Sensitivity of Snow at Western US Ski Resorts to Climate Change

ABSTRACT The sensitivity of winter recreation to climate change, especially to warming, is widely recognized but few studies report quantitatively on the observed effects of climate change on ski resorts, in part because consistent and available data directly from ski resorts is scarce. Augmenting strictly modelling‐based studies, we use both numerical modelling and observation‐based estimates of sensitivity in snow depth (HS) and snow water equivalent (SWE) to temperature and precipitation using data from nearby SNOTEL (snow telemetry) and snow course sites for 40 ski resorts in Washington, Idaho, Oregon and California during the ski season. Multiple regression on climate variables then permits statistical projections of future snow depth from projected changes in temperature and precipitation with 20 future climate scenarios (10 global climate models and 2 emissions scenarios, RCP4.5 and RCP8.5). We also use projected future SWE from a hydrology model with climate input from the same 20 climate scenarios. The two methods produce substantially different projected changes at individual resorts but in aggregate the distributions are similar, leading to these broad conclusions: While many resorts indeed face substantial declines in ski‐season snow depth, many of those in the inland Northwest and a few at high elevation are likely to be minimally affected. Mitigating factors include (a) projected increases in winter precipitation over the Rockies that partly offset the effects of warming; (b) low temperature sensitivity at those locations and over high altitudes; (c) lower observed declines and temperature sensitivity for snow in winter compared with spring; and (d) many ski resorts are located in areas of high snowfall and/or span a considerable range of elevations.