Centennial climate variability in the British Isles during the mid–late Holocene

Abstract

Multi-millennial climate changes were relatively minor over the mid-late Holocene in the British Isles, because orbitally forced insolation changes were smaller than those at higher latitudes. Centennial climate variability is thus likely to have exerted a greater influence on the environment and human society of the region. Proxy climate records from the British Isles covering the last 4500 years are assembled and re-evaluated with the aim of identifying centennial climate variability reflected by multi-proxy indicators. The proxies include bog oak populations, peatland surface wetness, flooding episodes from fluvial deposits, speleothem band width and oxygen isotopes, chironomids from lake sediments and sand and dune deposition. Most proxies reflect water balance rather than temperature alone, and records predominantly reflect warm season climate. A series of twelve key periods of enhanced precipitation-evaporation (P-E) are identified by their presence in two or more proxy records.Variability in P-E is much greater than that shown by temperature proxies and there is no necessary association between warm/cool and dry/wet periods. Although the data for temperature are less robust than those for P-E, a series of key temperature changes are

High-magnitude flooding across Britain since AD 1750

“…5) generated for Britain corresponds well to events/periods recorded elsewhere within the literature containing significant flood events, whereas other proxy series fail to show clear relationships for the study period, e.g. the peat wetness record (Charman, 2010). In the context of the long historical flood series available for mainland Europe, flooding appears to be synchronous and asynchronous during different phases in comparison to the British series.…”

Detecting climatic signals in an anthropogenically disturbed catchment: The late-Holocene record from the Petit Lac d’Annecy, French Alps

“…BSW records throughout NW Europe change at similar times and seem to be controlled by a common climatic forcing, namely the North Atlantic Multidecadal Oscillation (NAO) (Barber and Charman, 2003;Barber, 2006;Hughes et al, 2006;Sutton and Hodson, 2005;Charman et al, 2010). The regional nature of this climate forcing means that it is reasonable for us to use it as …”

“…The age-depth model (black line) is a cubic polynomial fit to the 14C, 210Pb and magnetic chronological markers (with individual Agreement indices greater than 60%), also showing the 90-95 prediction error (red lines). 138x134mm (300 x 300 DPI) (Panels H -N) are presented, sub-divided into 7 historical periods following Crook et al, 2002;2010. Selected pollen profiles are used to reconstruct past land cover change including forest cover (Total Arboreal pollen excluding Alnus (AP%)) and agricultural activity (e.g.…”

Evaluating long‐term regional climate variability in the maritime region of the St. Lawrence North Shore (eastern Canada) using a multi‐site comparison of peat‐based paleohydrological records

“…The Holocene climatic conditions may have differed slightly between the St. Lawrence North Shore and northern Quebec where most proxy climate data are available. Therefore, further proxy climate data will be required to evaluate more accurately the relationship between Holocene climate variability and BSW in the maritime regions of eastern Canada. Shifts in BSW have commonly been interpreted as changes from cool and/or wet to warm and/or dry climate in midlatitude Europe Barber et al, 2003;Barber and Langdon, 2007;Charman, 2010). Previous studies suggested that water table records in peat bogs primarily reflect changes in summer water deficit and that moisture deficit in oceanic peatlands is mainly related to precipitation (Charman et al, 2004;Charman, 2007).…”