NOAA NCDC National Climatic Data Center
NOAA Paleoclimatology Program, NCDC Paleoclimatology Branch  
Paleoclimatology Navigation Bar Bookmark and Share
NOAA National Environmental Satellite, Data, and Information Service National Oceanic and Atmospheric Administration NOAA National Climatic Data Center U.S. Department of Commerce Paleo Home Data Paleo Projects Paleo Perspectives Education and Outreach About Paleo Program Site Map GW Home Story Data End Site Map Global Warming Spanish Page Contact NOAA Paleo

Northern Hemisphere
Temperatures of the Last Six Centuries


Michael E. Mann, Raymond S. Bradley and Malcolm K. Hughes

Complete Scientific Reference


The Mann et al. reconstruction of annual northern hemisphere temperature is perhaps the most exhaustive and statistically rigorous reconstruction yet produced. Paleoclimate records from more than 100 sites were used. As in the work of Jones et al. (1998) and Overpeck et al. (1997), a "multi-proxy" approach (in this case using ice cores, corals, tree rings, historical records, and long instrumental records) was used which allowed the research team to make sure their results were not biased by potential problems with any one proxy source.

Mann et al. also investigated the role of different hypothesized climate forcing mechanisms in influencing hemispheric temperatures through time. They conclude that variations in the sun, volcanic eruptions, and human-induced increases of greenhouses gases (CO2 in particular) all played a role in generating the observed patterns of climate change over the last 600 years. They also conclude that greenhouse gases were the dominant forcing during the 20th century.

As with other state-of-the-art temperature reconstructions published in the last couple of years, the Mann et al. reconstruction indicates that the 20th century is the warmest of the last 600 years, and that 1998 is the warmest year of the last 600 years. This research has been updated in Mann et al 1999. Expanded reconstructions of Northern Hemispere temperature strongly suggest that the 1990s were the warmest decade and 1998 the warmest year of the past millennium.

Proxy records do not extend to the present day; for this reason the red star (located on the graph) marks approximate 1999 Northern Hemisphere Temperature.
Mann et al., graph
animation od mann study For larger viewing version of graph, please click here or on the graph.

Year by year maps of reconstructed climates have been produced for the last 260 years. The maps were produced for a scientific paper by Mann et al., 1998. Click here for complete scientific reference. To view animated maps of climate reconstructions, click here.

Link to Mann Data and FTP information...
Link to Mann et al 99 Data and FTP information...

On to the next study... "Overpeck et al., 1997."
Back to... "Paleo Data of the Last 2000 Years"

Dividing Line
Privacy Policy information Open Access Climate Data Policy link USA logo Disclaimer information
Dividing Line
Downloaded Tuesday, 17-Jan-2017 03:57:19 EST
Last Updated Wednesday, 20-Aug-2008 11:23:45 EDT by
Please see the Paleoclimatology Contact Page or the NCDC Contact Page if you have questions or comments.