A review of snow in Britain: the historical picture and future projections

摘要

Climate change is likely to have a significant effect on snow globally, with most effect where current winter temperatures are close to 0°C, including parts of upland Britain. There is evidence of decreasing trends in observations of snowfall and lying snow in Britain, and climate projections suggest a continuation of this trend. Although river flows in Britain are generally dominated by rainfall rather than snowmelt, some upland catchments have a significant snowmelt contribution. There is evidence of changes in observed and projected river flows in some catchments in Britain, linked to changes in snow, but it can be difficult to distinguish the effects of snow changes from those of other concurrent changes (climatic and non-climatic). Flow regime changes in catchments with widespread and prolonged winter snow cover usually involve increases in winter flow and decreases in spring flow, but the effect on catchments with more transient snow cover is less clear, as is the effect on high flows and water quality. Snow can also affect a number of other factors of socio-economic or environmental importance (e.g. transport and farming). There is some evidence that disruption due to snow may be less frequent in the future, but disruption from other types of weather events may increase. The impacts of snow tend to be worse in areas where events occur less frequently, due to unpreparedness, so there is a need to guard against complacency when it comes to future snow events in Britain, which can still be expected despite a likely reduction in frequency. Further modelling of the potential impacts of climate change, including modelling the influence of snow changes as well as other climatic and non-climatic changes, would aid adaptation and encourage mitigation.