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.