Tour d´EFFORTS

Difficult answer

It took quite a time to analyse the differences in the CO2 emissions between my chosen way of travelling by trains, ships and plane and the "plane-only" alternative.
In the figure "Tour d`EFFORTS CO2-Emissions" you can see the comparison of costs, duration and CO2-emissions of the two alternatives.
It can easily be seen that the mixed alternative took longer and was costlier than the plane-only alternative. Whether the mixed alternative was more climate friendly, which was the hypothesis when planning the trip, or not is difficult to answer.

Large differences between CO2-calculators

It is remarkable what differences in the CO2 emissions occur depending on what CO2-calculator you use. Therefore we calculated three different scenarios: One which gave the lowest results, one that gave the highest results and one that gave a result in between these two extremes. The results are represented by the first three double-columns of the right graphic. A special problem we found is that most CO2-calculators up to now do not include ferries and ships for passenger transport so for these legs of the journey, which constituted a large amount of the total distance, it was especially difficult to calculate the CO2 emissions.
Those CO2 calculators including ferries we found were CarboNZero from New Sealand, TravelMatters from the USA and LeedsTidal from Leeds in UK did not explain in a transparent way how they calculated the ferries´CO2-emissions. Consequently we made up our own calculation of the CO2-emissions. For the non-ferry legs we used Greenmiles from Germany because they explain in an exemplary way how the emissions are calculated. This calculation is shown in the very right double column of the right graphic.


The CO2-emissions of the "Pride of Bilbao"

For the legs by ferry we calculated the CO2 emissions with the following data:

For the journey from Portsmouth to Bilbao we learned that for a single trip the ship uses on the average 130 tons of fuel. Taking the normal ratio of carbon to CO2 of 1:4 this means 520 tonnes CO2 are emitted on the average during such a trip.
Now the question is how to distribute this over the passengers and freight transported.
It would inadequate to just split it by the weight transported because even with all cabins completely booked the total weight of the 2372 passengers would only add up to 200 tonnes taking an average weight per person of 75 kg. To transport passengers cabins are needed, restaurants, bathrooms, entertainment areas, etc. which mean weight in the construction of the ship and which has to be allocated to the passengers as well.
The lorries all together would constitute a maximum weight of 2480 tonnes if all places are booked. This would mean that 92% of the CO2 emissions are caused by the lorries but this would not be fair so a different distribution method was needed.

Willingness to pay for CO2-emissions certificates

In times of dicussions of the inclusion of ships in an Emissions Trading System (ETS) it has to be discussed how the arising costs for emissions certificates could be passed on or at least allocated to certain users of transportation.
This largely depends on the "willingness to pay". As we do not yet know the willingness-to-pay for CO2 emissions of freight transporters and passengers the current willingness-to-pay for the actual transport is a good indicator.

Then the picture looks quite different:
In June 2008 the average price for the transportation of a lorry from Portsmouth to Bilbao by the P&O run ferry "Pride of Bilbao" was 890 GBP and for a single person the lowest available fare for one leg was 133 GBP (if a return ticket was booked).
With a maximum capacity of 62 lorries of 16,50 metres each this sums up to 55180 GBP revenues from the lorries and with a maximum capacity of 2372 passangers this sums up to 315 476 GBP in revenues from the passengers. All in all that are 370 656 GBP Total revenues.
Here the larger part is payed by the passengers, 85%, and only 15% by the lorries.

Taking these proportions it means that 2372 passengers are responsible for 442 tonnes CO2 for the whole trip, averaging 0.186 tonnes CO2 (186 kg) per passenger and 78 tonnes CO2 for 62 lorries, averaging 1.26 tonnes CO2 (1260 kg) per lorry.

Method to calculate CO2-emissions of ferries

So the method to calculate the CO2-emissions per passenger/lorry is as follows:

1. Total amount of tonnes of fuel used per trip multiplied by 4 = Total tonnes CO2
2. Max. no. of passengers multiplied by the price per ticket per passenger: Total revenues passengers
3. Max. no. of lorries multiplied by the transportation price per lorry: Total revenues lorries
4. Add Total revenues passengers and Total revenues lorries: Total revenues
5. Divide Total revenues passengers by Total revenues: Revenue Portion passengers
6. Divide Total revenues lorries by Total revenues: Revenue Portion lorries
7. Multiply Revenue Portion passengers with Total tonnes CO2: CO2 emission passengers
8. Multiply Revenue Portion lorries with Total tonnes CO2: CO2 emissions lorries
9. Divide CO2 emissions passengers by total number of passengers: CO2 emissions per passenger
10: Divide CO2 emissions lorries by total number of lorries: CO2 emissions per lorry

Conclusion

Of course this is a very simplistic approach hypothesising an ideal usage of the ship but the intention was to develop a feasible calculation method. The arguable aspect is whether the "willingness-to-pay-for-fare" is an appropriate indicator for the willingness-to-pay for CO2-certificates or not. For the time being I have to say I do not know of any better method but I would be pleased to hear of better ones.

The answer to the above asked questions has to remain unaswered until more accurate data and calculation instruments are available.


Outlook

To get more realistic results for the CO2-emissions several parameters would be needed:
1. the exact type of fuel used and its content of carbon
2. the (at least average) actual usage of the ship splitted to passengers, cars and lorries
3. the actual revenues from each of these categories of customer groups.

If anyone at P&O ferries can provide these data or at least CO2-emissions based on the method as described above I would be very pleased.

Labels: CO2 Emissions