Emission reduction in international shipping-the hidden side effects

In order to curb the trend toward global warming, many technical, operational, and policy options have been proposed to help reduce the emissions from international shipping-the carrier for 80% of the world's trade. However, these options might not only reduce emissions from shipping activities, but could also have a ripple effect on the whole supply chain of traded goods, as well as on those serving shipping activities. These effects could have both positive and negative impacts, not only on emission reduction, but also on world trade, economic efficiency, and the local environment. While most studies have examined the feasibility of the various options and their potential contribution to emission reduction, their secondary impacts have not been studied. However, failing to take them into account could very well obstruct the implementation of the options. Through a review of existing studies, this article aims to identify and explain some of these previously unexamined secondary effects that are associated with emission reduction in international shipping, point out the problems that will arise if they are ignored, and provide a basis for further detailed research in this area.