Sending goods by sea is the norm. And, if you’re worried about CO2 emissions, you’ll initially be glad to hear that according to the World Shipping Council “Maritime shipping is the world’s most carbon-efficient form of transporting goods – far more efficient than road or air transport.” . They give figures of 10 grammes of CO2 to move a tonne of goods one kilometer. To do the same by rail (diesel train) takes 21, truck and trailer 59, and by air the figure is 470 grammes. But of course an electric train, depending on the source of the electricity, might do better, as might an electric truck in the future. The main problem is that world trade is so big that, even though most of it goes on ships, the total CO2 emissions are enormous. (So are other pollutants: the fifteen largest ships produce more Nox and SO2 than all the cars in the world).
What can be done? The International Maritime Organisation, a UN specialised agency, has a target of reducing CO2 emissions from world shipping by 50 per cent by 2050. Continued technical progress in ships, engines, and fuels will all play a role. But there are also big benefits from ships going more slowly. This has been an increasing trend in any case as a cost saving measure, but it also reduces the CO2 emissions. An obvious additional step is to start taxing maritime fuel, which at the moment, like aviation fuel, is not taxed at all. The IMF has been looking at this and is quite excited about it:” In short, maritime carbon taxes are an economically and administratively promising instrument”
Further steps to take include the electrification of rail lines, which opens up the possibility of using alternative energies in rail freight. What about trade wars? New tariffs on trade and “bringing the jobs home” should cut down on international sea freight, shouldn’t it? Well, producing locally of course reduces the need for imports and thus for freight. But it is almost certainly not the most efficient way to go. Tariffs impose a cost on consumers and they hinder growth and this means that there will be fewer resources for combatting climate change or for anything else.
There’s another development, an unfortunate by-product of climate change that may actually be useful. With global warming, new sea routes are opening up in the Arctic, the fabled Northwest and Northeast Passages. They could halve the time of sea freight voyages between some big markets.