16
seems to be most likely but with enormous investment and over a very long time). This time is still
very far away (Box 2.1). This of course also means
that our primary task is to preserve the Earth in a
habitable state because for a long time only this
planet can provide our living conditions.
In summary, material systems according to their
relationship with their environment are classified
as isolated, closed, practically closed and open systems, however, the same system may be classified
into different groups depending on the different
aspects of study. In Earth’s environment natural
environmental systems are always open systems.
Recently some newspapers, scientific educational publications and TV shows illustrate the
severity of the deteriorating environment on
Earth with that humanity will need to search for a
new place for life in the “near” future either
within the solar system or outside it. Climate
change is set as an example most frequently
according to which 6 °C of temperature rise
would result in so severe consequences that could
lead to the end of the human race.
2.2
Operation of Material
Systems
2.2.1 Feedbacks
Both natural and artificial systems are capable of
self-regulation to some extent. The basis of selfregulation is feedback that operates even in simple systems. Feedback is an operation of the
Box 2.1 Will Humans Move from Earth?
Currently the global surface median temperature is 15 °C which would rise to 21 °C
according to this scenario. This would cause
significant challenges for humanity and
serious conflicts will need to be solved but
would not result in the complete extinction
of humans. It is worth thinking over what
would moving people meet on Mars, the
sole planet realistically accessible in the
coming 100 years. There the global surface
median temperature is −60 °C, temperatures rarely rise above freezing and only in
certain places for a short period of time. In a
practically permanently frozen environment
the survival of humanity can be hardly
imagined especially if the rest of the environmental conditions are also considered.
Practically there is no free oxygen in its
atmosphere and atmospheric pressure is a
hundredth of that on Earth. Any of the above
two conditions would mean that human life
on Mars is impossible without technical
interventions. Furthermore, there is no protective layer in the atmosphere of Mars like
the ozone shield in the atmosphere of Earth
that would protect humans against the ultraviolet short wavelength radiation of the
Sun. Although water can be found under the
surface of Mars mostly in the form of ice its
exploitation and turning it suitable for
human utilisation would require high
amount of energy the sources of which are
not available. The “solution” of those
visioning the move for the above would be
to transform the environment of Mars similar to that of Earth, a process called terra
formation. Not going into details, the
authors of the present book would like to
call attention only to the time required for
this: in an absolutely optimal case terra formation would require 100,000 years if
indeed it was successful. (For comparison,
the history of human civilisation on Earth is
only around 5000 years.)
Considering all the above, Earth will be
still a more habitable place for humans in
the solar system if the unwanted anthropogenic environmental changes cannot be
hindered. Of course, we may create much
worse conditions compared to those of
today. Why we ruin our own living place?
Would not it be wiser to preserve our planet
in its current state? These questions are
especially important if we know that we
will have no place to go for a long time.
2 Structure and Operation of Systems, Models of the Global Earth System
seems to be most likely but with enormous investment and over a very long time). This time is still
very far away (Box 2.1). This of course also means
that our primary task is to preserve the Earth in a
habitable state because for a long time only this
planet can provide our living conditions.
In summary, material systems according to their
relationship with their environment are classified
as isolated, closed, practically closed and open systems, however, the same system may be classified
into different groups depending on the different
aspects of study. In Earth’s environment natural
environmental systems are always open systems.
Recently some newspapers, scientific educational publications and TV shows illustrate the
severity of the deteriorating environment on
Earth with that humanity will need to search for a
new place for life in the “near” future either
within the solar system or outside it. Climate
change is set as an example most frequently
according to which 6 °C of temperature rise
would result in so severe consequences that could
lead to the end of the human race.
2.2
Operation of Material
Systems
2.2.1 Feedbacks
Both natural and artificial systems are capable of
self-regulation to some extent. The basis of selfregulation is feedback that operates even in simple systems. Feedback is an operation of the
Box 2.1 Will Humans Move from Earth?
Currently the global surface median temperature is 15 °C which would rise to 21 °C
according to this scenario. This would cause
significant challenges for humanity and
serious conflicts will need to be solved but
would not result in the complete extinction
of humans. It is worth thinking over what
would moving people meet on Mars, the
sole planet realistically accessible in the
coming 100 years. There the global surface
median temperature is −60 °C, temperatures rarely rise above freezing and only in
certain places for a short period of time. In a
practically permanently frozen environment
the survival of humanity can be hardly
imagined especially if the rest of the environmental conditions are also considered.
Practically there is no free oxygen in its
atmosphere and atmospheric pressure is a
hundredth of that on Earth. Any of the above
two conditions would mean that human life
on Mars is impossible without technical
interventions. Furthermore, there is no protective layer in the atmosphere of Mars like
the ozone shield in the atmosphere of Earth
that would protect humans against the ultraviolet short wavelength radiation of the
Sun. Although water can be found under the
surface of Mars mostly in the form of ice its
exploitation and turning it suitable for
human utilisation would require high
amount of energy the sources of which are
not available. The “solution” of those
visioning the move for the above would be
to transform the environment of Mars similar to that of Earth, a process called terra
formation. Not going into details, the
authors of the present book would like to
call attention only to the time required for
this: in an absolutely optimal case terra formation would require 100,000 years if
indeed it was successful. (For comparison,
the history of human civilisation on Earth is
only around 5000 years.)
Considering all the above, Earth will be
still a more habitable place for humans in
the solar system if the unwanted anthropogenic environmental changes cannot be
hindered. Of course, we may create much
worse conditions compared to those of
today. Why we ruin our own living place?
Would not it be wiser to preserve our planet
in its current state? These questions are
especially important if we know that we
will have no place to go for a long time.
2 Structure and Operation of Systems, Models of the Global Earth System