We often say that CO₂ emissions from shipping are hard-to-abate but 40% by weight of what we ship is fossil fuels so it should get easier when we decarbonize.

Some of that will be replaced by 'energy products', high energy input things that can be shipped. A way to import embodied energy. DRI Sponge iron ORMDRI steel, metals, methanol (feedstock and fuel use), fertilizer, and many, many others come to mind.

But rising demand for green hydrogen will also increase demand for shipping, no?