THE world is waking up to a new acid rain threat. Sulphur pollution from
ships is increasing so dramatically that it could soon cancel out the
improvements made by cutting emissions from power stations and other land-based
sources.
The warning comes from Jan Thompson, Norwegian chairman of the executive body
that oversees the Convention on Long-range Transboundary Air Pollution, under
which governments have agreed to curb emissions of the gases which cause acid
rain. But the treaty only covers pollution from the land. In a letter to the
International Maritime Organization (IMO) in London, Thompson claims that the
contribution of shipping to worldwide sulphur emissions could more than double
by the year 2010 as merchant fleets expand. 鈥淔or certain sensitive areas,鈥� he
writes, 鈥渟hips might become one of the main contributors to the sulphur
deposition, and in some areas even the main contributor.鈥�
The soils and lakes of Norway are particularly vulnerable, and Norwegian
officials want urgent action. 鈥淭here have been many developments on land to
reduce sulphur emissions,鈥� says Lars Bru, a senior civil servant in the
Norwegian environment ministry. 鈥淯nless something is done for ships, their
relative contribution will increase drastically. The time to act is now.鈥�
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Over the next 15 years, pollution from factories and power stations in Europe
and North America should drop by up to 87 per cent from 1980 levels, as a result
of the transboundary treaty. But ships are free to burn cheap, dirty oils with a
high sulphur content, and shipping is already responsible for 7 per cent of
global sulphur emissions.
Next month, a meeting of the IMO鈥檚 Marine Environment Protection Committee
(MEPC) in London will attempt to close this loophole. It will discuss limiting
the sulphur content of the fuel used in ships鈥� boilers, and controlling maritime
emissions of nitrogen oxides.
Bin Okamura, deputy director of the MEPC, believes there is 鈥渁 good chance鈥�
that countries will agree to a sulphur limit in ships鈥� fuel oil of between 4.5
per cent and 5 per cent. But Bru fears that agreement on even this modest
proposal is unlikely, because some African and Asian countries believe that an
international sulphur cap will harm their domestic oil industries.
Alan Watson of the environmental group Friends of the Earth (FoE) is
unimpressed by the proposal. A sulphur limit of 5 per cent is 鈥渆xtremely high鈥�
he says, especially in the light of a forthcoming European Union directive which
from October will limit the sulphur content of diesel fuel for use on land to
0.05 per cent. In a proposal submitted to the MEPC for next month鈥檚 meeting, FoE
International claims that a sulphur cap of between 0.5 and 1 per cent for ships鈥�
fuel is probably necessary if environmentally sensitive areas are to be
protected from acid rain.
FoE International also points out that the current average sulphur content of
ships鈥� fuel is around 2.8 per cent. 鈥淭he apparent desire of a majority of IMO
states to set a global cap鈥hat is higher than the current average鈥an only
be understood in terms of oil industry interests,鈥� it argues.