A new measurement method shows that the correct figure is almost twice as large as the one previously calculated, meaning domestic shipping has a greater environmental impact than domestic flights, reports SVT News.
The Swedish Meteorological and Hydrological Institute (SMHI) has compiled the new figure, by tracking all vessels that go between Swedish ports with the help of GPS data.
"We see about twice as high fuel consumption from domestic shipping compared to what we previously thought, and thus twice as high emissions, says Fredrik Windmark, air quality expert at SMHI, to Radio Sweden.
According to the new survey method, domestic shipping accounted for 662,000 tonnes of carbon dioxide equivalent in 2016, of which commercial traffic accounted for 488,000 tonnes with the remainder from recreational boats. This can be compared with domestic air traffic, which emits 554,000 tonnes.