Transportation and its Carbon Footprint¶

In Summary: Everything up to 400km is probably better travelled on the surface as much as possible excluding CO2 consuming motorised transport. Everything above 400km travelled by air travel. Air-travel has had a ‘bad-rap’ but this has forced it to clean up and become more efficient. Budget airlines are often more efficient as they ‘pack’ more people on board and often have newer or upgraded aircraft.

Climate Change Transport Air Travel

Simon Harper

02 Jan 2020

5 min read

From my previous post you’ll notice that I only touched on transport. This is because it is such a contentious topic that I felt it needed a small article all to itself. As with everything the message here is nuanced because the calculations are not primarily based on CO2 alone but also on travel time, distance, time available, location of destination, number of people traveling and whether the form of travel accommodates the multiple travelers, and if there are dependants etc.

In general I’d suggest (based on the UK National Travel Survey) that journeys less than 1km walk, run, or cycle where possible. For 1km to 3km run or cycle, bus or tram, 2km to 5km some form of electric personal transport, bus or tram, or cycle. 5km is a boundary I think because it represents a distance most people can travel without motorised aid. After this we get into motorcycle, scooter, car, bus, tram, train territory with an average UK commute of 14.4km (9 miles) each way. Unless you are very close to a tram, train, or bus route this means personal motorised vehicle upto 25 miles (pg8). Then looking at the data we skip up to 25 miles to less than 50 representing only 25 trips per person per year. Trips 50 miles and upwards are very rare it seems of the average 774 trips per year.

LIST 1: So for the average person I’d say:

self powered or electric assist up to 5km
self powered or electric assist and public transport (or some combination thereof) up to 15km
Train, metro, tram, light commuter railway (if available) and motorised transport (car etc) up to 40km (25 miles)
Train up to 300km (~200 miles - without a water crossing) but this is a calculation - Manchester to Glasgow, say, is approx 200 miles with a train travel time of 3h 30m. Flight time is 1h 05m plus an hour each end (say) and the time to get to the airport which will typically be much further for most people than their local station. So I would revise this and say everything up to 400km is probably best accomplished via train where possible.
Above 400km (with/without a water crossing) then air-travel.

Lets jump into the most contentious topic, air travel. Now given Greta Thunbergs recent Atlantic crossing by yacht you might be thinking that flying is really the wrong thing to do, aside from the construction costs (in CO2) of a yacht which has only one purpose (to race - so nothing useful). Well again, for me it depends as to the overall CO2 used by an individual. Previously I said:

‘We have become focused on a small number of single remedy solutions which uses a shorthand; for instance, flying=bad, trains=good (giving rise to the practice of ’flight-shaming’). This practice is both lazy, inaccurate, and prone to exclude a majority of people who are poor in both time and or money, while paradoxically scape-goating the sector of the population who, with their limited ability to consume, are likely to use the least CO2. As an example, the price of a return fare from Manchester to London is in the order of £120, while a flight from Manchester to Southern Spain comes in at £40 return. Telling people that they should, for instance, take the train on holiday is unfeasible, and what’s more, fundamentally misunderstands the nature of the buy-in required across society if we are to address climate change with any level of speed and success.’

It’s safe to say that air travel has had a CO2 bashing over the last few years and this has had some positive effects in terms of efficiencies in the industry. Indeed, most of the online tools seem to be using out of date metrics for calculating flight costs - and this is compounded when costs can vary significantly even down to the carrier. I’m finding it better to look at industry standards and work on an airline by airline basis.

The things to remember are the efficiency of the ‘hardware’. Planes vary - new or upgraded hardware will perform significantly better. Collated from this well sourced wikipedia page the most efficient planes in each sector put cars etc to shame.

Type	Model	Year	Seat	Fuel burn	Fuel per seat
Commute	ATR 72-500	1997	70	1.42 kg/km (5.0 lb/mi)	2.53 L/100 km (93 mpg‑US)
Regional	Airbus A321neo	2015	192	3.30 kg/km (11.7 lb/mi)	2.19 L/100 km (107.4 mpg‑US)
Short Haul	Airbus A220-300	2015	135	2.30 kg/km (8.17 lb/mi)	1.85 L/100 km (127 mpg‑US)
Med. Haul	Boeing 737 MAX-8	2017	168	2.86 kg/km (10.1 lb/mi)	2.13 L/100 km (110 mpg‑US)
Long Haul	Boeing 787-9	2013	304	5.63 kg/km (20.0 lb/mi)	2.31 L/100 km (102 mpg‑US)

Secondly, the carrier is significant. Counter to my initial beliefs the budget airlines come out better. This is because they ‘pack’ more people in the planes. We can calculate the efficiency in terms of CO2 per passenger per mile/kilometre. So this means the more people on a flight the more efficient the flight. In Europe this has had the effect of making Ryanair the most efficient carrier, with premium carriers such as British Airways being very much less efficient due to first class, business, and premium economy where the passenger density is much less.

‘MSCI ranked Ryanair as the lowest-emissions-intensity airline in its ACWI index with 75 g CO2-e/revenue passenger kilometre in 2014 – below Easyjet at 82 g, the average at 123 g and Lufthansa at 132 g – by using high-density 189-seat Boeing 737-800s. In 2015 Ryanair emitted 8.64 Bn t of CO2 for 545,034 sectors flown: 15.85 t per 776 mi (674 nmi; 1,249 km) average sector (or 5.04 t of fuel: 4.04 kg/km) representing 95 kg per 90.6 million passengers (30.4 kg of fuel: 3.04 L/100 km or 76 g CO2/km).’ Ryanair Annual Report 2015.

In real terms this means that Ryanair announced July 2019 figures of 67g of CO2 per pax /km (pax meaning ‘Persons Approximately’). Their environmental policy document might be useful when considering who to fly with but Brighter Planet’s: Air travel carbon and energy efficiency report gives a really nice breakdown from page 17.

Important

So what does all this mean for me (and maybe you)?

I’ll continue to monitor and try and reduce my CO2 usage in my day to day travels;
I’ll measure this via car-miles being cautious and assuming I am the only one in the car even if I am transporting more than myself;
I’ll try and follow my advice in LIST 1; but,
I’ll still take air travel trying to find the most efficient carrier and routes. I’ll include all personal flights, and for work (where I have the choice to attend or not) I’ll separate this out so that I can see how I might start to reduce this figure. If my employers send me on a trip that I don’t arrange then it’s on their CO2 budget.

Note

Version e973224ab3bcb50cae5e0e2d5f0468f700bf09a0 created on 22/12/2022 @ 15:34. This page is licensed under a Creative Commons Attribution 4.0 International License.