Projecting climate change impacts on mountain snow cover in central Scotland from historical patterns

Cumulative days of seasonal snow cover at Ben Lawers National Nature Reserve, a mountain site in Scotland, are related to altitude, temperature, and precipitation using a 45-year record from a nearby climate station. Multiple linear regression is used to model interannual variation in snow cover duration as a function of winter mean daily temperature and monthly precipitation. Snow cover duration is closely linked to temperature, while precipitation contributes a positive effect among winters of similar temperature mode. Snow cover duration at mid to upper altitudes (600–900 m) responds most strongly to variation in mean daily temperature. A 1 °C rise in temperature at the station corresponds to a 15-day reduction in snow cover at 130 m and a 33-day reduction at 750 m. The empirical relationship is applied to climate change scenarios from the HadRM3 regional climate model. Under a ‘low’ greenhouse gas emissions scenario, snow cover in the 2050s is projected to be reduced by 93% at 130 m, 43% at 600 m and 21% at 1060 m, while under a ‘high’ emissions scenario these reductions are projected to be 100%, 68%, and 32%, respectively. The potential impact of snow cover reduction on snow-dependent vegetation is modeled. The results suggest a future decline in climax vegetation of international conservation importance.