Sulphur pollution study reveals shipping’s huge CO2 emissions

A study analysing options for reducing the shipping industry’s releases of sulphur dioxide has revealed a huge increase in its carbon dioxide emissions. The IMO is taking action to reduce emissions of both gases but the rate of progress is glacial.

The shipping industry’s carbon dioxide emissions have risen 150% over the past ten years, according to a study primarily designed to address emissions of another problem gas, sulphur dioxide.1 Environmental groups and the EU have become frustrated with the UN International Maritime Organization’s rate of progress on both gases.

The SO2 study was carried out by an ‘informal cross-government/industry scientific group of experts’ established by the IMO following a meeting of its Marine Environment Protection Committee (MEPC) in July 2007. The group complied data on the merchant shipping industry’s fuel use and emissions, and looked at the wider implications of the various options put forward for reducing SO2 emissions.

The final report, released at a meeting of the IMO’s sub-committee on Bulk Liquids and Gases (BLG) in February, shows shipping CO2 emissions reached 1.12 billion tonnes in 2007 and forecasts a 32% increase by 2020 under a business-as-usual scenario.

The 2007 figure already represents a 150% increase from 1996, the last year for which detailed data on greenhouse gas emissions were compiled. As a result, shipping’s share of global emissions has risen from 1.8% in 1996 to more than 4%.

The IMO is updating its greenhouse gas emission figures and had planned to have a new dataset ready by July 2009. But it announced in November it was looking at speeding this and other climate change measures. Addressing the IMO council, secretary-general Efthimios Mitropoulos acknowledged the urgency with which other sections of the global community are addressing climate change and said the IMO needed to be seen to act.

A considerable number of proposals have been submitted for discussion at the next meeting of the MEPC to be held in late March and early April. These apparently include the introduction of speed limits, improved logistics planning, indexing ships on the basis of their efficiency and an emissions trading scheme.

But the IMO will have to act uncharacteristically fast if it is to make up for lost time. Shipping has so far escaped much of the negative publicity attracted by the more public-facing aviation sector, but is increasingly seen as a laggard.

Demand for shipping is so high that most operators see little advantage in appearing greener, said Eelco Leemans of the Dutch North Sea Foundation. But this could change as more ships are built and if a recession reduces transport demands.

Actions through the IMO are hampered by the usual difficulties associated with reaching a consensus between 150 member states. There are additional problems with ‘flags of convenience’ countries like Panama and the Cayman Islands that are anxious to keep the industry happy at all costs. Such countries typically demand ever more research to delay any firm measures, said Mr Leemans.

The ease with which operators can switch to more accommodating nations also makes regional measures hard to enforce. Parties to the UN Framework Convention on Climate Change have, for instance, discussed bringing shipping under its control. But this would create a disparity between ships registered in developed annex I countries, which would be subject to emissions targets, and the majority registered elsewhere.

Mr Leemans thinks the answer is a straight-forward distance-based charging scheme, managed by the IMO, to encourage firms to think twice before running ships. Most of the technical solutions put forward would not be substantial enough, he said.

But Dragos Rauta, technical director of the International Association of Independent Tanker Owners (Intertanko), thinks there is a lot more that can be done to improve engine and overall ship efficiency. Intertanko is already participating in cross-industry working groups on efficiency, he said, and is encouraging its members to monitor their emissions.

"But at the end of the day, one has to remember ship operators are people doing transportation - not ship design," he added.

Niels Bjorn Mortensen, head of the marine department at Danish-based shipping association Bimco, made a similar point. The industry is very large and fragmented, much more so than aviation. The easiest point in the system to force a change would be in the design of new ships, perhaps through a set of international standards, he suggested.

However this process is not likely to bring change fast enough to satisfy the European Commission, which has threatened to include shipping in the EU Emissions Trading Scheme.

The head of the environmental directorate, Mogens Peter Carl, told the European Parliament in February that the Commission would issue "concrete proposals" by the end of the year if none were forthcoming from the IMO.

Delegates at the forthcoming MEPC meeting will also try and narrow the options for cutting SO2 emissions. The IMO hopes a final conclusion will be reached by the autumn.

The IMO’s expert group considered various options for reducing SO2 emissions but the BLG meeting in February whittled these down to three:

  • significantly tightening the current global cap on sulphur content in fuel
  • maintaining the current global cap but tightening limits in designated sulphur emission control areas (SECAs)
  • moderately lowering both the global cap and SECA limits and introducing "micro-emission control areas" with even stricter controls than the SECAs

The global fuel sulphur cap is currently 4.5% and the first option envisages cutting this to 0.5% from 2015. The second foresees a 0.1% cap in SECAs from 2012. The third suggests a global cap of 3% from 2012, a SECA cap of 0.5% from 2015 and micro-emission control areas with a 0.1% standard.

Intertanko was disappointed to see its proposal - a wholesale switch from heavy fuel oil to lighter distillate fuels - dropped by the BLG. It felt this would send a strong signal to other regulators and be simpler than the other options, which would generally require ships to carry multiple fuel loads or fit scrubbing units.

The expert group’s study shows the distillate option to be the most efficient - cutting projected SO2 emissions to a third of their 2000 level by 2020 and particulate emissions by around half. But a wholesale switch would be unpopular with oil refiners who would have to restructure their processes at an estimated global cost of $126 billion.

Bimco thinks a switch on this scale would be impractical and disrupt world trade. Mr Mortensen instead favours a gradual change through the multi-standard option. Ships visiting SECAs already carry three fuel types: heavy fuel oil for deep water, lower sulphur versions for the SECA and distillate fuels for standby mode. The IMO’s third option would make good use of the available fuel mix while refiners move to lighter fractions, he said.

Christer Agren, director of Swedish NGO Secretariat on Acid Rain, believes the rate of progress justifies his organisation’s long-standing pleas for regional regulation. Ships in EU ports will have to meet the EU sulphur Directive’s 0.1% fuel sulphur cap by 2010 but he would have liked the EU to have acted ten years ago.

Even now, a process originally scheduled to finish by the end of 2007 is dragging on. And consensus on the remaining three options could be hard to achieve, he notes, especially as the IMO has said the final solution could be a combination of the three and that the target years remain open for debate.