Introduction

The impacts of climate change have been particularly profound in Arctic regions (ACIA, 2005; IPCC, 2007), with changes in the sea ice standing out (Kerr, 2007). For the Arctic as a whole, ice thickness and extent are decreasing, the ocean is freezing up later in the year and breaking up earlier, and the ice-free open water period is extending (Holland et al., 2006; Overland and Wang, 2007). Similar trends have been documented in the Canadian Arctic (Barber and Hanesiak, 2004; Barber and Iacozza, 2004; Nickels et al., 2006; Furgal and Prowse, 2008; Laidler and Ikummaq, 2008). Anomalous ice conditions are concentrated in recent years of the record, particularly 2002–2007 (Stroeve et al., 2007). Sea ice change is occurring in the context of other changes in the Arctic, and has been attributed to greenhouse gas emissions (IPCC, 2007).

Changing sea ice conditions have already had negative impacts on the livelihoods of the Arctic's Inuit population, many of whom rely on the frozen ocean surface for seasonal transportation between communities and as a platform for culturally important hunting activities (Correll, 2006; Nickels et al., 2006; Ford, 2008a; Ford et al., 2008b). Climate models predict sea ice change to continue into the foreseeable future (IPCC, 2007), with recent research ranking sea ice as the global system at greatest threat to crossing a ‘tipping point’ with climate change (Lenton et al., 2008).