Thanks to Owen Petchey who compiled this information in April 2023.
Bottom line
– If you live close (e.g. within a few hours land travel) to a ferry port that serves Helsinki (e.g. Stockholm, Travemünde, Tallinn) then it may be worthwhile not flying.
– If you live some distance from such a port, then the combination of train and ferry could easily be so much more expensive that flying that the flight carbon cost could be several times fully offset by the cost difference.
Some details and examples
Carbon per km costs: https://ourworldindata.org/travel-carbon-footprint
Short-haul flight: 156g per km
Train: 41g per km
Ferry: 19g per km
Flying Zurich to Helsinki return
- 3600 km
- Economy class
- 0.5 t CO2
- Other estimates: 0.65 t CO2 0.996 t CO2
- Cost: Swiss 595 CHF; other 300 CHF
- Cost to offset:
- 23 Euro 100% offset (atmosfair.de)
- 60 CHF x 2, 80% offsetting, 20% SAF.
Zurich (train) Travemünde (Germany) (ferry) Helsinki
Train Zurich to Travemunde
- 10 hours train
- Cost unknown
Ferry Travemünde (Germany) (ferry) Helsinki
- 29 hours
- Return with cabin, 939 Euros
- Appears difficult for foot passengers to embark and disembark
Zurich (train) Stockholm (ferry) Helsinki
Zurich to Stockholm train
- 24 hour (Overnight to Hamburg, Hamburg, Copenhagen, Lund, Stockholm)
- Cost unknown, probably 5-600 CHF if overnight to Hamburg taken.
Stockholm to Helsinki ferry
- Overnight, 16 hours
- 4 bed cabin
- Return in 4 bed cabin, 208 Euros
- Return in 2 bed cabin, 367 Euros