PAGES 2k Consortium

PAGES 2k Consortium
Name	PAGES 2k Consortium
Formation	2009
Type	Scientific collaboration
Headquarters	International
Fields	Paleoclimatology, Paleoclimatic reconstruction

PAGES 2k Consortium

The PAGES 2k Consortium is an international research collaboration focused on reconstructing regional and global climate variability over the past two millennia using proxy records. The group brought together researchers from institutions such as Max Planck Society, University of Cambridge, National Oceanic and Atmospheric Administration, Columbia University, and ETH Zurich to synthesize paleoclimate data and assess historical climate patterns relative to the instrumental era.

Overview

The Consortium emerged from the Past Global Changes (PAGES) project and coordinated efforts across networks including International Geosphere-Biosphere Programme, World Climate Research Programme, National Aeronautics and Space Administration, Swiss Federal Institute of Technology in Zurich, and regional centers like Scripps Institution of Oceanography and Lamont–Doherty Earth Observatory. It convened researchers who specialize in proxy archives such as Greenland ice core, Antarctic ice core, Tree ring, Coral reef, Lake sediment, Speleothem, Glacier, and Marine sediment records. The Consortium organized workshops modeled on meetings held at institutions like Royal Society, National Academy of Sciences, University of Oxford, European Geosciences Union, and American Geophysical Union.

Objectives and Scope

The Consortium aimed to produce standardized regional temperature reconstructions for the past two thousand years, clarify the timing and magnitude of events like the Medieval Warm Period, Little Ice Age, Volcanic winter of 1816, and multidecadal variability such as the Atlantic Multidecadal Oscillation and Pacific Decadal Oscillation. Objectives included methodological intercomparisons among teams at Princeton University, Yale University, University of Arizona, University of Bern, University of California, Berkeley, and University of Washington and to align proxy synthesis with model simulations from groups like Community Earth System Model, Hadley Centre, and Paleoclimate Modelling Intercomparison Project.

Methods and Data Sources

Analytical approaches used by the Consortium included hierarchical statistical models, principal component analysis, composite plus scaling, and proxy system modeling developed in collaboration with groups at University of Minnesota, Ohio State University, University of Melbourne, University of Tasmania, and University of Copenhagen. Data sources comprised published and unpublished proxy records archived in repositories such as NOAA Paleoclimatology, PANGAEA, and regional datasets curated by teams at University of Bern and University of East Anglia. Proxy-types integrated analyses from Dendrochronology specialists at McMaster University and Swiss Federal Institute for Forest, Snow and Landscape Research, Coral reef isotopic studies from Australian National University, and Speleothem chronologies from University of Innsbruck and Universidad Complutense de Madrid.

Key Findings and Publications

Major Consortium products included multiregional reconstructions and syntheses published in high-profile venues involving authors from Harvard University, University of Cambridge, University of Colorado Boulder, ETH Zurich, and University of Bern. Findings emphasized that late twentieth-century warming is anomalous in the context of the last two millennia, clarified spatial heterogeneity during the Medieval Warm Period and Little Ice Age, and quantified responses to forcings like Solar radiation variation and large volcanic eruptions such as Mount Tambora, Krakatoa, and Mount Pinatubo using comparisons with model output from NCAR and Met Office Hadley Centre. Publications were disseminated via collaborative papers in journals associated with editorial boards linked to Nature Geoscience, Science, and Geophysical Research Letters.

Impact on Paleoclimatology

The Consortium influenced standards for proxy compilation, calibration, and uncertainty quantification, informing assessments by intergovernmental bodies such as the Intergovernmental Panel on Climate Change and contributing to discourse at forums like the United Nations Framework Convention on Climate Change conferences and workshops at Smithsonian Institution. Its methodological developments affected downstream studies at Princeton University, Columbia University, University of Bergen, and Australian National University, and provided baselines for regional assessments in Europe, North America, Asia, Africa, and the Southern Hemisphere used by researchers at CNRS, CSIC, University of Cape Town, and Peking University.

Collaborations and Membership

Membership drew scientists affiliated with institutions including Max Planck Institute for Meteorology, Lamont–Doherty Earth Observatory, Scripps Institution of Oceanography, University of Bern, ETH Zurich, Columbia University, NOAA, NASA, Purdue University, University of Arizona, University of Cambridge, University of Oxford, University of Melbourne, Australian National University, and numerous national research councils like National Science Foundation and Swiss National Science Foundation. Collaborations extended to climate modelers, statisticians, and proxy specialists from centers such as NCAR, Met Office, Paleoclimatology Research Group at the University of Maine, and regional networks across Europe, Asia, Africa, and the Americas.

Criticisms and Controversies

The Consortium faced debate over proxy selection, regional coverage biases, and reconstruction methodologies, with critiques voiced by scholars at University of Delaware, University of Alabama, George Mason University, University of Notre Dame, and critics referencing earlier controversies like the Climatic Research Unit email controversy. Discussions centered on sensitivity to screening criteria, treatment of replication and chronology, and interpretation of spatially heterogeneous signals versus global means, engaging statistical perspectives from Stanford University, University of Washington, and Carnegie Mellon University. The Consortium responded through transparent data sharing, methodological intercomparison studies, and subsequent updates that incorporated broader proxy networks and advances from groups at Potsdam Institute for Climate Impact Research and Los Alamos National Laboratory.

Category:Paleoclimatology