We need to stop shipping things across the world for economic reasons. We need to produce and buy locally. The truth is, the global economy has to crash and rebuild itself if we want an eco friendly future. Worldwide shipping needs to go away. Commercial aviation needs to go away. These are things no one wants to hear but would do the most good. Sacrifice is key. We may need to live modestly for a generation in order for energy production to advance to the point where we no longer have to. Our modern growth is a result too hastly adopting dirty technologies.
They are efficient (cargo vs fuel consumption). They also go through my regular car’s full gas tank in about 30 seconds. Less ships means less fuel burned. If we produce locally, transportation is not needed.