Carbon cost, Leeds-Keflavík

Greenhouse gas emissions (CO₂eq): 361 kilos
Sigurðar saga fóts: 35/252

For the train ride from Leeds to Edinburgh, I’ve emailed Cross Country for emissions data, so I might update the figures for this if they share better information. But the UK Office of the Rail Regulator gives an aggregate CO₂ figure per passenger kilometre of 53.4 grammes for 2007-8; the journey was 346 kilometres (215 miles), so that’s 18.5 kilos of CO₂.

I got good data for the flight though: on landing, the pilots helpfully informed me that the flight used 4,700 kilos of fuel. I reckon there were 110 passengers on board, so that’s 42.7 kilos each. Using the brilliant Finnish statistics at LIPASTO, I infer greenhouse gas emissions (expressed as a carbon dioxide equivalent) of about 3.2 grammes per gramme of fuel burned. (If anyone wants to tell me how the emissions are heavier than the fuel then please do! Presumably it’s mostly because combustion combines the carbon and hydrogen in the fuel with oxygen from the air?) This puts my emissions from Edinburgh to Keflavík at 137 kilos.

Unless, that is, we accept that for various reasons aviation has a bigger greenhouse effect than terrestrial travel. I’ve hunted around for comprehensible up-to-date material on this, and the most useful site so far is Carbon Offset Research and Education, which suggests a multiplier of ‘at least two’, and seems fairly happy with 2.7. Let’s keep it simple at 2.5: my CO₂eq emissions from Edinburgh to Keflavík were by this reckoning 342.5 kilos. That’s the figure I’ll use for the emissions count. Needless to say, if I’d been able to get the train to Iceland, it would have been a lot better! (At some point, I’ll try and post what it would have been if I’d got the boat.)