The Impact of Climate Change on European Lakes

Abstract

The above quotation, taken from a thirteenth century Welsh manuscript (Jones and Jarman, 1982), elegantly expresses the essence of this book. In a few words, the poet encapsulates the practical consequences of an extreme climatic event and describes its impact on the quality of water in a river and the physical characteristics of a lake. This poem was probably composed at the beginning of the thirteenth century when Britain experienced some very severe winters (Ogilvie and Farmer, 1997). Today, severe winters are rare but we are becoming increasingly concerned about the impact of mild winters and warm summers on the quality of the water in our lakes and rivers. The ecological status of many lakes in Europe has changed dramatically over the last 20 years. Many of these changes are the result of anthropogenic influences in the catchment but some are also driven by changes in the regional climate (George, 2002; Blenckner and Chen, 2003; Straile et al., 2003). In Northern European lakes, the most important climatic effects are those associated with the extension in the duration of the ice-free period (Weyhenmeyer et al.,; Weyhenmeyer et al., 1999). In Western European lakes, the most important impacts are those connected with the increased winter rainfall (George et al., 2004) and the changing frequency of calm summer days (George et al., 2007).