The source is probably an older edition of [1]. The source for that is partly [2]. That splits the figures into 35.2g / passenger-km for electric, and 704.4g f

The source is probably an older edition of [1]. The source for that is partly [2]. That splits the figures into 35.2g / passenger-km for electric, and 704.4g for diesel. The per-vehicle-km figures have a 1:3 ratio, but the per passenger figures nearer 1:20, so I think the huge disparity is due to electric trains being on much more heavily used lines. With Eurostar being 6g, they must have very high usage, or maybe the older electric trains really are much less efficient than the newest ones. [1] https://dataportal.orr.gov.uk/media/1843/rail-emissions-2019-20.pdf https://dataportal.orr.gov.uk/media/1843/rail-emissions-2019... [2] https://dataportal.orr.gov.uk/statistics/infrastructure-and-emissions/rail-emissions/table-6100-estimates-of-normalised-passenger-carbon-dioxide-equivalent-co2e-emissions/ https://dataportal.orr.gov.uk/statistics/infrastructure-and-...