Last reviewed 4 January 2017

Aviation and shipping combined have long been a major source of greenhouse gases (GHGs). While flight has flown into the spotlight recently, shipping by its distant nature largely escapes scrutiny. Jon Herbert looks at how the industry is facing up to change and whether the EU will have to step in.

Surprisingly, Southampton has one of the worst air pollution problems of any UK city. The reason is its port. Ocean-going vessels berthed for days and weeks at a time use bulk power from their own diesel generators. The resulting emissions flow out over Southampton.

Rogue emissions are a high seas problem too. Which is why change is being forced slowly into the world’s shipping fleet.

Shipping produces more GHGs than aviation, rail and bus transport together. The world’s 90,000 large commercial vessels consume circa five million barrels of petroleum products daily. Without change, their emissions are on course to rise by up to 500% by 2050.

Some interim reduction targets have been set. Under UN auspices, maritime nations have “agreed to try to agree” on a full reduction strategy by 2023. However, no details have been given; progress is extremely slow.

Action could be taken

Market forces have so far failed to trigger change. One example relates to low oil prices. It is now viable financially for some ships to avoid Panama and Suez Canal tariffs by sailing the long way around South America and Africa — with higher emissions.

However, there are short-term steps that could be taken quickly. Polishing ship propellers can reduce emissions by around 8%. So-called “slow steaming” cuts water and wind resistance, plus fuel use, with carbon dioxide (CO2) emissions falling by up to 30%. Speed limits could be monitored digitally using transponders and policed by the countries which “flag” vessels.

Reducing ship speeds by 10% can also cut emissions by circa 27%, with additional NOx and particulate matter (PM) falls. Benefits greatly outweigh costs but delivery times suffer. The world’s largest container shipping company, Maersk, has been slow steaming since 2007 and reports fuel savings, low maintenance costs and fewer operating problems. “Super-slow” steaming could cut engine power requirements by up to 90%, with pro rata gains.

However, no-one else seems very keen to act. Two-thirds of the world’s ships are registered in small non-industrial states like Panama, Liberia and the Marshall Islands.

Longer-term measures could include imposing a carbon tax for every tonne emitted equivalent to the cost of environmental damage caused, a concept that applies to other industries.

At the helm is the UN expert group, the International Maritime Organization (IMO). It has estimated that in 2007, world shipping was responsible for circa 2.7% of global carbon emissions. With domestic shipping added, this rose to 3.3%. However, emissions are climbing quickly. Without regulation, this is forecasted to grow to 1475 million tonnes by 2020 — 6% of the total. The mid-century projection is far, far worse. By 2050, a 2015 study for the European Parliament calculated that without regulation maritime emissions could account for 17%.

Shipping was exempted from the 1997 Kyoto Protocol target because fitting the peripatetic industry into any obvious model is difficult. For example, who pays for CO2 reduction costs – the country of origin, the destination nation, or the shipper? However, that doesn’t excuse developed countries from making progress through the IMO, though progress has been exceptionally slow.

One avenue is new energy-efficient criteria for ship construction. However, targets are said to be unambitious, with no binding GHG reduction commitments for the world’s existing fleet.

However, the EU has created an alternative regional system for monitoring, reporting and verifying (MRV) ship GHG emissions designed to lead to more ambitious ship design, operation, fuel efficiency and renewable technologies.

Final straw

Despite a commitment to review the situation proactively, November 2016 saw the IMO decide to delay any decision on GHG cuts by at least seven years. IMO work in this field first started in 2003 but halted in 2011. Even though 115 nations ratified the Paris climate agreement in October 2016 to limit global warming to no more than 2°C, and preferably 1.5°C, as a matter of urgency, shipping has opted for a new process that will result in more talks.

Another approach to emission cuts is the development of standards and guidelines for the design and construction of sleeker ships. The International Chamber of Shipping says better-designed engines, hulls, and propellers could cut emissions by a further 15% to 20%. The current standard is said to be too lax to be effective; a revision will not now take place until at least 2018.

The Energy Efficiency Design Index (EEDI) regulates the energy or fuel efficiency of new ships. It was agreed in 2011. Yet, its remit is said to be so gentle that many ships afloat already meet its demands with ease and are still climate target offenders. At least two-thirds of the world’s containerships, 50% of general cargo vessels and 25% of tankers launched during 2015 met and exceed the 2020 regulations without even using the new technologies developed to improve climate efficiency. It is even said that far from stimulating the uptake of vital innovative new technology, all the standard achieves is preventing a slide back into bad old ways. Another observation is that efficient ship design fluctuates with economic cycles and fuel prices.

Enter the EU

Waiting another seven years could be the last straw for the EU. Members of the European Parliament Environment Committee want the EU to step into the gap. They want the EU to continue applying its own law on the transparent collection and reporting of MRV CO2 emissions data.

Seven MEPs have said it is time for the shipping industry to play its role in Europe’s transition to a low-carbon society. They stress that time is of the essence. Without IMO action, they say ship emissions must be included within EU 2030 climate targets. The idea is that by setting up a climate fund for shipping — a levy — Europe can help force the sector to cut CO2 cost-efficiently in line with industry in general. This would involve ship owners buying emissions trading system (ETS) allowances from 2021. Alternatively, they could pay an equivalent sum into a new fund buying ETS allowances on their behalf, part of which would feed back into new low-carbon technologies.

The significance of data has been stressed, along with concern that IMO information is not being shared freely with authorities, ports and shippers. Conversely, the IMO has also come under fire for asking for the EU’s system to be closed down.

Last September 2016, the IMO’s then Secretary-General Koji Sekimizu said shipping emissions should not be capped because it would damage economic growth. “Such measures would artificially limit the ability of shipping to meet the demand created by the world economy, or would unbalance the level playing field that the shipping industry needs for efficient operation, and therefore must be avoided,” he said. This, says the EU, would thwart decarbonisation objectives. It also points out that the longer cuts are delayed, the larger they will have to be.

Road map

A route to sustainable decarbonisation has been mapped out by the Sustainable Shipping Initiative (SSI) with key markers listed to meet 2040 ambitions. Some 17 leading shipping lines are involved. They point out that rising sea levels in ports and greater extreme weather risks are hazards for the whole industry.

Energy savings are a key concern. A switch from fuel oil to greener alternatives is encouraged. Global shipping emissions could be cut by 80% to 90% per tonne/mile by 2040 over 2012, it says, with milestones of 20% by 2020 and 50% to 70% by 2030.

Slow steaming, clean shore power supplies (the Southampton example) and advanced power management systems could make major improvements. But no firm emissions reduction target has been set yet. However, real-time monitoring of all ship functions is on the agenda. SSI hopes the IMO will pick up this goal and run with it.

Facts and figures

The Third IMO GHG Study projects that a 2.7% contribution to world CO2 emissions from shipping could increase by 50% to 250% by 2050. Emissions are already up by circa 70% since 1990. If other economic sectors cut their carbon emissions, shipping could eventually represent 10% of global GHG releases by 2050, this study suggests.

With regard to EEDI, different classes of ships have different efficiency targets, but the overall impact of new vessels between 2015 and 2019 should be 10%. Ships built from 2020 to 2024 must improve efficiency by between 15% and 20%. Post-2024, the target is 30%.

Unfortunately, ships built post-1990 are now less efficient; vessels built in 2013 are on average 10% less fuel-efficient than their counterparts 25 years ago.

Cleaner fuel success

However, an agreement to cap sulphur content of marine fuels to 0.5% by 2020 that could prevent hundreds of thousands of premature deaths is seen as a shipping sector success.

Current sulphur limits are 3500 times higher than for diesel cars and lorries in Europe. At present, shipping is the world’s largest SO2 emitter after China. Target reductions will be 85% over today’s levels; contributions to world levels will fall from 5% to 1.5%. However, how the cap will be implemented and policed is yet to be announced.