Implications of projected climate change on winter road systems in Ontario's Far North, Canada

Understanding climate change impacts on winter road systems in Ontario's Far North is critical due to the high dependence on such seasonal corridors by local residences, particularly among remote First Nations communities. In recent years, a warmer climate has resulted in a shorter winter road season and an increase in unreliable road conditions, thus limiting access among remote communities. This study focused on examining the future freezing degree day (FDD) accumulations during the preconditioning period of the winter roads at five locations using the multi-model ensembles of general circulation models (GCMs) and regional climate models (RCMs), under the representative concentration pathway (RCP) scenarios. The Statistical DownScaling Model Decision Centric Version 5 (SDSM-DC) was applied to validate the baseline climate. The results from the CMIP5 showed that by mid-century, the trends of FDDs under RCP4.5 for Moosonee and Kapuskasing were projected to decrease below the lowest threshold with the mean FDDs at 376 and 363, respectively. Under RCP8.5, the mean FDDs for Lansdowne House and Red Lake were projected to be below the lowest threshold, at 356 and 305, respectively, by the end of the century. Results of the FDD threshold measure indicated that climate conditions would possibly be unfavorable during the winter road construction period by mid-century for Moosonee and Kapuskasing and for Lansdowne House and Red Lake by the end of the century. For Big Trout Lake, on the other hand, climate conditions are expected to remain favorable for the winter road construction through the end of 2100.