The PAGES 2k Global Multiproxy Database for Temperature Reconstructions of the Common Era

Abstract:

In 2013 the PAGES 2k Consortium released a paleo-temperature database with more than 500 records from 7 continental-scale regions, along with continental-scale temperature reconstructions derived independent by expert groups for each region. A major motivation of this effort was to increase the amount of regional expertise involved in identifying and evaluating paleoclimate records for their use in temperature reconstructions. The project highlighted the value of engaging regionally-based expertise in paleoclimatology; however, the resulting database was somewhat disjoint, as each group assembled data independently with somewhat distinct goals and criteria, which hindered the use of the database to answer questions that span across multiple regions. Moreover, key data (e.g., native measurements, chronological uncertainties) and metadata (e.g., seasonality) were not included. Phase 2 of the PAGES 2k temperature database improves upon these shortcomings with a community-built flexible database that can be used to address major questions about the climate of the Common Era, and to refine the methodologies used to reconstruct it. As in phase 1, the database was built upon the expertise of dozens of paleclimatologists whose regional expertise spans the globe. Phase 2 of the temperature database includes about 800 temperature-sensitive timeseries, derived from ten archive types, including from the oceans. Here we present the characteristics and structure of the database, including a suite of diagnostics used to evaluate the fidelity of the temperature signal in the data. This includes their correlation with instrumental temperature data; however this assessment is not possible with all the records in the database, and we also recognize that such correlations are an imperfect metric of how strongly a timeseries reflects temperature throughout the Common Era. Consequently, we also explore other metrics, including how well each record corresponds with with nearby sites back through time. We also present a simple global index reconstruction for the Common Era. These first-blush analyses highlight the potential for further discovery with these data, and we encourage the paleoclimate community to take advantage of this open resource.