London Underground: carbon footprint per passenger-km
Live factor value
0.01549 kgCO2e per passenger-km
Source: UK DESNZ greenhouse-gas conversion factors, 2026 (revision 2). Factor set desnz-2026-r2.
The London Underground runs entirely on electricity, and its official emission factor — published per passenger-km in the DESNZ 2026 conversion factors and shown live below — tracks the carbon intensity of the UK grid downwards each year. It is among the lowest-carbon motorised transport modes in the country.
High occupancy is the other half of the story: emissions per passenger stay low because each train-km is shared across hundreds of riders. A typical Zone 1–3 commute produces only a few tens of grams of CO2e each way.
Worked example
A typical 12 km Tube commute (one way): 12 × 0.01549 = 0.2 kgCO2e.
Measure your own with the free travel calculator.
Frequently asked questions
- Is the Tube lower-carbon than the bus?
- Per passenger-km, yes — the Underground's electric traction and high occupancy give it a lower official factor than local buses, and both are far below single-occupancy car travel.