Shipping is considered to be a significant source of global air pollution, both for conventional pollutants and greenhouse gases. Sulphur and black carbon, also called soot, are released in the air in large quantities because large (container and cruise) ships use heavy bunker oil. This is oil from the waste well of the oil industry, the cheapest and dirtiest thing you can get. Seventeen containerships emit as much sulfur as all the cars on the planet in one year. And one cruise ship emits a day as much soot as one million cars.
Shipping itself is sometimes referred to as "the most unregulated, secretive and polluting industries in the world." There is a perception that cargo transport by ship is low in air pollutants, because for equal weight and distance it is the most efficient transport method. This is particularly true in comparison to air freight, however, because sea shipment accounts for far more annual tonnage and the distances are often large, shipping's emissions are globally substantial.
Early Regulatory Efforts
The big problem is that the seas and oceans belongs to everyone, and that regulation of vessel-source pollution, both national and international, is and remains inadequate. One of the most important concepts employed internationally is that of controlled discharges within ocean zones. This concept can be traced back to the first pollution control measure taken in history to be introduced beyond territorial limits in areas then considered to be high seas: at a conference convened in Washington DC in June 1926 the United Kingdom and the United States were able to persuade other states to adopt pollution control zones of up to 50 nautical miles from shore. Within these zones, which States could declare at their discretion, ship discharges beyond 500 parts per million (ppm) of oil to water were prohibited.
But international law remained unaltered: flag states retained jurisdiction over their vessels, even within these prohibition zones. As such, this concession to flag state jurisdiction was the major flaw of the zonal system, because flag states, then and now, lack the incentive to control the polluting activities of their flag vessels in other states’ waters. And on the other hand, coastal states did not posses enforcement authority over foreign vessels outside the three-mile limit. Recognising these shortcomings, the United States proposed to introduce even stricter requirements, an ocean-wide prohibition on discharges beyond certain concentration, the so-called ‘total prohibition’ measure. Despite its merits, this proposal was ultimately defeated by maritime powers which objected to the costs of port reception facilities. The draft convention produced by the 1926 Washington Conference never came to formally adopted. Nevertheless, the genesis of the ‘ppm’ discharge standard and the ‘prohibition zone’ concept were widely prescribed in later vessel-source pollution related conventions.
Air Pollution from Ships
The protection of the marine environment has become one of the most important ecological issues of modern times. In the decades after the 1926 Washington Conference, international, regional and national regulation over shipping matters, such as vessel-source pollution, have grown considerable. Despite the proliferation over shipping, many international instruments which prescribe pollution control measures are still not effectively enforced and adhered to. The most obvious weakness of the regulatory system appears to be its failure to ensure effective enforcement and compliance with the relevant rules and standards. Consequently, many low-cost, ‘sub-standard’ ships run by irresponsible operators still ply the oceans today.
In the realm of air pollution, certain actors in the shipping industry, such as the oil companies, have been able to influence the effectiveness of international rules and obligations. Global concern has arisen over the effects of ozone-depleting substances (ODS) and greenhouse gases such as carbon dioxide. Even before these issues had captured international attention, acid rain was already raising concern in the early eighties. Questions arose over the contribution of shipping to this problem, even though it was clear that land-based sources contributed to the bulk of such air pollution. At the so-called North Sea Conferences held in 1987, Norway, for the first time, raised the issue of regulating the content of sulphur, the major cause of acid rain, in heavy bunker oil. The deliberations at these conferences, led the issue being raised at the International Maritime Organization. The European parties to the 1979 UN-ECE Convention on Longe-Range Transboundary Air Pollution also supported this issue.
International Maritime Organization
At IMO, member states acknowledged that the most effective solution was to ensure the use of low-sulphur marine bunker fuels. It was thus proposed that the new annex to the International Convention for the Prevention of Pollution from Ships (MARPOL 73/78) be adopted to restrict or ‘cap’ the content of sulphur. At that time, the prevailing global standard for marine fuel oil was a maximum of 5 % sulphur content. Member states proposed that the IMO adopt a substantially lower cap, with Western European states favouring a global solution. However, the initial proposals encountered substantial resistance from the shipping and oil industries as well as the developing oil-producing countries. The economic consequences of a sulphur cap were high (costs), and it would severely affect oil-producing states whose crude oil resources contained high sulphur levels.
The discussions went on. The oil industry decided, largely to stave off demands for a strict global cap, to support the adoption of stringent standards in special areas where the air pollution problem was demonstrably more acute. The shipping industry and the major flag states were less happy with the ‘special area’ concept. Their ships would have to be burdened with storing different grades of fuel, causing a considerable reduction of their cargo capacity and the risk of engine breakdown. Environmental activists als rallied strongly against this idea, but mainly for other reasons.
Despite these reservations, global consensus was reached on the need for special areas and a 1.5 % cap within such areas. But with the acceptance of the ‘special area’ concept, the opponents of a global cap argued that no longer a cap outside these areas was needed: the standard here, should remain 5 %. The debate over the cap was carried into 1997 Conference of Parties to MARPOL 73/78. After lengthy discussions, agreement was achieved on a compromise global cap of 4.5 % of sulphur in marine bunker fuels. This agreement was laid out in the new MARPOL Annex VI on the Regulations for the Prevention of Air Pollution from Ships. The Annex, also limits other vessel-source air pollutants, such as nitrous oxides (NOx), and prohibits deliberate emissions of ozone depleting substances. It regulates shipboard incineration, and the emissions of volatile organic compounds from tankers. MARPOL Annex VI entered into force on 19 May 2005.
Revised MARPOL Annex VI
Following entry into force of MARPOL Annex VI in 2005, the Marine Environment Protection Committee (MEPC) agreed to revise MARPOL Annex VI with the aim of significantly strengthening the emission limits in light of technological improvements and implementation experience. The main changes to MARPOL Annex VI are a progressive reduction globally in emissions of SOx, NOx and particulate matter and the introduction of emission control areas (ECAs) to reduce emissions of those air pollutants further in designated sea areas. Under the revised MARPOL Annex VI, the global sulphur cap will be reduced in the long term to 0.50%, effective from 1 January 2020. Progressive reductions in NOx emissions are also included as well as several revisions to the regulations for ozone-depleting substances, volatile organic compounds, shipboard incineration, reception facilities and fuel oil quality.
According to the International Maritime Organization, these revised measures are expected to have a significant beneficial impact on the atmospheric environment and on human health, particularly for those people living in port cities and coastal communities. Environmentalists on the other hand, are not so sure. One of them stated: "One thing has become clear to me: these industries, we can not leave it in the expectation that they are going to solve the climate problem themselves without supervision."
- Hildreth, R. and A. Torbitt, “International Treaties and U.S. Laws as Tools to regulate the Greenhouse Gas Emissions from Ships and Ports”, in: J.M. Van Dyke, S.P. Broder, S. Lee and J.-H. Paik, Governing Ocean Resources: New Challenges and Emerging Regimes: A Tribute to Judge Choon-Ho Park, Leiden; Boston, Martinus Nijhoff Publishers, 2013, pp. 461-488.
- Hinrichs Oyarce, X., “Greenhouse Gas Emissions from Ships and Technology Transfer”, A. Kirchner and I. Kirchner-Freis, Green Innovations and IPR Management, Alphen aan den Rijn, Kluwer Law International, 2013, pp. 215-230.
- Karim, M.S. and F. Deane, “Proposed MBMs for Reduction of Greenhouse Gas Emissions from International Shipping and the WTO Rules”, Lloyd's Maritime and Commercial Law Quarterly, (2014), No. 3, pp. 370-392.
- MARPOL Annex VI and NTC 2008: with Guidelines for Implementation, London, International Maritime Organization, 2013.
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- Tan, A.K.-J., Vessel-Source Marine Pollution: The Law and Politics of International Regulation, Cambridge, Cambridge University Press, 2006.
- Zhu, L., H. Jessen and M. Zhang, “The Way Forward for Hong Kong to Combat Vessel Source Emissions in the Pearl River Data Region”, Ocean Development and International Law, 46 (2015), No. 2, pp. 208-224.