On Carbon Emisisons: The shipping industry as a whole emits roughly the same CO₂ annually as Germany. It is the most fuel-efficient method of moving cargo ever devised — per tonne per mile it beats road freight by a factor of around fifty.
(Whilst shipping is exceptionally green on a per-unit-moved basis, the emissions as an absolute number are vast, and this has kled to some people calling for bans on shipping. I posit that we need shipping more than Germany, though, so if we need to make drastic reductions in carbon, let's ban Germany and keep the ships instead).