Holocene Climate and Environmental Changes in the Alps

Abstract In mountain regions such as the Alps, various and partly typical climate archives can be found, including glaciers, tree-rings, and lake sediments. The associated climate proxies can be analysed and dated with different temporal resolutions ranging from sub-annual to multi-centennial in order to reconstruct past climate variability. With a focus on the medium- to long-term evolution of the climate during the Holocene, the climate changes in the Alps can be understood as a regional reflection of hemispheric processes, particularly those in the North Atlantic region. The onset of the Holocene was characterised by an abrupt warming around 11.7 ka, followed by a further increase in temperature, reaching levels similar to those of the late Holocene shortly after 11 ka and those of the Holocene Thermal Maximum around 10 ka. Finally, temperatures started to decline from the mid-Holocene until the pre-industrial period with the Little Ice Age as the coolest multi-centennial period since about 10 ka. This Holocene temperature trend largely reflects the evolution in summer insolation in the Northern Hemisphere. In contrast to temperature, no long-term trends in precipitation variability in the greater Alpine region have been identified for the last about 10 millennia. The climate evolution during the Holocene is the background to human activities and settlements in the Alps. Human presence at high-elevation sites can be documented from around 11 ka onwards. Yet there is no obvious association between mid- and late Holocene climate variability and settlement development.