Influence of climate model variability on projected Arctic shipping futures

Abstract

Though climate models exhibit broadly similar agreement on key long-term trends, they have significant temporal and spatial differences due to intermodel variability. Such variability should be considered when using climate models to project the future marine Arctic. Here we present multiple scenarios of 21st-century Arctic marine access as driven by sea ice output from 10 CMIP5 models known to represent well the historical trend and climatology of Arctic sea ice. Optimal vessel transits from North America and Europe to the Bering Strait are estimated for two periods representing early-century (2011-2035) and mid-century (2036-2060) conditions under two forcing scenarios (RCP 4.5/8.5), assuming Polar Class 6 and open-water vessels with medium and no ice-breaking capability, respectively. Results illustrate that projected shipping viability of the Northern Sea Route (NSR) and Northwest Passage (NWP) depends critically on model choice. The eastern Arctic will remain the most reliably accessible marine space for trans-Arctic shipping by mid-century, while outcomes for the NWP are particularly model-dependent. Omitting three models (GFDL-CM3, MIROC-ESM-CHEM, and MPI-ESM-MR), our results would indicate minimal NWP potential even for routes from North America. Furthermore, the relative importance of the NSR will diminish over time as the number of viable central Arctic routes increases gradually toward mid-century. Compared to vessel class, climate forcing plays a minor role. These findings reveal the importance of model choice in devising projections for strategic planning by governments, environmental agencies, and the global maritime industry.

Late summer distribution and abundance of ice-associated whales in the Norwegian High Arctic

“…The Arctic region is changing most rapidly, with sea ice losses being one of the most visible climate-induced changes to date (Walsh 2008, Onarheim et al 2014. The Svalbard Archipelago in Norway is an Arctic 'hot spot', which is experiencing anomalously high losses of sea ice in terms of overall extent, thickness, proportion of multiyear ice and seasonal duration of sea ice, as well as large increases in both air and water temperatures (Pavlov et al 2013, Nordli et al 2014, Laidre et al 2015, Stephenson & Smith 2015.…”

Implications of climate change for shipping: Opening the Arctic seas

“…In a similar study to Melia et al (), Stephenson and Smith () projected optimal Arctic routes between two North Atlantic ports. They obtained ice projections from a subset of CMIP5 models, selected via model weighting, forced under RCP 4.5 and 8.5; they then applied these ice projections to a transport navigability model based on the Arctic Ice Regime Shipping System.…”

“…They obtained ice projections from a subset of CMIP5 models, selected via model weighting, forced under RCP 4.5 and 8.5; they then applied these ice projections to a transport navigability model based on the Arctic Ice Regime Shipping System. Their results forecast the density of optimal routes in the Arctic for both OW and PC6 vessels traveling between the two North Atlantic ports in the years 2011–2035 and 2036–2060 (Figure ) (Stephenson & Smith, ). These results suggest that even under RCP 4.5 emissions, OW vessels will be able to access the TSR by 2036–2060 (Stephenson & Smith, ).…”

Climatic Responses to Future Trans‐Arctic Shipping

“…In particular, the prospect of trans‐Arctic shipping is supported by shipping simulations that show robust increases in trans‐Arctic access by midcentury under multimodel climate projections (Aksenov et al, 2017; Khon et al, 2017; Melia et al, 2016; Stephenson & Smith, 2015). Of particular geopolitical interest is the so‐called trans‐polar route over the North Pole, the shortest theoretical crossing between the North Atlantic and the Bering Strait that circumvents central Arctic state territorial waters and Exclusive Economic Zones (Clarke‐Sather et al, 2017).…”