Now that I'm not flying any more, I need to figure out ways to get to places where I'd usually travel by plane.

For example, I'm travelling to the Netherlands next month. Fortunately, instead of having to go down from the north of England, through London, and then across to Paris and then Amsterdam, I can take the ferry.

But what about the carbon emissions of ferries? Thankfully, for foot passengers they are, on average, even smaller than those of coaches.

Emissions from different modes of transport

Train virtually always comes out better than plane, often by a lot. A journey from London to Madrid would emit 43kg (95lb) of CO2 per passenger by train, but 118kg by plane (or 265kg if the non-CO2 emissions are included), according to EcoPassenger.

[...]

The [Department for Business, Energy and Industrial Strategy] has also put a figure on ferry transport - 18g of CO2 per passenger kilometre for a foot passenger, which is less than a coach, or 128g for a driver and car, which is more like a long-haul flight.

Source: Climate change: Should you fly, drive or take the train?