Slow steaming saves money and the climate

Photo: Louis Vest/ CC BY-NC

Regulated speed reduction is a cost-effective and practical way to reduce greenhouse gas emissions and air pollution from shipping.

International shipping accounts for around three per cent of global CO2 emissions. Shipping emissions will grow as world trade grows and, together with aviation, are estimated to comprise 4 to 5.7 per cent of global CO2 emissions in 2020 (UNEP) and some 10 to 32 per cent in 2050 unless action is taken. The International Maritime Organization (IMO) has been discussing what to do since it was tasked with reducing emissions from international shipping by the 1997 Kyoto Protocol. An IMO action plan on market-based measures is now in its 10th year and IMO remains many years away from having a measure in force.

A good number of policy options, ranging from emissions trading, a global carbon levy, to efficiency trading and mandatory emission reductions by ship have been proposed, debated, studied and amended during this time and remain under consideration. The Energy Efficiency Design Index (EEDI) for new ships and Ship Energy Efficiency Management Plan (SEEMP) for existing ships were agreed in 2011 and enter into force on 1 January 2013.

At the IMO’s Marine Environment Protection Committee (MEPC 61) in September 2010, the IMO considered a proposal from the Clean Shipping Coalition (CSC) to apply speed restrictions to ships to reduce emissions of CO and other pollutants, with CSC noting that average ship speeds have crept up over the past 20 years despite rising fuel costs and that fuel consumption and thus emissions are a cubic function of speed. The IMO declined on this occasion to consider the issue further but feedback in the corridors of the meeting led two of the CSC members – Seas At Risk and Transport & Environment – to commission a study to investigate further and underpin the legal, environmental and economic feasibility of regulated slow steaming i.e. slow steaming at or beyond the level that companies initiate themselves.

Slow steaming, first practiced in the 70s, is a relatively recent phenomenon, being widely adopted as a response to the slump in demand and oversupply of ships that accompanied the start of the current economic crisis. The practice has been further extended since 2008 and has brought widespread benefits to shipping companies who have now embraced it as a useful operational measure to lower fuel costs.

Slow steaming has resulted in a significant reduction in emissions of GHGs and air pollution. However there is a widespread expectation in the industry that as the economy and markets pick up and excess capacity is brought back into service, speeds will increase again over time to meet the growing demand. If this occurs, we can expect a significant and sustained increase in ship emissions just at the time when long-term IMO initiatives to address shipping’s carbon footprint are hopefully reaching a conclusion. Capping speeds at or around their current crisis levels – which estimates suggest could be 10–15% below their 2007 maximum – would prevent this from happening and avoid a market speed up, largely negating the effect of any long-fought-for climate measure the IMO might adopt.

Speed restriction in the road and rail sectors is commonplace – mainly for safety but also for environmental reasons. Industry has however argued strongly that restricting speed in the shipping sector is not appropriate as it limits flexibility and will have negative implications for safety, logistics and costs, and result in a poor environmental outcome due to the need to build and operate additional ships.

The joint SAR/T&E study – conducted by CE Delft, Professor Mikis Tsimplis and The ICCT – effectively dismisses all the common concerns surrounding speed limitation as unfounded (see box). Moreover it clearly demonstrates that regulated slow steaming not only reduces CO2 and other emissions dramatically, it actually saves the sector money. Implemented carefully – e.g. by including certain provisions for ships that need to travel faster – such an intelligent approach to regulated slow steaming would provide industry with the flexibility they say they need. Such a provision could also be constructed in a way that raised revenues, which could be used for climate change purposes.

When the Clean Shipping Coalition raised the issue of regulated slow steaming at the IMO in 2010, the idea was dismissed with very little discussion. Yet slow steaming has proven to be the only effective measure that has actually delivered significant in-sector emission reductions over past years. The industry may soon be on the verge of seeing average speeds increase again, potentially negating all those emissions reductions. The CE Delft study looks carefully at all the concerns about speed limitation and we believe provides the necessary background to enable the IMO to revisit the issue. The report of the study and a proposal from CSC have been submitted to IMO and will be considered at MEPC64 in October 2012.

Regulated slow steaming can produce emission reductions by 2030 and 2050 that rival any other reduction option being considered at IMO or EU level. And it can do so with a sizeable economic gain. If we are serious about tackling shipping GHG emissions and making sure that the shipping industry contributes its fair share to tackling climate change, then the IMO – and industry – must take regulated slow steaming seriously and give it full and proper consideration.

John Maggs, Seas At Risk and Bill Hemmings, Transport & Environment  Members of the Clean Shipping Coalition

Highlights from the Study

  • Slow steaming has significant multiple environmental benefits. A 10% reduction in fleet average speed results in a 19% reduction of CO2 emissions even after accounting for the emissions of additional ships needed to deliver the same amount of cargo and the emissions associated with building the necessary additional ships. Emissions of SOx, NOx and probably black carbon will decrease in line with fuel use and CO2 emissions. A ship speed reduction of 25% leads to a reduction in main engine fuel consumption of approximately 58% on a ship year basis. Fuel savings at the fleet level will be somewhat less, as explained in the report. Lower ship speeds will also reduce whale strikes and other harmful wildlife interactions.
  • Slow steaming has significant economic benefits. Taking into account both the direct costs (fuel use, crew, capital costs of ships), indirect costs (additional inventory costs, adjustment of logistical chains) and the external costs (impacts of emissions on human health and ecosystems, climate impacts), the benefits of slow steaming outweigh the costs. This result is robust for a number of fuel price assumptions and discount rates. Implemented correctly, regulated slow steaming is cost-free to the shipping industry as a whole and entails marginal incremental logistic and supply chain costs to consumers.
  • There are very few, if any, evident technical obstacles to slow steaming. Many shipping companies have experience with slow steaming in recent years. Even at very low engine loads, they have encountered only a few problems and these problems could be surmounted by small changes to operational procedures. Hence, it appears that there are very few technical constraints to slow steaming.
  • Regulated slow steaming is legally feasible. Compulsory slow steaming can be imposed by a State on the ships flying its flag; on all ships in territorial waters (but can’t be enforced while the ship is in transit or innocent passage); and in the Exclusive Economic Zone (EEZ) and the high seas as a condition of port entry of the imposing States.
  • Regulated slow steaming is feasible to implement. Regulated slow steaming is relatively easy to monitor and enforce, and may have a lower administrative burden than some of the recently proposed MBMs. Speed can be monitored, both by ships and by regulators, and reported to regulators with little additional effort. Enforcement can be based on existing port State control instruments.
  • Regulated slow steaming delivers emission cuts in-sector. Regulated slow steaming ensures that emissions in the shipping sector will be reduced from business-as-usual levels, regardless of the fuel price and demand for shipping.
  • Regulated slow steaming could avert a spike in ship emissions as the global economy picks up. A cap on speed would reduce the possibility of an otherwise likely large and long-term spike in emissions if ships speed up in response to a recovery in demand. A cap set today around current average ship speeds will have little impact on industry.
  • Regulated slow steaming could apply at different levels. A global regime would potentially have the largest impact on emissions; a regional initiative, e.g. in the EU, would have a smaller impact. Regulated slow steaming in the Arctic could prevent an increase in black carbon (BC) emissions there as shipping activity increases when sea routes open; BC has a particularly strong climate effect when deposited on snow or ice.

Reference: Regulated Slow Steaming in Maritime Transport: An assessment of options, costs and benefits. A study commissioned by Seas At Risk and T&E and undertaken by CE Delft, The ICCT & Mikis Tsimplis. February 2012.


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