Future Projections of Trans-Arctic Shipping Potential and Variability

Abstract:

As the Arctic Ocean transitions towards a seasonally ice-free state, efforts to predict new connections between the Arctic and the global economy are underway. In particular, record lows in September sea ice extent from 2007-2013 have recast Arctic shipping routes as emerging international seaways for export of resources and as potential alternative pathways for global trade. While ensemble-averaged output from sea ice models suggest significant increases in vessel accessibility in September by midcentury (Smith & Stephenson, 2013), the seasonal length and variability of trans-Arctic shipping is not well understood. In addition, differences in ice extent due to inter-model variability reveal significant uncertainties in the magnitude and location of future vessel access. Here we present several scenarios of 21^st-century trans-Arctic shipping as driven by sea ice output from CMIP5 models. Optimal vessel transits from North America and Europe to the Bering Strait are estimated for two periods representing present-day (2006-2015) and midcentury (2040-2059) conditions under two forcing scenarios (RCP 4.5/8.5), assuming Polar Class 6 (PC6) and open-water vessels (OW) with medium and no ice-breaking capability, respectively. Results illustrate a range of potential futures for shipping in the Arctic owing to differences in model choice, vessel capability, and climate forcing. Inter-model differences reveal the importance of model choice in devising projections for strategic planning by governments, environmental agencies, and the global maritime industry.