Changing temperature and rainfall gradients in the British Uplands

Climate change is likely to be experienced differently at higher elevations than in lowland areas. Observations of recent change can increase understanding of how changes will be realised. We examined changes in temperature lapse rates and rainfall gradients between pairs of stations, lowland and upland, across the UK. Seasonal and annual changes were investigated, because there may well be shorter-term changes which are not reflected in the overall annual average. Significant changes in both temperature and rainfall were observed, but the pattern of changes was spatially and seasonally variable across the UK. In general, temperature changes were stronger in winter than in summer, and minima rose more than maxima in the uplands, whereas the changes were similar between minima and maxima in the lowlands. Most ( but not all) upland stations showed significant increases in rainfall totals in winter that were greater than those experienced in the nearby lowlands. However, variations in seasonal trends of lapse rates and rainfall gradients are sufficiently large to warrant concern about existing climate change projections and the downscaling of regional and global climate models. Specifically, analysis at an annual time scale may mask important seasonal patterns. For countries where the data network is dominated by lowland stations but a significant proportion of the landscape is upland, this poses a problem for estimating temperature change over a large proportion of the landscape. Given the lack of a consistent pattern of changes, we advocate an extension of climate monitoring in the uplands in order to detail ongoing climate change in the different upland areas.