Climate Over Past Millennia 
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                NOAA Paleoclimatology Program
                               and
         World Data Center for Paleoclimatology, Boulder
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NOTE: PLEASE CITE ORIGINAL REFERENCE WHEN USING THIS DATA!!!!!


NAME OF DATA SET: Climate Over Past Millennia 
LAST UPDATE: 12/2004 (Original Receipt by WDC Paleo)

CONTRIBUTORS: P.D. Jones and M.E. Mann
IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2004-085


SUGGESTED DATA CITATION: Jones, P.D. and M.E. Mann. 2004.
Climate Over Past Millennia.
IGBP PAGES/World Data Center for Paleoclimatology 
Data Contribution Series #2004-085. 
NOAA/NGDC Paleoclimatology Program, Boulder CO, USA. 


ORIGINAL REFERENCE: Jones, P.D. and M.E. Mann. 2004.
Climate Over Past Millennia. 
Reviews of Geophysics 42, RG2002, 6 May 2004. 

ABSTRACT:
We review evidence for climate change over the past several millennia 
from instrumental and high-resolution climate "proxy" data sources and 
climate modeling studies. We focus on changes over the past 1 to 2 millennia. 
We assess reconstructions and modeling studies analyzing a number of different 
climate fields, including atmospheric circulation diagnostics, precipitation, 
and drought. We devote particular attention to proxy-based reconstructions of 
temperature patterns in past centuries, which place recent large-scale warming 
in an appropriate longer-term context.  Our assessment affirms the conclusion 
that late 20th century warmth is unprecedented at hemispheric and, likely, 
global scales. There is more tentative evidence that particular modes of 
climate variability, such as the El Nino/Southern Oscillation and the 
North Atlantic Oscillation, may have exhibited late 20th century behavior 
that is anomalous in a long-term context. Regional conclusions, particularly 
for the Southern Hemisphere and parts of the tropics where high resolution 
proxy data are sparse, are more circumspect. The dramatic differences between 
regional and hemispheric/global past trends, and the distinction between changes 
in surface temperature and precipitation/drought fields, underscore the limited 
utility in the use of terms such as the "Little Ice Age" and "Medieval Warm Period" 
for describing past climate epochs during the last millennium. Comparison of 
empirical evidence with proxy-based reconstructions demonstrates that natural 
factors appear to explain relatively well the major surface temperature changes
of the past millennium through the 19th century (including hemispheric means and 
some spatial patterns). Only anthropogenic forcing of climate, however, can explain 
the recent anomalous warming in the late 20th century.


GEOGRAPHIC REGION: Global
PERIOD OF RECORD:  200 - 1995 AD

  
DESCRIPTION:   
The data files contain the raw and smoothed (i.e. as plotted) data for some of 
the plots in Jones and Mann 2004. If the files are used in any paper, report or 
other form of publication, then please acknowledge the Reviews of Geophysics paper 
together with the specific original references to any series used. 

Data for the series used in Figures 2, 4-7 and 8 are mostly available. Some series 
are missing as we have been asked not to make these freely available. For these, 
you will have to contact the appropriate author(s). 

For some, but not all files, we have included the raw data together with the 
smoothed data as plotted. Most of the series are in anomalies, from periods given 
in the figure captions of the paper. Some series are only available as smoothed 
versions and some raw series are scanned versions from the original papers 
(i.e. also smoothed to varying degrees). 

File contents:

Figure 2.  
jonesmannrogfig2c.txt:  
Instrumental temperature, 20-year smoothed annual average values for the Northern Hemisphere 
(from HadCRUT2v), central Europe, Fennoscandia, and central England. 


Figure 4.  Local and regional proxy temperature reconstructions by continent. 
jonesmannrogfig4a.txt:  Western North America 
jonesmannrogfig4b.txt:  North Atlantic
jonesmannrogfig4c.txt:  Europe 
jonesmannrogfig4d.txt:  Eastern Asia 
jonesmannrogfig4e.txt:  Tropics 
jonesmannrogfig4f.txt:  Tasmania

Figure 5.
jonesmannrogfig5.txt:   Global/Hemispheric mean annual temperature reconstructions

Figure 6.
jonesmannrogfig6a.txt:  Reconstructions of the Southern Oscillation Index (SOI) 
jonesmannrogfig6b.txt:  Reconstructions of the North Atlantic Oscillation (NAO)

Figure 7.
jonesmannrogfig7.txt:   Estimates of natural and anthropogenic radiative forcings 
                        over the last couple of millennia used by climate models 
                        to simulate the climate over the period.

Figure 8.
jonesmannrogfig8.txt:   Model-based estimates of N. Hemisphere temperature variations 
                        over the past two millennia. 


jonesmann-nhrecon-rescale.txt:
Re-scaled Jones-Mann 2004 N.Hemisphere temperature reconstruction, to the same decadal 
standard deviation as the instrumental record over the 1856-1995 period.