Abstract
In April 2018 at the 72nd session of IMO’s Marine Environment Protection Committee, a GHG strategy consistent with the Paris Agreement temperature goals was adopted. The main target set was to reduce absolute GHG emissions from shipping in 2050 by 50% compared to 2008. To reduce GHG emissions there are five main technical and operational measures: hull design; power and propulsion; alternative fuels; alternative energy sources; and operations. In this paper we focus on the potential reductions through hull design, i.e. length and hull shapes in relation to speed and sea states. Our findings indicate that moderate increases of length and reduction of block to enable better hull shapes give 10 – 20 % reduction of annual fuel consumption and hence emissions for a low or even negative abatement cost. Achieving these reductions will require that national and international authorities stop penalizing energy efficient ships with increased length compared to standard tonnage through higher port and fairway fees; pilotage rules; and artificial sailing restrictions.