EU Governments have, in recent years imposed stringent restrictions on emissions of NOx from a wide range of industrial and commercial activities including road vehicle transport, but relatively little has been done to reduce emissions from ships which now account for more than a quarter of total emissions of nitrogen oxides in Europe.
Under current growth trends, emissions from international shipping in European sea areas are projected to increase by nearly 40 per cent between 2000 and 2020. If no additional abatement measures are taken, by 2020 the emissions from shipping around Europe are expected to equal or even surpass the total from all land-based sources in the 27 EU member states combined. As a consequence, the number of annual deaths from ozone and PM exposure in Europe is likely to stay high.
NOx emission standards for international shipping are set by the International Maritime Organisation (IMO). New regulations were introduced by the IMO in 2008 which strengthen somewhat the NOx requirements worldwide for all new ships built after January 01, 2011.
In addition, the IMO decided that in designated sea areas called Emission Control Areas (ECAs), significantly more stringent rules will apply to all new ships built after 01 January 2016 when sailing in these ECAs. Affected ships will have to reduce emissions of NOx by about 80 per cent from the current limit values.
A problem in the context of the new IMO NOx standards is that they only apply to new ships. Ships tend to have a life of 25–35 years before being scrapped so the turnover of the fleet is slow. In addition it is feared that the new regulation could be evaded by operators only deploying older ships in ECAs.
Thus in order to not only limit the growth in ships’ NOx emissions, but actually to reduce them, there is a need to cut emissions from existing vessels and to speed up the introduction of efficient NOx abatement technologies in new ships built before 2016.