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We propose establishing and enforcing speed limits for commercial shipping in order to reduce fuel consumption and consequent CO2 generation


Guidance on collaborative pilot

This is a pilot test of a new, collaborative approach for getting work done in the Climate CoLab. It will run during March and April of 2012.

Just like in the 2011 activities, anyone can create a proposal. But there is also a community proposal, where members are encouraged to work together in a collaborative way. Any member can contribute to the community proposal as long as they are logged in.

The community proposal is like a wiki, so the history of edits is tracked, and you can revert to prior versions of the proposal if desired.

Please also use the Comments to express your opinion on whether or not you would like to see this collaborative approach used in the Climate CoLab in 2012.

Feel free to organize the proposal as you see fit. One thought—it's good to have a brief summary of the overall proposal at the top, as an aid to readers.

Proposal Text


Carbon dioxide emissions from commercial ocean & inland shipping is estimated to be 4 to 5 percent of the global total, and estimated to rise by up to 72 percent by 2020 if no action is taken. Studies show that one of the most effective means of reducing fuel consumption is by reducing the speed as which ships travel. Engine power output (and therefore fuel consumption) is a third power function of speed. Based on sea trials and design calculations, the ship building yard determines the 'economical speed' for all ships i.e. the speed at which fuel consumption per nautical mile is minimum.

In times of low demand, ships often operate at economical speed in order to reduce costs, however when demand is high, they run at the maximum possible speed which means singnifcantly higher fuel consumption and emissions. If international regulation is put in place to define speed limits for ships, whereby they always operate at or as close as possible to their economial speed, a large reduction in fuel consumption could be realized.

Category of the action

Reducing emissions from transportation

What actions do you propose?

  • Determine the average economical speed of existing world shipping tonnage.
  • Factor in economical speed for ships presently in the construction or design phase.
  • Calculate and propose a speed limit for ships that can be applied globally and is as close as possible to economical speed for all ships.
  • Seek global agreement through international and industry bodies such as the International Maritime Orgainization (IMO), International Chamber of Shipping (ICS), Oil Companies International Marine Forum (OCIMF), International Association of Classification Societies (IACS), various Flag States and Port States.
  • Determine monetary fines for breech of speed limits that are high enough to encourage compliance yet give the shipper the option to pay the fine in extenuating circumstances where speed limits must be broken. Fines could be benchmarked against air freight rates.
  • Let the port of arrival and/or departure be the primary means of enforcement. In order to get ports to buy into the process, they can be given a percentage of fines collected towards improving and expanding their facilities and infrastructure.
  • AIS (Automated Identification System) is fitted on most ships. It gives real-time information about a ship's speed and course and can be used as a means of monitoring and enforcement.
  • Additional benefits could be derived from voyage optimization, weather routing, and mandatory hull and propellor cleaning at regular intervals.

Who will take these actions?

Where will these actions be taken?

Action willl be taken at the port of arrival and departure for all ships. Ports will assess the average speeds for the total trip and use the Automated Information System (AIS) currently housed on most commercial vessels to enforce instantaneous speeds. 

How much will emissions be reduced or sequestered vs. business as usual levels?

What are other key benefits?

Lower shipping speeds and increased lead time may encourage consumers to source products from locations closer to home, thus making the entire supply chain more sustainable.

Shippers may see the benefit of using newer ships that use modern design and engine technology and are therefore more efficient.

What are the proposal’s costs?

Time line

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