The calculator uses a figure of 100 g CO2 / mile.
This is based on an overall figure of 49 g/km i.e. 80 g / mile (or 0.080 kg / mile) - from the AEA Report [23]. This gives a range from 19 g/km to 71 g/km for intercity trains depending on route, engine type (diesel or electric) and passenger load (ranging from 44% to 68%).
Allowance is needed for the fossil fuel used in oil exploration and refining (which is overall around 85% efficient - see car sources page), and for train and track manufacture and maintenance. So the figure of 80 g / mile is adjusted to 100 g / mile.
Other estimates
| g / km | g / mile | Source | Notes |
|---|---|---|---|
| 49 | 80 | [AEA, 23] | The most detailed source, and the one used as a basis |
| 49 | 80 | [CG, 10] | Recommended by CG, summarising several sources |
| 60 | 100 | [NEF, 2] | |
| 60 | 100 | [5] | |
| 60 | 100 | [16] | giving DEFRA as the original source |
| 70 | 110 | [ML, 6] | (underground) |
| 80 | 130 | [MH, 3] | (underground / metro) |
| 100 | 170 | [MH, 3] | (intercity) |
| 110 | 180 | [ML, 6] | (intercity) |
| 160 | 250 | [ML, 6] | (other) |
| 160 | 250 | [MH, 3] | (other) |
So the factor used by the Carbon Independent calculator is in the middle of the range of published estimates.
References
See Reference List