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has opened up possibilities to retrieve the change of global mean temperature for
five centuries. The data for 479 holes revealed the global warming by about 1.0 K
taking place during the last
five centuries. Only during the 20th century,
the
warmest one, an increase of the continents
surface temperature reached 0.5 K
(about 80 % of climate warming fell on the 19th
'
20th centuries). The warming
-
during the
five centuries had been stronger in the Northern Hemisphere (1.1 K) than
in the Southern Hemisphere (0.8 K). On the whole, the results obtained agree
with conclusions drawn on the basis of data on tree rings, though the latter
demonstrate a weaker centennial SAT trend, which can be explained by special
features of dendroclimatic methods.
Analysis of paleo-information on SAT obtained from the data on oxygen iso-
topes in Greenland ice cores for the Quaternary period has shown that long-term
temperature changes are superimposed by faster changes on time scales from
millennium to 10 years (Bowen 2000). An analysis of the Antarctic ice cores
revealed similar changes. In particular, in both polar regions, substantial changes of
temperature had taken place in the period of Holocene.
The data on plankton foraminifera Neogloboquadrina pachyderma from the
north-eastern region of the Atlantic (west of Ireland) made it possible to retrieve the
SST and trace the Heinrich events connected with icebergs
outbrakes.
Information on the content of carbon dioxide and methane in air bubbles con-
tained in ice cores re
'
ects an important role of those MGCs in climate formation.
For instance, it was shown that during four interglacial periods temperature in the
Antarctic had changed about 4,000 years earlier than changes of CO
2
concentration.
New results of numerical modeling of the dynamics of the El Ni
fl
ñ
o event caused
by variations of the orbital parameters, have satisfactorily followed
”
frequencies during the last 150,000 years as well as variations on a time scale of
about a millennium (Mor
“
Milankowich
sse 2001). However, most surprising was a
detection of climate variations with the period of 1,450 years from different data for
different regions of the globe, which had regularly repeated, in particular, in
Greenland during the last 110,000 years, including the last glaciation and Holocene
(an increase of the amplitude of such changes was observed in the periods of
glaciation). These results re
é
n and P
å
ect a radical reorganization of the climate system
taking place during comparatively short time periods. Holocene looked (compared
with these changes) like a period of comparatively stable climate. There is no doubt
that in the absence of climatic feedbacks, the growth of GHGs concentration in the
atmosphere should bring forth a climate warming. However, a real situation turns
out to be much more complicated, and to understand it, a reliable detection and
quantitative estimates of the role of feedbacks are needed. Otherwise, a reliable
forecast of climate change in the future is impossible. Since one of the very
important sources of respective information is peat-bogs, they should be thoroughly
protected.
Having analyzed the data of satellite observations of SST started from 1982,
Strong et al. (2000) noted a warming over most of the tropics and in mid-latitudes
of the Northern Hemisphere (with the global mean trend +0.005
fl
C per year not
exceeding the limits of observation errors). Less representative SH SST data reflect
°
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