IIRC in terms of cost, a cargo ship costs $0.01 per kg per km, a train costs $0.03 per kg per km, and an airplane costs $0.60 per kg per km. Assuming things whi

IIRC in terms of cost, a cargo ship costs $0.01 per kg per km, a train costs $0.03 per kg per km, and an airplane costs $0.60 per kg per km. Assuming things which are environmental burdens are even a little bit correlated with costs, its not even a competition.