Climate Action —Air Travel

Air travel

Emissions per passenger-km

Berners-Lee estimates 3.5 tons of emissions for a return flight in economy class from London to Hong Kong (19,300km). That works out at 181 grams of emissions per passenger-kilometre.

The UK

Berners-Lee estimates that in the UK personal flights account for about 8% of 13 tons, or 1.04 tons of emissions a year. Using the conversion factor from the methods article, cutting out such a flight each year would reduce the 2100 temperature on the Little Planet by 0.11 °C.

International flights are not included in emissions figures for most countries. Source.
  • About 59% of people in the UK don’t fly at all.
  • About 41% of people in the UK fly on average 14,000km a year.

The US

  • About 52% of people in the US don’t fly at all.
  • About 48% of people in the US fly on average 10,400km a year.


Standard economic theory provides a good case for letting people carbon offset their flights. The problem is that in practice it doesn’t work. I looked through the four largest US Airlines; two of them, Delta and United, let you offset your flights via their partners Conservation Coast and Conservation International. If you click on those links, you’ll see they’re running projects verified by Verra’s VCS program, which is the largest carbon offsetting program in the world.



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