I saw the BBC reality check misreport emissions from Johnson's G7 fight to Cornwall as 97 kgCO
2 (
https://www.bbc.co.uk/news/57429106). It was also brought up in the politics thread (
https://www.redandwhitekop.com/forum/index.php?topic=344128.msg17796534#msg17796534) so I did some sums on the emissions for different modes of transport. If anyone is interested here is what I came up with.
You need to make a number of assumptions, which may or may not be right, but this should give a ballpark figure, or at least an order of magnitude (OoM) understanding of the differences. OoM calculations are still useful becauase in general our carbon intuition is not very well developed.
Anyway I assumed the following:
- Johnson has an entourage of 50
- Cars are of the luxury variety (Jags, Range Rovers etc.) but have 4 passengers each.
- Coach and rail are occupied at 50% capacity to give extra space for Johnson's crew so there is room to work and the time can still be productive
( i.e. 2 x 50 seater coaches, ~30% of a single train - average passengers per train to/from London is 345 (64% of total capacity)). - The A321 (~220 seats) was chartered, not a commercial flight, so all the emissions are attributed to the entourage.
Radiative forcing (the effect of non-CO2 greenhouse gases at altitude) is not normally included in domestic flights.
Using government emissions factors (
https://www.gov.uk/government/publications/greenhouse-gas-reporting-conversion-factors-2020), and including upstream (well-to-tank) as well as combustion emissions, I get the following emissions for transporting the whole entourage one-way, over a distance of 399 km.
- Car - 1314 kgCO2e
- Coach - 1329 kgCO2e
- Rail - 1709 kgCO2e
- Plane - 23945 kgCO2e
(CO2e or CO2 equivalent includes the warming effect of non-CO2 gases like methane and nitrogen dioxide)
Comments - The car figure decreases if 5/6 seaters or less luxurious vehicles are used for 'less important' folk.
- The coaches figure is reasonably stable as one coach could be more heavily occupied than the other and still give space for the 'important' folk.
- The train figure would fall substantially (to 1139 kgCO
2e) if the half the less important folk were in standard rather than first class type seating.
- The plane figure is what it is.
It is easy to pick at the assumptions and quibble about some of the numbers but it is clear that the plane emissions were at least an order of magnitude, and probably about 20 times greater than any of the alternatives.
It is also easy to argue that other leaders travelled further, that it is a small proportion ofthe total emissions for th G7 as a whole etc. The main point is that where perfectly reasonable alternatives are available we need to start taking them.