Historically, marine transport harnessed the power of wind and/or people to transport goods, foods and people in bulk around the planet.

Modern shipping relies heavily on fossil-fuelled vessels which are more predictable, but have a much higher carbon cost. Renewable energy resources such as sun, wind and wave power are highly abundant at sea, so it should be possible to make better use of these resources in the future.

The oceans and seas of the world are an important part of the global carbon cycle and their potential for helping us redress the carbon balance is exciting. However, the effect of increased atmospheric carbon could also damage marine life (increasing acidity in the oceans could make it hard for organisms to maintain their exoskeletons for example). - Description added by: David Lockie