Impact of Climate Change and Extreme Waves on Tanker Design

Abstract

Global warming and extreme weather events reported in the last years have attracted a lot of attention not only in academia and media but also in the shipping industry. Three important questions have been in focus: will occurrence of extreme weather events increase in the future, which geographical locations will be most affected, and to what degree will climate change affect future ship traffic and design of ship structures. Observed and projected changes in wave conditions are expected to have the largest effect on ship design and operations in comparison to other environmental phenomena. The present study briefly summarizes recent investigations addressing changes of significant wave height in the North Atlantic, including the last findings of IPCC (Intergovernmental Panel on Climate Change), and discusses how these changes can be included in environmental description used for ship design. It is also interesting to notice that climate changes resulting in some ocean regions in increase of storm activity (intensity, duration and fetch) and changes of storm tracks may result in secondary effects such as increased frequency of occurrence of abnormal waves, also called rogue or freak waves. This study shows how the scientific findings on climate change and rogue waves can be incorporated in the risk-based approach used in current design practice of tankers, and ships structures in general. Further, it demonstrates the effect of climate change and rogue waves on tanker design, particularly on the safety level of current design practice. Finally, the present paper discusses how structural design of ships can be upgraded to account for climate change and rogue waves but economic consequences do not need to be significant.