Map of global commercial shipping routes.
B.S. Halpern (T. Hengl; D. Groll) / CC BY-SA 3.0

It takes 5 million barrels of fuel per day to move commercial ships across the routes shown on this map. Added up over the course of a year, international shipping emits more than 800 million tons of carbon dioxide or its equivalent in other greenhouse gases—11 percent of the total emissions from the transportation sector.

Efficient Ocean Shipping

Reduce SourcesTransportation
CO2 Equivalent
Reduced / Sequestered
Billion $US
Net First Cost
(To Implement Solution)
Billion $US
Lifetime Net
Operational Savings
Huge volumes of goods are shipped across oceans. Fuel-saving ship design, onboard technologies, and operational practices can improve efficiency and trim emissions.

Solution Summary*

More than 80 percent of global trade, by volume, floats its way from place to place. Some 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
  • 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.

* excerpted from the book, Drawdown

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 percent 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 US$532–738 billion. That could save US$620–876 billion in fuel costs over the life of the ships.

Note: August 2021 corrections appear in boldface.