My carbon footprint according to Defra
As I've been winding down my experiments with carbon calculators, I've been noticing more and more just how variable they can be. The results they spit out fluctuate wildly but as they all ask slightly different questions, that's not surprising. What surprises me are the differences between what they claim the CO2 emissions of your average Briton are, and if your trying to figure out whether you're a relatively big emitter or a teeny tiny one, that can be something of a problem.
Most of the ones I've played with use around 10 tonnes as the average annual emissions of someone living in the UK, but not the government. Defra's whizzy and visually-appealing Act on CO2 calculator gives an average of 4.48 tonnes, more than 50 per cent less than everyone else. The reason for this shortfall is revealed in their FAQ: they're only dealing with domestic emissions, so indirect emissions are completely discounted as well as other big areas like food (which has a big impact on emissions) and waste.
Sure, if the Defra average includes only the emissions we're directly responsible for through heating, travel and electrical appliances, I guess it's easier to see the impact that changes in your lifestyle make to the results (and their calculator does encourage you to register for repeat visits to see if your emissions have fallen). But to me it feels like concealment, hiding the emissions from industry, public transport and so on that we don't have control over and yet collectively we're producing. It also encourages offsetting for dealing with flights rather than taking less which is one of those dangerous distractions from the real problem.
Bah. So I turned to Resurgence's intimidating spreadsheet of a calculator. No food or waste here either, but there's the chance to dig out my old gas bills and plug in the kilowatt hours I've used over the past year. (Okay, the Defra calculator does that too, but this one is much more comprehensive.) I also had to think back to the number of journeys I took (whoops, there's that long-haul flight again) and calculate the mileage (thank you, Google Maps).
It added up my emissions to 16 tonnes, way more than any of the other calculators I've used, but then take that flight out and it's more like 6 tonnes. Stack that up against my personal result from Defra's calculator of 3.05 tonnes and there's a whopping difference, but this just reflects the complexities in trying to tot up an accurate carbon footprint.
Meanwhile, my daily inputs into mobGAS show my CO2 emissions are still around 7 kg a day - if that remains the same across the year, I'm looking at a slender 2.5 tonnes. But since I started using it, I haven't taken any car, train or plane journeys, just a few bus rides. Add those in and the totals are going to go up rapidly and as I mentioned before, I haven't been as thorough as the calculator was perhaps expecting me to be.
So that's my overall conclusion: carbon calculators are only as good as the information you put in. Some only ask basic, top-level questions to give a broad view but by ignoring large areas factors such as food or waste, they risk being misleading. On the other hand if, like mobGAS, they ask for exquisitely detailed information you're liable to produce inaccurate results by omitting vital info. Plus the political danger is that they dump an unfair onus on individuals to cut their emissions when there's a limit to what we can all do without a lead from Westminster in the form of (you've guessed it) legislation.
I don't feel my earlier prejudices against carbon calculators have been significantly altered. They're fun, a little bit gimmicky, and can help you find some ways to lessen your personal impact, but they're just scratching the surface. But if my grumblings haven't put you off and you want to delve further, Coin have done an extensive survey of online calculators for your delight and delication.
