CLIMATE RESEARCH
Clim Res
V
ol. 23: 89–110, 2003
Published January 31
1. INTRODUCTION
Are the Little Ice Age and Medieval Warm Period
widespread climatic anomalies? Lamb (1965) wrote,
‘[M]ultifarious evidence of a meteorological nature
from historical records, as well as archaeological,
botanical and glaciological evidence in various parts
of the world from the Arctic to New Zealand . . . has
been found to suggest a warmer epoch lasting several
centuries between about A.D. 900 or 1000 and about
1200 or 1300. . . . Both the ”Little Optimum” in the
early Middle Ages and the cold epochs [i.e. ”Little Ice
Age”], now known to have reached its culminating
stages between 1550 and 1700, can today be substanti-
ated by enough data to repay meteorological investi-
gation. . . . It is high time therefore to marshal the cli-
matic evidence and attempt a quantitative evidence’
(p. 14–15). Research on large-scale patterns of climate
change continued with vigor.
Jones et al. (199
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tentatively concluded that while
a Little Ice Age cooling existed, little evidence could
be found to support or reject a medieval warming. But
the updated composite tree-ring summer temperature
curve in Fig. 1 of Briffa (2000) shows evidence for an
anomalously warm interval from about 950 to 1100 in
the northern high-latitude zone, which coincides with
Lamb’s Medieval Warm Period. Also, a similar early
warm period appears prominently in the averaged
tr
ee
ring chronologies carefully selected and processed
fr
om
14 sites spreading over 30 to 70° N (Esper et al.
2002).
Those results are but a few of many that have be-
come available since Lamb’s analysis. Given advance-
ments in retrieval of information from and extension of
surface coverage for the proxies, we review the accu-
mulated evidence on regional climatic anomalies over
the last 1000 yr. We also recommend Ogilvie & Jónsson
(2001), who recently provided the most authoritative
discussion on the historical development of the long-
standing debates on the climatic nature of the Medi-
eval Warm Period and Little Ice Age, especially con-
cerning the North Atlantic, including Iceland.
© Inter-Research 2003 ·
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*Email:
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Proxy climatic and environmental changes of the
past 1000 years
Wi
llie Soon
1, 2,
*
, Sallie Baliunas
1, 2
1
Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS 16, Cambridge, Massachusetts 02138, USA
2
Mount Wilson Observatory, Mount Wilson, California 91023, USA
http://www.int-res.com/articles/cr2003/23/c023p089.pdf