At the end of the previous decade slow steaming was already on the agenda. The reason at that time, during the economic crisis, was mainly overcapacity: less speed means that more ships are needed. Another reason was cost reduction: engines running at less power need disproportionately less fuel. Now slow steaming is again at the agenda. But the reason is different: climate change and the need to reduce greenhouse gas emissions.
In the 2015 Paris Agreement it has been agreed that global warming shall be limited to 2 degrees Celsius by the end of the century, and preferably to 1.5 degrees Celsius. Ships and airplanes largely contribute to the carbon emission and thus action is needed. In 2018 the countries united in the IMO (International Maritime Organisation) agreed that carbon emission by ships must decrease by 40% in 2030 and total emissions by 50% in 2050, the ultimate goal being no carbon emissions by then at all.
A step in the process is the global Sulphur cap of 0.5% as from January 1, 2020. But that is only a small step. Much more is required.
On 30 April 2019, more than 100 shipping companies and 9 environmental organisations addressed an open letter to the IMO asking for mandatory rules on slow steaming. That this can add to emission reduction is a given: in 2012 for instance CE Delft, an independent survey bureau, issued a report on the environmental effects of speed reduction. The report concludes that a speed reduction of 10% results in an emission reduction of 19% and also reduction of nitrogen and black carbon. Other reports mention a reduction of 22% at a speed reduction of 12%. The figures are considerable and therefore this measure seems to be low hanging fruit.
However, the US, most North-European countries (including the Netherlands) and the big container carriers are against mandatory rules: they think this only distracts from the real issue and the need to take real measures. Even at today’s volumes of global trade it will be a huge challenge to attain the 2050 goals, but the prognoses are that carriage of goods by sea will have doubled or even threefolded by then, so that indeed only drastic measures can help reaching the goals.
Other arguments against mandatory rules or even guidelines are the effects this will have on the sailing schedules and on global trade and skepticism whether slow steaming will lead to an overall cost increase, taking into account longer transit times and thus more costs of crew etc. Also, ship’s engines and propellers have been designed to run at certain revolutions. Too much deviations therefrom may lead to quicker wear and the elimination of the fuel savings.
At last month’s IMO meeting in Paris the issue has been extensively discussed: and, not surpisingly, no conclusions came out of the meeting. It is therefore not to be expected that slow steaming will be a largely used instrument to lower emissions.