The Impact of 21st Century Climate Change on Ski Season Length for Western North American Ski Resorts Under RCP4.5 and RCP8.5 Emission Scenarios

Several studies have suggested that the winter recreational activities of skiing and snowboarding will be severely impacted by changes in temperature and precipitation driven by future human caused climate change. Climate change should cause the length of the ski season to shorten, mainly controlled by warming temperatures. This research models the changes in ski season length for 154 ski resorts in Western North America to the year 2085. Using high quality monthly mean temperature data from ClimateNA and ClimateBC spatial interpolated climate databases, we were able to construct curves of average daily mean temperature change for a historical baseline period and the year 2085 for RCP4.5 (best-case) and RCP8.5 (worst-case) emission scenarios for the mid-elevation of each ski resort. For the baseline period 1971-2000, monthly averages were determined from the 30 years of data. A best-fit curve approximating the day-to-day change in mean temperature was then determined from the monthly averages using polynomial regression. The daily mean temperature curves for 2085 were constructed with average monthly data from 15 different IPCC AR5 climate models, for each of the two emission scenarios. The start and end date of the ski season was determined by a threshold daily temperature of 0^oC. Results show a clear shift in distribution of length of ski season. Under the baseline 1971-2000 6% of resorts have season length under 90 days, under RCP4.5 36% of resorts have season length under 90 days with 13% having no definitive ski season and under RCP8.5 66% of resorts have season length under 90 days with 31% having no definitive ski season. Mapping the change in ski length, coastal resorts (within 400km of the Pacific Coast) experience higher precipitation and warmer temperatures than the continental resorts showing a clear effect of geography in the difference in length of ski season. 80% of coastal resorts and 2% of continental resorts under RCP4.5 and 95% of coastal resorts and 7% of continental resorts under RCP8.5 have a ski season length of zero days. This research is being conducted with hopes that it can assist some of the winter sport groups in their lobbying efforts to help combat climate change as well as provide a basis for adaptation and mitigation techniques.