At seven o’clock on the 8th of June, 2012, this is where the world’s ships were:
That’s an image from Kiln‘s fascinating ShipMap, which shows the movements of the global merchant fleet through 2012. It’s beautifully visualised, and gives a real sense of movement and flow. Up at the top though, it also shows the CO2 emitted as all those container ships and tankers go about their business.
That may not be as much CO2 as you think. Shipping only accounts for 3% of global emissions, and as an international issue that doesn’t fall within anyone’s jurisdiction, it was left out of the Paris agreement. But that 3% is still significant, because it’s growing. International shipping has already grown by 400% in the last 45 years, and it is forecast to grow by 250% by 2050. At that point it will account for 14% of global emissions.
Except that, as we’ve seen before with meat and with construction materials, what looks like a carbon sideshow gets more serious when you’re working with a gradually shrinking carbon budget. Since we have to reduce emissions by 80%, shipping would be enough to tip us over 2 degrees of warming single-handedly.
The industry is aware of this, and is working on ways to lower emissions. Possible actions include running ships in port off local amenities rather than keeping the engines running, hybrid power that uses sails or kites, or heat recovery systems. An international carbon levy on shipping would help. Modern ships are already much more efficient, and there is potential for LPG or even nuclear powered vessels in future.
The industry has been working to reduce CO2 by 20% by 2020, but at that rate of change, improvements in efficiency will be lagging behind growth. Unless we invent the teleporter very soon, we’re going to have no choice but to ship less stuff across the world.