Goods and people have been transported by sea throughout human
history. In the modern world, shipping remains the most efficient
method for moving cargo where speed is not a major concern. Large
quantities of material can be moved using relatively little fuel
compared to alternatives such as road haulage, trains, and
aeroplanes. Shipping makes up approximately 80% of the EU's
imports and exports by volume, and the International Chamber of
Shipping estimates that 1.5 tons of cargo per person per year are
carried by sea worldwide.
Commercial shipping is almost entirely powered by fossil fuels.
As a consequence, maritime traffic is estimated to produce
approximately 3% of global carbon emissions. Significant work is
therefore being focussed on technologies that can reduce emissions
from the maritime sector as part of wider efforts to decarbonise
the world economy.