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(3) What mechanisms control the ability of ecosystems to rapidly restore and what
are indicators that re
fl
ect this ability of ecosystems?
How do an introduction of new species to ecosystems and an appearance of
new unstudied diseases affect the development of biogeochemical cycles in
land and water ecosystems?
What feedbacks between ecosystems and climate are critical and how these
feedbacks are parameterized in computer models?
Can the data on the past biogeochemical cycles be used for their prediction
in the future?
What basic parameters and characteristics of ecosystems affect their ability
to restore after anthropogenic forcings?
The global CO
2
biogeochemical cycle is in the centre of attention of scientists.
Specialists of many countries try to answer the following questions:
(i) What concentrations of CO
2
can be expected in future with present or
predicted rates of organic fuels burning?
(ii) What climate changes can result from increased concentrations of CO
2
?
(iii) What are consequences of climate changes for the biosphere?
(iv) What can the mankind undertake in order to either reduce negative con-
sequences of climate change or prevent them?
Clearly, according to rough model estimates, the industrial civilization should
now search for new sources of energy which would decrease the rates of organic
fuel burning and, hence, reduce the external forcings on natural biogeochemical
cycled. The atmosphere is one of the important reservoirs taking part in formation
of these cycles. On the whole, chemistry and physics of the atmospheric processes
suffer changes, without a study of which reliable assessment of the state of the
atmosphere and the dynamics and photochemical processes in it is impossible
(Brasseur 2005).
During the last decade the words
could be seen in numerous
publications on the problems of global climate change on Earth (Ichikawa 2004).
This term implies a totality of descriptions of the effects appearing in the climate
system and connected with a number of natural and anthropogenic processes. On
the whole, the notion of the greenhouse effect refers to an explanation of changes in
the atmospheric thermal regime, as a result of the impact of some gases on the
process of solar radiation absorption. Many gases are characterized by a high
stability and long residence in the atmosphere (Table
1.7
). Carbon dioxide is one of
them. As for the role of CO
2
, more than a century ago, Arrhenius (1896) was the
“
greenhouse effect
”
first to draw the conclusion that its emission in fuels burning can lead to a climate
warming. In subsequent decades this sagacious conclusion turned out to be a weird
foresight and sorrowful forecast. After all, in the global historical long-range per-
spective, CO
2
content in the atmosphere had been changing stably with variations
of about 20 ppm, at least, during 11,000 years before the industrial epoch. In this
long-term context the anthropogenic increase of atmospheric CO
2
by
100 ppm
for the last 200 years is a dramatic change in the global carbon cycle. This increase
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