I assume that my Christmas excess is typically around the UK average, which represents 280kg of CO2.
What does all this mean?
Altogether, my Christmas dinner adds up to around 10kg of CO2. But is this good or bad? Berners-Lee suggests we should be striving for a ‘5-tonne lifestyle’, which means a total carbon footprint of no more than five tonnes per year. Using this measure, my Christmas dinner uses up about 0.75 days’ worth of my annual carbon budget. I must admit that this is better than I expected, although it’s probably a low guestimate, and it’s still almost a day of 5-tonne living consumed in one meal. And if I take into account my Christmas excess, I shoot up to generating 21 days’ (290kg) worth of my target carbon footprint in one day. The Evocco app, which I mentioned in my last post, suggests that we should be targeting a footprint of 65kg of CO2 per month to live within planetary boundaries: under this scenario my meal creeps up to about four and a half days’ budget and Christmas excess would generate over four months’ worth of carbon.
But what does this really mean?
As a colleague commented on my last post, counting carbon can be complex, confusing, inconsistent, and even untrustworthy, and is something that governments and corporations are still grappling with. Does this book help with that, or just add to the noise?
Overall, I think it helps. I actually think Berners-Lee is trying to tackle some of these issues by, as he says, developing our ‘carbon instinct’. He wants to give readers a general sense of what’s higher and what’s lower, so we can make decisions that are just that bit more conscious, rather than accurately calculate our impact. He also packs the book full of references for those that do want to understand where the detail comes from.
Next, I want to road test the Evocco app on another meal to further sharpen my carbon instinct…
