Geoscience Reference
In-Depth Information
of climate change in the Arctic re
fl
ect natural climate cycles? Relevant major topics
include:
the medieval warm period (apparently, AD 1000
1400) and Little Ice Age
￿
-
(approximately AD 1400
1850);
-
high-amplitude Holocene climate cycles, and
￿
the possible connection of the onset of neo-glacial (a mid-Holocene cooling,
particularly evident at high northern latitudes) with shifts in the frequency and
amplitude of such climate cycles.
￿
According to the PARCS, there are very warm past scenarios that can serve as
analogues for future climate warming:
the early Holocene, when the Arctic had experienced high summer insolation
anomalies, and
￿
the last interglacial period (marine isotope stage 5), which appears as a very
strong warming in the paleo-record approximately 125,000 years ago.
￿
Key topics investigated in relation to these periods are:
￿
feedbacks and nonlinear changes (surprises) as consequences of strong warming
particularly the role of sea ice, ice sheets, and land surface cover;
implications of strong warming for arctic and global carbon budgets.
￿
To summarize what has been mentioned in connection with recent Arctic
environmental programs, it must be emphasized that relevant information was not at
all exhaustive (IASC 2001). An obvious conclusion is that the number of programs
is too great. A clear necessity exists of better coordination of all on-going efforts
and their
regularization
.
understanding the full
dimension of arctic change is a fundamental challenge to the scienti
V
ö
r
ö
smarty et al. (2001) are right in their conclusion that
c community
over the coming decades and will require a major new effort at interdisciplinary
synthesis. It also requires an unprecedented degree of international cooperation
.
As it was noted earlier, the Arctic region plays a unique role in the global
environmental processes, forming numerous adverse correlations with the Earth
s
climatic system. Low temperatures, a high level of atmospheric circulation and the
availability of large ice-covered aquatories are notable for the high latitudes, quite
unlike the other areas of the globe.
The intensive industrial development of the northern territories has led to sig-
'
ni
cant environmental change in these regions, especially in the Russian territories.
Oil and gas extraction on the Yamal and Taimir peninsulas in northwestern Siberia,
coal and gold extraction in Yakutia and Chukot as well as the mining industry on
the Kola Peninsula have led to a strong anthropogenic intervention into the natural
environment. Plant cover has been violated over great territories, the area and
productivity of reindeer pastures diminished and the hydrologic regime of rivers
disturbed. The greatest quantities of pollution substances are brought to the northern
coast of Russia by the rivers, violating the ecosystems of the northern seas.
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