Is the impact from shipping different to this of land emitters?

The environmental impact depends on where the deposition of emissions takes place and not on the source. NOx and SOx emissions travel with the wind and can stay in the atmosphere over a long period of time until they are deposited to the earth thousands of kilometers away. The pattern is complex and emissions from sea affect the land or vice versa, for example NOx and SOx depositions at the North Sea (ref. Norwegian Meteorological Institute 2006, ISSN: 1890-0003).

So far NOx and SOx emissions from shipping do not exceed those from land but if a ‘business as usual’ attitude is maintained, this is bound to change by 2020 as shown in the RAINS model. It is therefore important to provide solutions before environmental impacts are irreversible, while the costs are moderate and while the conditions are favourable for shipping.