A multi-proxy perspective on millennium-long climate variability in the Southern Pyrenees
Abstract. A review of selected, well-dated, multiproxy paleoclimatic records (lacustrine, dendrochronological, geomorphological) characterizes the main environmental changes occurred in the Southern Pyrenees during the last millennium. Warmer and relatively arid conditions prevailed during the Medieval Climate Anomaly (MCA, <1300 AD), with a significant development of xerophytes and Mediterranean vegetation and limited deciduous tree formations (mesophytes). The Little Ice Age (LIA, 1300–1800 AD) was generally colder and moister, with an expansion of deciduous taxa and cold-adapted mountainous conifers. Two major phases occurred within this period: (i) a transition MCA-LIA, characterized by fluctuating, moist conditions and relatively cold temperatures (ca. 1300 and 1600 AD); – (ii) a second period, characterized by coldest conditions and higher humidity, coinciding with maximum (recent) glacier advances (ca. 1600–1850 AD). After the LIA a warming and more arid phase started coinciding with glacier retreat, and interrupted by a short-living cooling episode during the late 19th to early 20th centuries. Some records suggest a response to solar activity with colder and slightly moister conditions during solar minima. Centennial-scale hydrological fluctuations are in phase with reconstructions of NAO variability, which appears to be the main forcing for humidity in the region during the last millennium.