A Regional Approach to the Medieval Warm Period and the Little Ice Age

摘要: In order to gain knowledge of the temperature variability prior establishment a widespread network instrumental measurements c. AD 1850, we have draw information from proxy data sensitive variations. Such can be extracted various natural recorders climate variability, such as corals, fossil pollen, ice-cores, lake and marine sediments, speleothems, tree-ring width density, well historical records (for review, see IPCC 2007; Jones et al. 2009; NRC 2006). Considerable effort has been made during last decade reconstruct global or northern hemispheric temperatures for past 1000 2000 years in place observed 20th century warming long-term perspective (e.g., Briffa, 2000; Cook al., 2004; Crowley Lowery, D’Arrigo, 2006; Esper 2002; Hegerl 1998; Mann, Juckes Ljungqvist, 2010; Loehle, Mann 1999; 2008; Jones, 2003; Moberg 2005; Osborn Less put into investigating key question what extent earlier warm periods homogeneous timing amplitude different geographical regions present warming. It suggested that late-Holocene variations, Medieval Warm Period (MWP) Little Ice Age (LIA), restricted circum-North Atlantic region (including Europe) not occurred synchronic time with cold respectively other (Hughes Diaz, 1994; 2003). This view has, however, increasingly challenged through ever growing amount evidence (or at least hemispheric) MWP LIA become available (see, example, Frank, 2009, Wanner 2008). A main obstacle large-scale reconstructions continues limited unevenly distributed number quantitative palaeotemperature extending back millennium more. The rendered it impossible very selective choice data. Palaeotemperature used reconstruction should preferably accurately dated, high sample resolution correlation local record calibration period (see discussion 2009). long 1