The Spatial Extent of 20th-Century Warmth in the Context of the Past 1200 Years

2006/02/09 by Timothy J. Osborn, Keith R. Briffa · 14 citations
Earth and Planetary Sciences · Environmental Science · #Archaeology #Art #Climate variability and models #Climatology #Context (archaeology) #Geography #Geology #Geology and Paleoclimatology Research #History #Little ice age #Northern Hemisphere #Period (music) #Physical geography #Proxy (statistics) #Statistics #Tree-ring climate responses

paper · doi:10.1126/science.1120514

openalex publication_date 2006/02/09 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/23

Abstract

Periods of widespread warmth or cold are identified by positive or negative deviations that are synchronous across a number of temperature-sensitive proxy records drawn from the Northern Hemisphere. The most significant and longest duration feature during the last 1200 years is the geographical extent of warmth in the middle to late 20th century. Positive anomalies during 890 to 1170 and negative anomalies during 1580 to 1850 are consistent with the concepts of a Medieval Warm Period and a Little Ice Age, but comparison with instrumental temperatures shows the spatial extent of recent warmth to be of greater significance than that during the medieval period.

Citations

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Cited by

• Global climate change, war, and population decline in recent human history
• The importance of the geophysical context in statistical evaluations of climate reconstruction procedures
• Recent Warming Reverses Long-Term Arctic Cooling
• A new reconstruction of temperature variability in the extra‐tropical northern hemisphere during the last two millennia
• Reconstruction of the Extratropical NH Mean Temperature over the Last Millennium with a Method that Preserves Low-Frequency Variability
• A Bayesian Algorithm for Reconstructing Climate Anomalies in Space and Time. Part II: Comparison with the Regularized Expectation–Maximization Algorithm
• Northern Hemisphere temperature patterns in the last 12 centuries
• Millennial temperature reconstruction intercomparison and evaluation
• High-resolution palaeoclimatology of the last millennium: a review of current status and future prospects
• Robustness of the Mann, Bradley, Hughes reconstruction of Northern Hemisphere surface temperatures: Examination of criticisms based on the nature and processing of proxy climate evidence
• Description of the Medieval Warm Period and Little Ice Age in IPCC reports [wikipedia]
• Hockey stick graph (global temperature) [wikipedia]
• IPCC Fourth Assessment Report [wikipedia]
• Temperature record of the last 2,000 years [wikipedia]