CarbonTracking

i was reading the EPA's National Inventory Report for Greenhouse Gas Emissions the other day. Some may say that I should get out more but these reports are real pageturners.

Anyway, rather that talk about the report, I'm just going to mention one particular chart that I saw which piqued my interest. On pg 39, we have Figure 2.4 Vehicle Numbers and Population 1990-2008.


What we have is the red bar chart showing the increase in car ownership and then the line showing the increase in population over the same period. So far, so simple.

Now at a first reading, the eye sees the level of vehicle ownership increasing at roughly the same rate as the increase in population. Good on you, Ireland, nothing to be reprimanded there.

The tricky bit though is that the population line uses a different scale, the scale on the right, the one that starts at 3 million and goes up to 4.5 million. Now you can argue that different scale is needed to make some sense of the chart, but the scale chosen is curious in that it makes the two trends, vehicles and population seem pretty much equal.

Now if we really wanted to compare trends then we should use a comparable scale, for example the % increase over a given time, i.e. if vehicle ownership goes up by 10% in the same time as population ownership goes up by 10% then we can safely say that nothing strange is going on.

So lets make a chart doing just that



Now that chart seems to tell a whole different story. Between 1990 and 2008, population increased by roughly 25% while vehicle ownership increased by a relatively whopping 140%.
So, caveat emptor, you've just got to watch out for what someone is trying to tell you in a nice chart.

Remember, the numbers never lie, once you have access to the real numbers. Its the use of the numbers that brings the spin.

Aircraft fuel,kerosene, is exempt from tax. This is kind of odd as we see the advent of carbon taxes and also when petrol/diesel for personal use is heavily taxed (€0.40/litre for diesel).

So how much of a difference would it make if the government were to tax aircraft fuel at a similar level ?

Lets take a typical mid-range airplane like B737 or an A321 uses roughly 4 litres of kerosene per 100 passenger-km. If aircraft fuel was taxed at the same rate the passenger would end up paying €16 extra for every 1000km flown.

Not too bad so far, a return trip from Dublin to Paris would cost around €24 extra. But there's a few more things to bring into play. The first is a dark subject called radiative forcing index (RFI) which is a measure of the difference, in global warming terms, of emitting CO2 at high altitudes compared to terrestrial emissions. The IPCC currently estimates an RFI of 2.7. This means that a litre of kerosene burnt at high altitudes ( above 3000m ) does 2.7 times more damage in global warming terms than a litre burnt on the ground. See here and here for more details on that topic.

So the stuff that airplanes emit is worse stuff, 2.7 times worse. Seems fair then to increase taxes accordingly, so our €24 tax increase now gets bumped up to €65. Hmm, getting saucy now isn't it.

But there's more. You see flying is about the most energy intensive activity there is known to man. Our return flight to Paris, for the weekend you know, will have used 60 litres of fuel in about 2.5 hours of actual flying or about 24 litres per hour. A Hummer ( remember those ) would use about 14 litres per hour driving around at 100 kmph. The government taxes the hell out of tHummers and the like at a tidy €2000/year of motor-tax.

So why should the same logic not apply to aircraft travel ? Why not stick on an extra 50% tax to bring it in line with other government measures to dis-incentivise. The weekender in France is now €100 more expensive but alot more equitable in environmental terms. For the sake of discussion, that shopping trip to New York would now be costing €600 more in taxes, hope those jeans were REALLY good value.

Bring on Copenhagen !

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.

Its a four step process:

• 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.