Improved Projections of 21st Century Trans-Arctic Shipping

Abstract:

Climate models unanimously project a decline in the extent and thickness of Arctic sea ice as the climate warms, but at differing rates. Projecting the timing of an ice-free Arctic is a topic that has received considerable scientific and public attention. An ice-free Arctic opens up the potential for shorter global trade routes through the Arctic Ocean and there has already been a sharp increase in the number of transits along Russia’s Northern Sea Route with escorts from nuclear powered icebreakers.

Here we present results on the future of trans-Arctic shipping using bias corrected sea ice thickness projections, utilising the CMIP5 multi-model ensemble and considering multiple emission scenarios. We find that for ‘Open Water’ vessels (normal ocean going vessels that possess no specific ice strengthening), unaided trans-Arctic shipping is likely to become feasible in the next couple of decades. We find that the North West Passage will open approximately a decade later than the Northern Sea Route. Initially however, both routes exhibit marked inter-annual variability in accessibility which we quantify. The hypothesised trans-polar sea route through international waters via the North Pole will start to become navigable by 2050. Towards the latter period of the 21^st century, normal ocean going vessels will be able to transit their choice of any of these routes for at least six months of any given year under the RCP 8.5 high future emissions scenario and four months for the lower RCP 4.5 emissions scenario. These findings suggest that further increases in global temperature could transform the Arctic into a global transport hub.