Traveling Thoughtfully

Some information to help

Carbon calculators used:

Carbon calculators vary in sophistication. For instance, Atmosfair’s climate impact calculator includes both the impact of carbon dioxide and methane emissions (“carbon equivalent”) as well as non-carbon emissions such as contrails and ozone. Please note I am not advocating buying their carbon offsets.

Keep in mind:

  • 5 metric tons annual carbon footprint of a person on earth (closer to optimal)
  • 8 metric tons average for a UK citizen
  • 18 metric tons average for a US citizen

(Sourced from the World Bank website at The numbers are from 2010 and rounded for ease of remembering)

All carbon footprints below include radiative forcing.

Per-person estimates for non-stop economy round-trip flights in US:

  • San Francisco to New York City: 1.3 metric tons
  • Boston to Miami: 0.6 metric ton
  • Seattle to Miami: 1.3 metric tons

The carbon usage is higher with intermediate stops because aircraft use a lot of fuel climbing to their cruising altitude.

  • Portland OR to New York City (non-stop economy round-trip): 1.2 metric tons
  • With one intermediate stop in Chicago (not uncommon!): 2.5 metric tons

Per-person estimates for non-stop economy round-trip international flights:

  • Seattle to Amsterdam: 2.4 metric tons
  • Los Angeles to Guangzhou: 3.5 metric tons
  • New York City to Melbourne: 5.0 metric tons

Since business and first class passengers use more room than economy passengers, their per-person carbon-equivalent estimates are proportionally greater. For example:

New York City to Melbourne:

  • economy: 5.0 metric tons
  • business: 14.6 metric tons
  • first: 20.1 metric tons