Northern Hemisphere temperature patterns in the last 12 centuries

2012/02/03 by Fredrik Charpentier Ljungqvist, Paul J. Krusic, Gudrun Brattström +1 · 2 citations
Earth and Planetary Sciences · Environmental Science · #Archaeology #Centennial #Climate change #Climate variability and models #Climatology #Dominance (genetics) #Geography #Geology #Geology and Paleoclimatology Research #Late 19th century #Little ice age #Northern Hemisphere #Oceanography #Period (music) #Physical geography #Proxy (statistics) #Southern Hemisphere #Tree-ring climate responses

paper · pdf · doi:10.5194/cp-8-227-2012

openalex publication_date 2012/02/03 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28

Abstract

Abstract. We analyse the spatio-temporal patterns of temperature variability over Northern Hemisphere land areas, on centennial time-scales, for the last 12 centuries using an unprecedentedly large network of temperature-sensitive proxy records. Geographically widespread positive temperature anomalies are observed from the 9th to 11th centuries, similar in extent and magnitude to the 20th century mean. A dominance of widespread negative anomalies is observed from the 16th to 18th centuries. Though we find the amplitude and spatial extent of the 20th century warming is within the range of natural variability over the last 12 centuries, we also find that the rate of warming from the 19th to the 20th century is unprecedented in the context of the last 1200 yr. The positive Northern Hemisphere temperature change from the 19th to the 20th century is clearly the largest between any two consecutive centuries in the past 12 centuries. These results remain robust even after removing a significant number of proxies in various tests of robustness showing that the choice of proxies has no particular influence on the overall conclusions of this study.

Citations

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