Greenhouse gas emissions (CO2eq): 1,994 kilos
Sigurðar saga fóts: 97/252
Delta Airlines’ greenwash
Something that I was briefly slightly impressed by with Delta Airlines, the airline Victoria University booked me on to travel from Reykjavík to Toronto (via New York), and from Victora back to Leeds (via Seattle and Amsterdam), is that the travel documentation states the total distance, and the carbon emissions. (I would have chosen more direct flights, by the way, if I’d booked them myself; didn’t have my eye on the ball there.)
However, Delta Airlines say ‘the total air mileage for your itinerary is 13213’ (21,264km). The distance for my itinerary is patently not 21,264km (unless Delta have really wacky routes): the distance is (give or take) 13,213 kilometres. It does not inspire confidence that I am flying with an airline that doesn’t know the difference between miles and kilometres. Well, admittedly, when we were delayed at JFK because of a storm, the pilot was, like, ‘It’s okay, we’ll fly round the storm, we just have to plot a route. Oh, ground control think we don’t have enough fuel to fly round. Pah! Of course we do. We’ll be underway in no time. Oh, you may have noticed that we’ve switched off the engines. That’s because if we leave them on we may not have enough fuel even for our original route.’ So, er, actually maybe they really don’t know how far they’ve got to fly.
Moreover, Delta presumably emphasise the carbon emissions because they are at one and the same time trying to sell carbon offsets, which seems likely to be a money-making scheme on their part. And emissions offsets are clearly rubbish because
- No-one can guarantee that any land that’s reforested at my expense is going to stay forested for a geologically significant period of time.
- Because if it was really as cheap to offset your emissions as they say, the world would not be experiencing an environmental crisis.
If Delta were really serious about reducing emissions, of course, they’d include emissions data at the point of booking to encourage you to choose the most efficient routes—ideally accounting for things like the model of aeroplane used on that route; the proportion of seats actually occupied; and the greater footprint of business class seats, which take up extra space. And if they and other airlines used company-specific data when providing this information, consumers might start to take this into account when buying tickets, and market forces might start to reward cleaner airlines. That might actually make a bit of a difference—unlike spurious offsets.
My carbon footprint
The headline figure here is 1,633kg. Read on for the nerdy musings on this if you want!
The carbon offsetting company Delta use (who apparently do, at least, know a kilometre when they see one) reckon my trip produced 542kg of CO2 emissions. They would double this to 1081kg to account for high-altitude impacts. I was fairly impressed, in my amateur way, by the methodology in the FAQs. Though it’s irritating that they work out distances as the crow flies and then apply an ‘uplift’ figure of 10% to account for inefficiencies in routes—this figure being borrowed from the the UK government agency DEFRA. Delta must know exactly what its average seat occupancy/load factors are, and what its average fuel use is for a given crow-distance—so if they’re going to team up with a carbon offsetter, why not do it properly and use real data?
Let’s check using the LIPASTO data, which explicitly tracks emissions relative to distance as the crow flies.
- Reykjavík–New York (long haul): 4,200km × 135g CO2eq per passenger km = 567kg
- New York–Toronto (using ‘Europe long-distance’ figures): 553km × 155g CO2eq per passenger km = 86kg
- Total: 653. Not a million miles away from Delta’s 542kg, but hardly identical either.
Multiplied by 2.5 for high altitude emissions: 1633kg.
Interestingly, the DEFRA data is identical for long-haul, but finds shorter flights more efficient due to their higher seat occupancy—maybe this reflects the ruthless efficiency of Ryanair and their prominence in UK aviation, as opposed to different patterns in the Finnish aviation market, where LIPASTO’s data is from? I dunno. And the DEFRA data, interestingly, do find that economy class seats have a markedly lower footprint than business class–a mildly comforting thought. Also slightly comfortingly, if I’d calculated my Edinburgh–Reykjavík flight using my method above, I’d have reckoned it at 157kg/393kg, not the 137kg/343kg I’m pretty sure it was.
Anyway, sticking with the 1,633kg figure, this brings the trip total to 1,994kg. Incidentally, I said in an earlier post that average UK CO2eq emissions per person per year were 12.5 tonnes, and that the sustainable figure was 2–3 tonnes. Consulting the second, 2010, edition of Chris Goodall’s How to Live a Low-Carbon Life courtesy of the Dutchman, I find he’s revised the target to 2. So, through travel alone from Leeds to Toronto, I have now used up my 2011 fair share of the planet’s capacity to absorb greenhouse gases. The effects of the rest of the travelling will be felt my fellow humans, present and future.
Had I gone straight from Reyjavík to Toronto (long haul): 4,191km × 135g CO2eq per passenger km = 566kg, or 1,415kg with the multiplier. The lesson here is that flying via hubs makes a big difference to your carbon footprint. And the other lesson here is that Delta are throwing in some greenwash to make a bit of cash on the side rather than really promoting greener travel through consumer choice.