11
© Springer Nature Switzerland AG 2020
A. Kerényi, R. W. McIntosh, Sustainable Development in Changing Complex Earth Systems,
Sustainable Development Goals Series, https://doi.org/10.1007/978-3-030-21645-0_2
Structure and Operation
of Systems, Models of the Global
Earth System
2.1
Systems Basics
Systems are defined in a number of ways in various publications (Forrester 1968, 1971; Bennett
and Chorley 1978; Haggett 2001; László 2008a,
b). Taking general similarities from these definitions the following can be given.
A system is a self-organised or artificially created
collective of system elements that are in structural
connection and close interaction with each other
and at certain conditions it operates and reacts to
external effects as a unified whole.
Subjects and phenomena of objective reality
are in some kind of interaction with each other.
This is mostly realised in material and energy
flow. (In some system types information flow
also takes place.) Interaction between the given
objects (system elements) can be strong, weak,
direct or indirect thus in a defined part of the
space system elements (rectangles in Fig. 2.1) in
closer connection (interaction) form natural units
or systems. For scientific study the elements of a
system are separated from other elements of the
surrounding environment in order to study their
specifics in more detail.
Since every subject, material and process cannot be included in scientific research a part of reality is separated from its environment—in theory
most of the time—for scientific or practical study.
Within the system delineated in this way operational and structural connections exist between
system elements. The system has a natural boundary which has to be followed by the theoretical
delineation. Along the boundary of natural systems material and energy flow can be detected
generally. Boundaries of artificial systems are
determined by humans who created the systems
and they control the material and energy flows
between the system and its environment as well.
Numerous units and elements are connected in
a system. These elements can be materials,
objects, structures, processes (even theoretical
processes), activities, conceptions (e.g. conception system of scientific theories, mental systems
will be discussed later). The elements of a system
are connected not randomly they are rather based
on each other or have interaction, functional connections. The presence of functional connection
suggests that systems are not static; they operate
and change. Such movements involve material
and energy flows. In ecological and social systems
information flow is also fundamental although
such flows are realised via different information
carriers in the two system types. Maintaining
operation requires either some kind of an external
driving force or internal energy resource. For the
global system of the Earth the radiation energy of
the Sun as an external energy resource is decisive.
The energy of the internal heat of our planet also
has a significant role in the operation of the global
system; however, this significance is smaller than
that of the Sun (see later). The elements, units of a
system are placed according to a certain structural
order and form a greater unit.
2
© Springer Nature Switzerland AG 2020
A. Kerényi, R. W. McIntosh, Sustainable Development in Changing Complex Earth Systems,
Sustainable Development Goals Series, https://doi.org/10.1007/978-3-030-21645-0_2
Structure and Operation
of Systems, Models of the Global
Earth System
2.1
Systems Basics
Systems are defined in a number of ways in various publications (Forrester 1968, 1971; Bennett
and Chorley 1978; Haggett 2001; László 2008a,
b). Taking general similarities from these definitions the following can be given.
A system is a self-organised or artificially created
collective of system elements that are in structural
connection and close interaction with each other
and at certain conditions it operates and reacts to
external effects as a unified whole.
Subjects and phenomena of objective reality
are in some kind of interaction with each other.
This is mostly realised in material and energy
flow. (In some system types information flow
also takes place.) Interaction between the given
objects (system elements) can be strong, weak,
direct or indirect thus in a defined part of the
space system elements (rectangles in Fig. 2.1) in
closer connection (interaction) form natural units
or systems. For scientific study the elements of a
system are separated from other elements of the
surrounding environment in order to study their
specifics in more detail.
Since every subject, material and process cannot be included in scientific research a part of reality is separated from its environment—in theory
most of the time—for scientific or practical study.
Within the system delineated in this way operational and structural connections exist between
system elements. The system has a natural boundary which has to be followed by the theoretical
delineation. Along the boundary of natural systems material and energy flow can be detected
generally. Boundaries of artificial systems are
determined by humans who created the systems
and they control the material and energy flows
between the system and its environment as well.
Numerous units and elements are connected in
a system. These elements can be materials,
objects, structures, processes (even theoretical
processes), activities, conceptions (e.g. conception system of scientific theories, mental systems
will be discussed later). The elements of a system
are connected not randomly they are rather based
on each other or have interaction, functional connections. The presence of functional connection
suggests that systems are not static; they operate
and change. Such movements involve material
and energy flows. In ecological and social systems
information flow is also fundamental although
such flows are realised via different information
carriers in the two system types. Maintaining
operation requires either some kind of an external
driving force or internal energy resource. For the
global system of the Earth the radiation energy of
the Sun as an external energy resource is decisive.
The energy of the internal heat of our planet also
has a significant role in the operation of the global
system; however, this significance is smaller than
that of the Sun (see later). The elements, units of a
system are placed according to a certain structural
order and form a greater unit.
2