Efficient Ocean Shipping
More than 80 percent of global trade, by volume, floats its way from place to place. 90,000 commercial vessels—tankers, bulk dry carriers, and container ships—make the movement of goods possible, transporting more than 10 billion tons of cargo in 2015.
Shipping produces 3 percent of global greenhouse gas emissions. Forecasts predict they could be 50 percent to 250 percent higher in 2050. Because of huge shipping volumes, increasing shipping efficiency can have a sizable impact.
Efficiency begins with ship design and onboard technology. Fuel-saving innovations include:
- flat extensions called ducktails at the rear to lower resistance; and
- compressed air pumped through the bottom of the hull to create a layer of bubbles that “lubricate” passage through the water.
Maintenance and operations also are vital for marine fuel efficiency. Techniques like removing debris from propellers, smoothing the surface of a hull with a sharkskin-like coating, and “slow steaming”—reducing a ship’s operating speed—all lower fuel consumption.
A combination of a selection of 17 ship technologies with slow steaming (literally slowing the ship speed) can help reduce fuel consumption of ocean ships of a variety of types. This fuel reduction can be on the order of 50% of today’s consumption rates across the international shipping industry, and if adoption grows to 57-78 percent of international ships, can lead to a 4.4-6.3 gigaton reduction of carbon dioxide emissions by 2050 at cost of $530-733 billion. That could save $620-876 billion in fuel costs over the life of the ships.