Often steaming in international waters far from land, the world's fleet of ocean-going ships has largely evaded scrutiny as a source of harmful air pollution and global warming emissions. But this lack of regulation is about to change as the fleet, which carries 90 per cent of trade, expands rapidly and pressure increases to impose tighter fuel standards, and others, on the trillion-dollar industry.
Calls are also growing louder to include both the shipping and aviation industries in any new international deal to cut greenhouse emissions. Neither are covered by the Kyoto Protocol, which expires in 2012. The cleanup proposals are being closely watched by major ports like Shanghai, Hong Kong and Singapore because they will add substantially to business costs. They could give other maritime centres a competitive advantage unless the new controls are adopted and enforced by all trading nations.
A report last month by four US environmental groups found that only six countries emitted more carbon dioxide, the main greenhouse gas, than the world's fleet of 60,000 ships. It said that, each year, the fleet released between 600 million and 900 million tonnes of carbon dioxide, about the same as the 130 million cars on US roads.
However, shipping industry officials say it is difficult to measure carbon dioxide pollution from the global fleet and that some estimates are exaggerated. A figure frequently cited by the industry is a report to the British government by former World Bank chief economist Nicholas Stern. It concluded that carbon dioxide emissions from ships contributed just 2 per cent to the global total in 2000, compared with 15 per cent from the transport sector as a whole. Critics insist that the level is substantially higher and fails to take account of the rapid expansion of seaborne trade, which has surged 50 per cent in the past 15 years.
Ships are also a source of non-carbon-dioxide pollution. The International Council on Clean Transportation, made up of transport and air quality officials from a wide range of states, reported last year that seagoing ships produced more sulfur dioxide than all the world's cars, trucks and buses combined. The council's study showed that the sulfur content of marine bunker fuel is far greater than highway diesel fuel. Bunker fuel is significantly cheaper than road fuel.
Environmental groups say that ships account for between 8 per cent and 10 per cent of sulfur emissions from all types of fossil fuel and also contribute nearly 30 per cent of global releases of nitrogen oxides. These emissions harm human health, cause acid rain and deplete the ozone layer.
Critics say that another pollutant from ships - black carbon, or soot - can warm the atmosphere many times more than the same amount of carbon dioxide.
In November, reacting to public concern about pollution from ships, the European Commission called on the International Maritime Organisation, the United Nations agency responsible for regulating shipping and marine pollution, to do more to help combat climate change. The IMO set up a scientific group in July to study the issue. The group included experts from major shipping and trading nations, including China, Japan and Singapore, as well as non-governmental organisations. Their report is due to be presented at an IMO meeting in London next month.
Any proposals to tighten fuel standards, reduce funnel exhaust gases and use only shore-based electric power when in port would be included as amendments to global marine pollution laws under the IMO's Marpol Convention. They could be adopted as early as October and come into force 16 months later.
Some ship owners and government officials have cautioned the industry to take a conservative approach to pollution cuts because of the potential costs involved. But Tony Mason, secretary general of the International Chamber of Shipping, warned that if governments and industry failed to come up with improved standards by the end of this year, 'we shall see a serious disenchantment with the IMO process and a proliferation of local regulations, led in all probability by the EU and the US'.
National and regional regulation has already begun in America and Europe. For example, the US House of Representatives approved legislation in March to allow the coastguard and Environmental Protection Agency to enforce emission limits on thousands of domestic and foreign-flagged ships that enter US waters each year.
If the IMO fails to come up with credible and enforceable global standards, sea-based transport will be saddled with a patchwork quilt of regulation. This will slow shipping and maritime trade, and increase its cost.
Michael Richardson is visiting senior research fellow at the Institute of Southeast Asian Studies in Singapore. This is a personal comment. firstname.lastname@example.org