Fig. 6.

Relationship between (a) advance in breakup or (b) delay in freeze dates and the proportion of possible ice crossings. Ice crossings by migratory caribou were observed between 2007 and 2014, whereas changes in breakup or freeze dates (from 1 to 30 days) represent potential consequences of warming air temperatures in the Arctic during the next 25–50 years (2041–2070 horizon). Projections of future freeze and breakup dates are taken from (i) Brown and Duguay [19] in red, (ii) Dibike et al. [50] in blue, (iii) Shuter et al. [51] in orange, and (iv) Brammer et al. [52] in black