I have been curious to look at our personal carbon footprint, and having done so thought I would share it on the blog.
Hunting around for a good personal carbon footprint calculator I came across the super useful Carbon Independent site run by Ian & Margaret Campbell. I resonated in particular with the explanatory notes on each individual emission category, and am grateful to the Campbell’s for the obvious time spent collating and updating this simple resource.
I originally ran the calculator straight off the site, but came up against a few obstacles – primarily its hard to separate my individual carbon footprint from my family (we function and hence emit carbon as a unit); and its hard to separate my personal footprint from my business footprint (the lines blur when you are self employed as a croft/cottage industry). But thanks to the explanatory notes, it was easy enough to build a basic spreadsheet to tackle these nuances. Here’s the result for our 2018 carbon footprint calculation:-
Exploring each category in turn:-
We used 6660 kWh (6.6MWh) of electricity in 2018, emitting 2.63 tonnes CO2e. I would estimate the breakdown of that is approximately 4MWh domestic usage, 1MWh doughies usage, 1MWh crofting usage and some loose electrons.
The electricity we purchase is green electricity from Octopus Energy, who have been a joyful supplier to deal with. I swapped to them last year as they only offer 100% renewable electricity, and they are one of the first suppliers to start to offer flexible tariffs linked to time of day. (If you fancy joining them, try this link as you and I share £50 off for switching).
The 2.63 tonnes of CO2e is based on a reduced 345gCO2e/kWh rate (a 25% reduction) reflecting the fact that albeit we purchase green electric, at times our supply will not be green (though in the north west of Scotland, grid carbon intensity is typically quite low with all the renewables, in particular hydro power schemes).
We used 6894 kWhth of thermal heat in 2018, emitting 2.38 tonnes of CO2e directly out the flue; that’s for hot water at the tap, and heating in the form of underfloor heating.
The heat source was a solid wood boiler district heating scheme, which services two domestic properties on the croft. I used a direct emissions figure of 345 kg/CO2e per MWhth from some Forestry Commission literature, but this assumes no subsequent tree planting whereas in reality the timber came from a locally FCS managed woodland – the same document referred to a closer to carbon neutral figure of 5kg/CO2e per MWhth for solid wood fuel as part of a bigger system, reflecting the carbon sequestering cycle inherent in sustainable managed forestry, as shown below.
We drove 12,300 km (7,638 miles) in 2018, emitting 2.71 tonnes CO2e along the way. This is based on a 220.69gCO2e/km figure of an large LPG/petrol fuelled car. I would estimate the breakdown of the mileage to be approx 2500 miles of big journeys (family adventures to the south or to the islands), 5000 miles of small regular journeys from croft to Fort William and some loose tarmac.
We did one family sleeper train journey to the south in 2018, travelling 1096 miles (used this train journey mile calculator) emitting 0.11 tonnes CO2e on the tracks. This is based on a 100gCO2e/mile figure of an average overland train trip in the UK. In reality the Caledonian Sleeper is powered by diesel locomotive for some (or perhaps all) of this journey, so this figure should perhaps be higher.
I came out with a figure of 1.17tonnes CO2e emitted from the food we eat, playing with the variables used on carbon independant. The site suggest the average emission from food is taken to be 2.2 tonnes CO2 equivalent per person. I confess my figure is purely an educated guess based on the below table:-
Food though is an area we are deeply connected to; and much of what we do on the croft is revolving around thinking about where food originates, how it is produced, and I am sure we will have a lower carbon food intensity than the mainstream, its just hard to quantify. I do think though that low carbon food and farming, and sharing how to do it is going to be important in the years ahead.
Health, Education etc
There was a further 4.2 tonnes (1.1 tonnes per person per year for the UK) of un-avoidable carbon emissions based on the calculator. I disagree with the word un-avoidable, but it represents the current average per head sharing of our current carbon heavy cultural system.
There’s a further 1.19 CO2e emitted under miscellaneous. I put this quite low based on the calculator as the logic is miscellaneous CO2e (on luxury purchases, hobbies etc) is linked to income and lifestyle – we are both a low income family and we are aware of environmental impact when it comes to lifestyle purchases.
Our total family carbon footprint summed up to 14.59 tonnes of CO2e during 2018. To put that into context the world average per person is 4 tonnes; the UK average per person is a whopping 13.4 tonnes. Per person (our family is 4) we are 3.65 tonnes of CO2e during 2018. Carbon independent suggest 1.5 tonnes of CO2e per person might be a sustainable (i.e. earth can support) figure to aim for….
Three take homes from this exercise, focusing on the biggest CO2e contributors (which we can likely impact):-
- Car Travel is our biggest personal carbon emitter – time to get those car miles down – I’d like to aim to half the mileage per annum (a target of say 4000 miles) – step 1 is cycle more & drive less. I do love our old synchro (known fondly as Mog), but recently have been entertaining the idea of either adapting to EV like this or saying farewell in favour of a pure EV. My quandary with the later is that the ideal mid 4×4 utilitarian EV doesn’t quite exist yet, but theres change afoot in the car industry so perhaps there will be soon.
- Electricity there’s a few things to consider with electricity our second biggest personal carbon emitter:-
- Install a next generation smart meter and start to offset our usage – loading at times of low cost and low carbon intensity, and load shedding at times of high cost and high carbon intensity.
- Explore self generation further in the form of croft renewables – probably a combination of solar and a micro hydro power scheme.
- Heat there’s also a few things to consider with regard to heat, our third biggest carbon emitter:-
- Validate the source of our wood fuel and the subsequent tree planting plan, perhaps seeing if there is anything required to guarantee or safe-guard the sustainability of the wood fuel we are using.
- Consider augmenting the wood fuel source with some solar hot water (which the district heating system has provision for).