Shipping is one of the fastest growing and most heavily polluting industries.
Shipping fuel releases ultra-fine soot particles which can damage health, as well as various global warming pollutants including black carbon from incomplete fuel combustion, nitrogen oxides, nitrous oxide and of course CO2.
Despite the recent introduction of mandatory efficiency targets for shipping vessels, these do not come into force until 2015 - and many of the restrictions can be circumvented.
Reducing industry's environmental impact will clearly take a long time.
A Swiss-led venture, PlanetSolar, is attempting to change the direction of future maritime travel with Tûranor, the world's largest solar-powered sea vessel.
The 31-metre-long catamaran, which is covered with 600 square metres of photovoltaic panels, stores solar energy in the world's largest lithium ion battery. It drives the vessel's silent, pollution-free electric motor, which can continue to operate in the absence of sunlight for around three days.
The ship's name, inspired by Tolkien's Lord of the Rings, means "power of the sun".
Its creators believe that high-performance solar mobility can be realised today by making innovative use of existing materials and technology, and they aim to take an active part in advancing research in renewable energy.
As Raphaël Domjan, the project's pioneer explains: "We want to be the Phileas Fogg of the 21st century... our project is meant to serve the environment and to enable solar energy to replace fossil fuels, and to motivate engineers and scientists to develop these technologies".
In December 2010, the Tûranor began an epic 19 month voyage in a bid to become the first entirely "solar" vessel to circumnavigate the globe.
Assisted by French meteorologists, the crew of four chose the most efficient course according to weather conditions, following an equatorial route to maximise sunshine.
For this segment of Earthrise, Oliver Steeds boards the Tûranor in the Red Sea to join the crew for a leg of this historic voyage.