Ever Wondered? - Average Carbon Footprint & Lots and Lots of Sausages

Updated: Feb 19, 2021

How many bags of charcoal briquettes would we have to burn to produce an "average carbon footprint" of 12 tonnes of carbon dioxide - approximately how many sausages would this cook?”

Other Brands Are, Of Course, Available In This Analysis of Average Carbon Footprints ....

Nowadays it’s close to impossible to avoid discussion of carbon footprint – turn on the TV, listen to a podcast or read a blog (radio and newspapers are so twentieth century) and mention of the carbon footprint of something or other is sure to be only a few seconds away.

Here at earthrhize we’re as guilty as everyone else - although our approach to carbon footprint is subsumed within our earthrhize HALO – the approach we term as Beyond Carbon.

For a hack blog writer the carbon footprint is the gift that keeps on giving.

Carbon dioxide, as used in everyday conversations, is such an elusive concept. It’s produced and disappears into the atmosphere. We run any one of the multitude of carbon calculators and learn we produce a tonne of carbon dioxide per month because of our lifestyle.

But it’s difficult to visualise what this tonne represents in concrete terms.

At earthrhize we’re great fans of the works of Randall Munroe whose books and blogs attempt to apply scientific answers to often ridiculous questions. His work "What If? Serious Scientific Answers to Absurd Hypothetical Questions" is a must read . So in the spirit of Mr. Munroe we have decided to translate a Carbon Footprint of 12 tonnes per year, 1 tonne per month into a barbecue challenge.

The question:

“How many bags of charcoal briquettes would we have to burn to produce 12 tonnes of carbon dioxide and approximately how many sausages would this cook?”

Applying the scientific method the steps we followed are:

  1. We calculate how many kgs of charcoal briquettes we would have to burn to create a tonne of carbon dioxide gently billowing across our back garden

  2. We translate this into the number of FSC-certified bags of charcoal briquettes per year, per month, per day

  3. Applying a rudimentary rule of thumb we work out how many barbecued sausages (pork, beef or even vegan) our never tiring chef would be able to cook (not over-cooked, not under-cooked but just right).

Step 1: based on the molecular weight of CO2 of 44 (composed of 1 C atom of 12 mol and 2 O atoms of 16 mol) we calculate that every tonne of CO2 requires 270kgs of FSC-certified charcoal briquettes. (For the pedantic we assume that the charcoal is 100% dry-solids carbon, our conversion efficiency is perfect etc, etc …).

We would, therefore, need to burn 3.27 tonnes of briquettes per year

Step 2: on this basis, firing up our trusty Weber Kettle BBQ (other brands continue to be available) we would need to burn, assuming Weber’s finest FSC 4kg bags of briquettes,

  • 818 bags per year

  • 68 bags per month

  • 2.24 bags per day

We would also require a big shed and understanding neighbours

Step 3: as everyone loves a barbecue one way to getting the neighbours’ goodwill is to throw a party. For the purposes of this analysis we’ve assumed that our chef is unimaginative and his culinary skills are limited to the grilling of sausages (pork, beef, chicken even vegan).

So how many sausages would our 818 bags be able to grill?

If it had been a balmy summer’s day we would have tested the next step empirically but given it’s snowing in London today we have to apply some estimates based upon the Weber cookbook. The conclusion is a surprisingly large number of sausages:

  • take the Weber Grill Diameter of 57cm,

  • translates into a Cooking Area of 2,550 cm2,

  • assuming a Cooking Area Utilisation of 40%,

  • means we have a Cooking Area Available of 1,020 cm2,

  • we assume that we need to give our sausages plenty of room each and allocate each a generous 25cm2 for grilling purposes,

  • given the high quality nature of our grilling equipment we allow 15 minutes for a perfectly cooked sausage,

  • putting this together we calculate 163 sausages per hour

  • assuming a 1kg helping (?) of briquettes lasts 1 hour

  • a 4kg bag of briquettes cooks 653 sausages

  • 818 bags would therefore cook ......

  • 534,206 Sausages

So next time you read the words “average carbon footprint” try not to see the image of half a million sausages grilling gently as the sun shines down on the largest barbecue of the summer.

Or, think about becoming an earthrhize member ... it might make those sausages taste even better...