The Ultimate Carbon Calculator

If you ever read the news, well-meaning government leaflets pushed through your door, or the sides of buses, you could be forgiven for thinking carbon was slightly below Zombie Galactus in the all-planet ranking of 'shit that will fuck you up'.

While I understand that it would be pointless (bordering on malicious) to subject everyone to an explanation of atmospheric science, chemistry and thermodynamics every time we want to tell them that pollution is bad, mkay, I think there is room for a small explanation of why everything seems to be about carbon.

In a nutshell, it's not. There are tonnes of gases being pumped into the atmosphere, many of which are what is technically known in the industry as 'a bad idea'. Some of the biggest contributors are:

• methane –- yes, hur hur, farts!
• nitrous oxide1 –- laughing gas, the first anaesthetic, cream-puffing agent and darling of festival crowds;
• ozone -– the slightly spicier version of the oxygen molecule, coming as it does with three Os living it up together. Conspicuously not found at the seaside.2
• water vapour –- so innocent, so ubiquitous, yet such a good heat absorber! Mother nature is so cruel.

And, yes, carbon dioxide, a common byproduct of the chemical reactions inside carbon-based life forms (like you, with your adorable cuddly benzene rings, you!)

After water, most of the filling in this warm, almost stifling blanket is made of CO2, and so it's become the yardstick for measuring greenhouse gas emissions. You add up the contributions to stopping heat escaping from the Earth from all these different things, say what weight of carbon dioxide would do the same job et voila — a 'carbon footprint'. It might be a stupid way of measuring things, but that never stopped anyone.

Some people will also have spotted the cunning verbal ju-jitsu in the name. Carbon dioxide is a greenhouse gas, and poisonous to humans. Carbon is a multipurpose element that life on earth probably owes its existence to.3 It seems a little rude to lump the one in with the other, but I guess there's no problem with losing accuracy in the name of losing syllables?

So given that a carbon footprint isn't just made of carbon, nor carbon dioxide; nor does it have an area; and it's a nightmare to measure; but it's still important; I present here the ultimate carbon calculator.4

To put this in perspective: the UK government hopes we will all reduce our carbon emissions by 60% by 2050, resulting in a footprint of 4.34 tonnes per Briton.

The naive, fair world target given by Contraction and Convergence (divide estimated acceptable emissions by number of people emitting, so a girl in China has the same right to use dirty power as one in Italy) is 2 tonnes per person per year.

Well, you know what they say about men with big footprints... they have big environmental cock-ups.

1. Not to be confused with nitric oxide which causes erections, among other things, and was Molecule of the Year in 1992 — possibly for that reason, possibly not. ←

2. This may just be a British thing but I, and others, were always told that the smell of the sea was due to ozone. Like many other things people repeat a lot, this ain't true. The smell of the sea is actually dimethyl sulphide, a bacterial waste product. We can still try and lyricise over it though, if you want. ←

3. There is some debate about whether elements other than carbon have the necessary qualities to create reproducing strings of molecules. The assumption that only C will do was named, somewhat charmingly, Carbon Chauvinism by Carl Sagan. ←

4. Working with Carbon Dioxide Equivalency here, not Equivalent Carbon Dioxide. Yes, I know. I'm sorry. I didn't do it. Basically the one allows for the fact that some stuff sticks around longer than carbon, as well as having different heat insulation properties, whereas the other just takes the insulation into account. ←

5. Sadly for those people whose humour is firmly wedged in the toilet, this is eructation rather than flatulence (translation: the moo, not the poo, end). But you can still giggle if you want guys! ←