Carbon footprint calculation is a murky science. What to do, when you’ve done everything that you can, and it still might not be enough? Answer: hug a tree

Wielding the pumice stone, scrubbing my grubby carbon feet clean, I fretted over this dilemma: is it possible to live both “normally” and sustainably, when life as we know it is inherently unsustainable? Can one live a simple life in style, without retiring to Gricklegrass Farm*? If I can’t tweak my life into sustainability, bolstered by moderately fortunate circumstances and natural inclination, who in the world can?

Carbon footprint calculators are two-a-penny on the web and, like most things that are two-a-penny on the web – including, probably, blogs about sustainability – mostly worth less than the paper they’re not printed on. They all have some things in common; they ask questions about electricity consumption, transport miles and, sometimes, other lifestyle factors, feed them into an (undisclosed) algorithm, and burp out a number. They each have some differences – some explicable, others mysterious, like their varying footprint sizes.

The calculators (I chose three):

1. carboNZero, hosted by Landcare Research – thus, presumably, tailored to New Zealand circumstances, with the imprimatur of the government. It focuses on transport and electricity, with good reason. Overwhelmingly, setting aside agriculture, it’s emissions from road transport and electricity generation that comprise most of New Zealand’s carbon emissions. Similarly, it considers only the methane from rubbish; if all food waste is composted and paper recycled, you get a full rebate on rubbish emissions. However, it doesn’t ask any secondary lifestyle questions that must, albeit indirectly, affect personal carbon footprint size and climate change impact. Acknowledging the technical correctness of counting at point of emissions, this seems a bit limited.

2. The Earth Day calculator, which is affiliated with WWF, and based on the same ecological footprint concept as WWF’s Living Planet report. It's sustainability, not climate change, focused. It’s extremely cool, if you’ll pardon the pun; it plays mood music while an avatar builds his/her/your virtual life. As well as transport and electricity, the avatar ponders food (eg, local, minimally processed), water, rubbish, and consumption of stuff in general.

3. carbonfootprint.com, for no better reason than it is the highest ranked on Google and seemed to ask roughly the right questions. (Although some were, frankly, bizarre. “I don’t even have a bank account”. Really?) It gives the scariest results, which might be because it is also the front for a carbon offsetting scheme, or (more charitably) because, although it asks you to specify country, it’s not good at recognising country differences (eg, agriculture methods, renewable electricity).

The calculation:

You have to know a thing or two, like transport mode and distance per year, and power consumption in kilowatts.

Meridian Energy, whose electricity is renewable and carbon neutral, was a conundrum: count it, or not? In theory, the right answer (I think) is supposed to be “not”. But in practice, that doesn’t quite work. If we all signed up to Meridian, the company would have to buy from other generators with sootier profiles. Also, whether it’s me or my neighbour who switches on the light, we’re all drawing on the same energy mix; it all comes out of the same grid. Carbon neutrality doesn’t achieve carbon reduction and, renewable or not, electricity is resource-intensive, damming (and damning) rivers and – much as I love windmills – filling landscapes. Anyway, long story short, I counted it – as a proxy for my fire, if nothing else.

The results:

1. carboNZero - 2.8 tonnes CO2-e (carbon dioxide equivalent) counting electricity, 1.7 tonnes CO2-e with electricity omitted.

2. Earth Day - 7.7 tonnes CO2-e, and if everyone lived like me, we would need 2.4 planet earths. Even using wildly hypothetical examples (eg, house off grid, no motorised transport at all) the lowest result I could extract from this calculator was 1.5 planets and a carbon footprint of 3.5 tonnes. There were no options for “I live in a tent” and “forage for my food”. The subliminal message might be, there’re already just too many people on the planet.

3. carbonfootprint.com - 7.8 tonnes CO2-e. When I omitted the “secondary” lifestyle factors, so that the questions were identical to carboNZero’s, the result was 4.4 tonnes CO2-e compared to 2.8.

The target:

This is evidently an imprecise science. What follows is imprecise.

1. Setting a “40 by 2020” or whatever target from a personal starting point seems a bit unfair for anyone starting off a low base (or, for that matter, a high one).

2. Assuming that averages are more robust – and putting aside, for now, the small problem that the per capita average must reduce as the world population rises – New Zealand’s average per capita emissions are 17 tonnes CO2-e, 48% of which is attributable to agriculture, around 80% of which is exported, which gives a target of 2 tonnes per capita by 2050 (a reduction of 80% of the remaining 10.4 tonnes). The world average per capita is, in generously rounded figures, 5 tonnes – a 1 tonne per capita target.

3. The IPCC reduction target date is 2050. This is 2009. Whether reduction happens closer to now or 2050 affects total emissions, meaning that sooner is better. Alternatively, if we would have to live like peasants today to achieve a reduction target, it’s arguably better to hope for the benefit of technology to blunt the impact of lifestyle change. Overall, a footprint today of anywhere between 1 and 3 tonnes CO2-e (3 tonnes being the “40 by 2020” global average target) would seem to be a goodish effort.

If, at 2.8 tonnes, my carboNZero status quo is all it takes then yes, you can live a sustainable life in style, and no, it’s not that hard. For every advantage that I obliquely summed up as “moderately fortunate circumstances”, there are some countervailing handicaps (eg, some scary public transport miles).

Otherwise I’m at my wits’ end to know what else to do, having done everything and more that all the lists say to do. Certainly, everything short of the Ministerial-income electric-car type frolics that the average person can probably afford. For Al Gore’s “air conditioning thermostats” and “fully loaded dishwasher”, substitute “windows” and “hands”. I even registered for an natural burial. I will at least die, if not live, sustainably.

Some other possibilities:

1. Dismiss all of the calculators as the spawn of zealots and capitalists.

2. Take the wrecking ball to my snug little wooden cottage, and build a “little greenie”. But that seems kind of anti-sustainable, historically churlish, would break my heart, and if it’s good enough for Mr Gore (who preferred to renovate his inconvenient house) … etc.

3. Offset aspects of the footprint that are currently unavoidable. But the world’s capacity for robust offsetting schemes is going to be over-subscribed.

Sitting in my cottage in the incipient forest, watching the weather, and worrying, I realised it is actually laughably simple. There are several dozen little trees out there, flailing in the wind, planted by me, that will absorb 1 tonne CO2 each in their lifetime. Their frail shoulders seem unequal to the weight of the world, but they give me 10 years’ grace while I think about what to do next – if anything, because in 10 years’ time, we should know one way or the other whether our goose is cooked.

* “Once there were bare-breasted girls driving tractors through fields of organic barley … ”. Founded in the early 1970s in Oxford, North Canterbury by Marian Hobbs and others, the Gricklegrass Community is having a renaissance, of sorts: “Mr Bushell has already lost his first three would-be helpers. Expressing regret, they went back to the city when the countryside got too dark, too cold, too impractical … Standing in the chilly field, with a fresh hole in his ragged trousers from clambering over a wire fence, he looks suddenly disheartened. There is a staggering amount yet to do, he says. They are so unready. And the future so grimly uncertain.” (Dominion Post Weekend, A15, 25-26 July 2009)