by MICHAEL PIDWIRNY, KALIM BAHBAHANI and SHANE PEDERSEN
By the end of the 21st century, the Intergovernmental Panel on Climate Change (IPCC) predicts that the continued emission of greenhouse gases by human activity will significantly increase surface air temperatures and change patterns of precipitation on our planet at local, regional, and global spatial scales. Being able to forecast how climate change will influence socio-economic systems is important to assess potential impact to humans. Understanding this impact will also allow for the development of effective adaptation and mitigation strategies to minimize the negative effects of climate change.
Analysis of the climatic impacts associated with human caused climate change at alpine ski resorts is quite straightforward using recently developed techniques which mathematically interpolate measurements from weather stations to other nearby locations. The research presented here uses spatially interpolated climate data which is generated by the software databases ClimateBC and ClimateWNA (Wang et al., 2012). These climate software databases can produce data for the historical period 1901-2015 and future climate forecasts for the 21st century generated by climate simulation models used in the 5th Assessment Report of the IPCC.
Alpine ski resorts in western Canada receive considerable year-to-year variation in surface air temperature and snowfall during the winter season (December, January, and February). This variability can sometimes hide trends when the data record is short. Figure 1 illustrates the variation in winter mean temperature for Cypress Ski Resort located just north of Vancouver, British Columbia for the period 1901 to 2015. Over this 115-year period, we can observe an obvious warming trend for winter mean temperature of about 1.5° C. It is important to note that the winter mean temperature of 2015 was warm enough to cause this resort to close down for most of that ski season.
Trying to forecast how future climate change during the 21st century will affect Cypress Ski Resort and other resorts in western Canada can also be accomplished by using ClimateBC and ClimateWNA. However, the exact nature of this climate change is somewhat uncertain because it will depend on our future efforts to reduce greenhouse gas emissions into the atmosphere. Table 1 describes the estimated future atmospheric concentrations of the main greenhouse gases under a best-case (called RCP4.5) and a worst-case (called RCP8.5) scenario available in ClimateBC and ClimateWNA. The best-case scenario correlates to a warming of the Earth’s surface globally of about 2.0° C relative to pre-industrial greenhouse gas levels. Many climate scientists believe this scenario can be achieved if nations act soon to reduce emissions primarily through reforestation, other carbon capture techniques, increased energy-use efficiency and switching to renewable based energy generation. The worst-case scenario corresponds to a future pathway where greenhouse gas emissions continue to increase exponentially and average global temperature becomes between 3.0 to 5.0° C warmer by 2100.
Figures 2 and 3 describe historical and future forecasted changes in winter mean temperature and winter snowfall for twelve ski resorts along a longitudinal gradient from Vancouver Island to western Alberta. Table 2 describes location and elevation characteristics for these ski resorts. For winter mean temperature, we can see the selected resorts have already experienced between 1 to 2° C of warming from 1901-1930 to 1981-2010 (Figure 2).
Figure 2 also shows the anticipated future warming for the best-case and worst-case scenarios. Under the best-case scenario, the coastal ski resorts of Mt. Washington, Cypress, and Hemlock will probably become too warm to support skiing and snowboarding by the end of the 21st century. Whistler’s winter mean temperature will resemble the climate of 1981-2010 at Mt. Washington under this scenario. Under the worst-case scenario all of the coastal resorts will become much too warm to support winter recreation. The best-case scenario will make the winter mean temperatures of the interior ski resorts about 2.0 to 3.0° C warmer than what was experienced in 1981-2010. The worst-case scenario will add yet another 2.0° C.
Figure 3 suggests that the coastal ski resorts will face significant declines in winter snowfall in the future for both the best-case and worst-case scenarios. Most of the interior ski resorts will experience no change or slight increases in snowfall under the best-case scenario relative to the period 1981-2010. The worst-case scenario will cause less winter snowfall for Sun Peaks, Big White, Revelstoke and Whitewater interior ski resorts.
In conclusion, human caused climate change in the near future is predicted to result in warmer winter temperatures and changes in snowfall for the alpine ski resorts of western Canada. How detrimental these changes will be to the ski industry in western Canada depends on whether governments can implement meaningful reductions in the future emissions of greenhouse gases.
Wang, T., Hamann, A., Spittlehouse, D., and Murdock, T. N. 2012. ClimateWNA – High-resolution spatial climate data for western North America. Journal of Applied Meteorology and Climatology 61: 16-29.