CarbonTracking

Emissions figures are becoming pretty commonplace in our climate-change sensitive world. Every car ad will tell the the amount of grams of CO2 each kilometre produced by their latest beauty, albeit in really small text tucked down the bottom. The airline industry is getting up to speed as well, Air France, Lufthansa, BA, to mention but a few, all let you calculate the emissions generated by your flight. So far,so good, the public conscience is being served.

There's someone missing though. The ferry companies serving Irish routes are all mum on the topic. Now, Ireland is an island, at least the last time I checked, and there's quite a bit of ferry traffic going on with our neighbours. Figures from Irish ferries show that 845,000 cars and 3.27 million passengers made the trip in 2007.

Now since the ferry companies won't give the emissions info we'll have to go and look for it ourselves. Happily, Irish Ferries provide quite a few facts and figures on their 2007 activities, and with a bit of picking and choosing we can start our calculations.

• From the total fuel consumption of the fleet we can calculate the associated emissions: 206,393 tonnes CO2e
• From the revenue split we can decide how much of these emissions are due to transporting cars : 82,557 tonnes CO2e
• Breaking this down we get the emissions per car-km.: 1.13 kg CO2e
• With the car-km figure we can get the emissions related to a specific route, : e.g. Dublin-Holyhead 113kg CO2e one way

The maths for the above figures can be seen in this report. All sources are referenced so if anyone can find a mistake in the figures feel free to leave a comment.

While the figures seem quite high, one has to remember that we're talking about transporting cars here, the average car weighs in at just over a tonne, and also that passenger ferries are damn big, the Ulysses ship in the Irish Ferries fleet weighs over 50,000 tonnes.

A number of ferry companies were contacted during the writing of the report in an effort to base the report on the most accurate figures available. Without exception, the replies indicated that the ferry companies think that their emissions are their business and theirs alone.

The report does not pretend to provide definitive figures for ferry transport but rather presents a methodology and a first attempt. Only the ferry companies themselves can provide fully accurate figures.

Let's hope they think the travelling public deserves that.

It's not that hard but not that straightforward either. You're hopping from sites in the US to European sites to UK sites and the mpg-figures are all strange and working out the liters/100km is a pain.

Well no more. No bells and whistles either, just straightforward conversions with emissions figures thrown in just for the sake of it.