Dear Sergio,
I am sorry if I upset you with my example of Dutch tomatoes. But this
"ecological niche" seems rather viable despite the lack of sunshine in
this country. My point was about the construction of ecological niches
which can be sustained for shorter or longer periods of time. For
example, the polder landscape in Holland is now sustainable for more
than a few centuries. (My house, for example, is at six meters below the
normal sea level.)
One can always question an assumption used as relevant for the
construction of a social system and then show that it is not sustainable
at a longer-term perspective. The question is the sustainability of the
ecological niches in which we live. These are constructs which can be
reconstructed. When a dimension is added to the reconstruction all bets
on the basis of the previous system are off because a dimension is added
to the system. The maximum entropy is then multiplied. This
consideration explains why high-tech systems are often better
sustainable than low-tech ones. The tomato example illustrates the
point. The eco-tax of the EU did not help the natural tomatos. One may
regret this, but this is not incidental. There is no alternative to
knowledge-based innovations.
With kind regards,
Loet
_____
Loet Leydesdorff
Amsterdam School of Communications Research (ASCoR)
Kloveniersburgwal 48, 1012 CX Amsterdam
Tel.: +31-20- 525 6598; fax: +31-20- 525 3681
<mailto:loet@leydesdorff.net> loet@leydesdorff.net ;
<http://www.leydesdorff.net/> http://www.leydesdorff.net/
<http://www.upublish.com/books/leydesdorff-sci.htm> The Challenge of
Scientometrics ; <http://www.upublish.com/books/leydesdorff.htm> The
Self-Organization of the Knowledge-Based Society
-----Original Message-----
From: fis-bounces@listas.unizar.es [mailto:fis-bounces@listas.unizar.es]
On Behalf Of Sergio Ulgiati
Sent: Saturday, December 13, 2003 4:42 PM
To: FIS Discussion List
Subject: [Fis] Again about coupling resources and information
Dear FIS Colleagues,
Sorry for not replying in the last week, due to real overload for other
commitments. Let me try to say something about the "value" problem
raised in several recent postings. In so doing, I also would like to
remove some misunderstandings about my last message.
a) Pedro quotes one sencence from my message out of the right context
("seeds, money, DNA, books, software, religions, cities, database, have
no hope to last, reproduce, or even survive against the law of entropy,
if resource flows are not provided every day to counter their
degradation.") and says that it implies hard-core reductionism. He makes
me to say something that I never said (the need for entropy analysis of
DNA or of seeds!) and then states that this is wrong.I agree, of
course.In fact I never said this. I said something that is much more
different and that Luis clearly summarizes in his posting: whatever we
do (be it making a house, teaching or thinking) we need resources:
building material, energy, food, water, electricity to power our
computer, energy and resources to keep the whole University system
working. Due to the entropy degradation, further maintenance is needed
at the expenses of additional resources. Making and disseminating copies
of the achieved information is the strategy that ecosystems as well as
humans follow (1) to avoid information losses, (2) to make it tested by
"trial and error" processes and (3) to move on to the new information
levels or dimensions pointed out by Loet. Resources and energy are a
pre-requisite for any of such activities (Enzo underlines this very
clearly in his message; Luis correctly talks about "energy that we have
available for a sustainable development"). These resources can be
misused or even lead to the creation of Leonardo's "Mona Lisa": the
quality of the result (we may say: its information content) is not
directly proportional to the input of resources, nor these two aspects
appear to be linked in any quantifiable way (although a qualitative link
cannot be denied). Yet, no resources, no result (no information). The
sun generates information via the photosynthetic process (sometimes we
talk of a flow of negentropy from the sun). The following steps (i.e.
the ways and the extent of biodiversity generation) cannot be easily
linked to the amount of solar negenergy, since they depend on the
evolution process, where several other factors affect the system (e.g.
scarcity of nutrients, chaotic fluctuations of any environmental
parameters, choices). Yet, again, no solar radiation, no photosynthesis,
no further steps.To point out that material and energy resources are a
pre-requisite does not mean to claim that we are able to "force" the
evolutionary process and drive it where we like. It only means that
resources are important and that their good use and conservation are of
primary importance for future development. Everybody knows that some
resources can be replaced by others, but this is not true for every
resource, nor it is true for the solar radiation. Even if the "stone age
did not end for lack of stones", our sustainability may be significantly
affected by lack of primary resources or by the disruption of the
environmental context (another kind of resource) in which our activities
develop ("Supply-Side Sustainability", Allen, Tainter and Hoekstra,
2002).
b) Pavel refers to me by saying that "basic analysis of energy flows and
"stocks" tells very little about information content of the system". I
agree. In fact I never said that we know the information content of
something by knowing its energy content.The information content of
something is so hard to explore and describe, that even thinking of its
quantification is almost impossible. The problem here is that energy
analysis is a First Law method, while Exergy and Emergy analyses are
Second Law-based and take into account the entropy generation occurring
when a resource is generated (emergy) or used (exergy). This is not
without interesting consequences.
Exergy ("the amount of work obtainable when some matter is brought to a
state of thermodynamic equilibrium with the common components of the
natural surroundings by means of reversible processes, involving
interaction only with the above mentioned components of nature", Szargut
et al., 1988) measures the physical and chemical "information" of an
item in relation to its conversion into useful work (mechanical,
electric, etc). Since exergy refers to reversible processes (and real
processes are never reversible), it states very clearly an upper limit
to the work obtainable and allows a sustainability assessment mainly
focussing on the way resources are used and on what can be obtained from
them (i.e. an user-side sustainability). Of course, we are not talking
here of the exergy of a person or a standing tree, since exergy is not
sensitive to life (using Luis' words). Herefore, we do not use exergy to
measure the work of an artist or the complexity of a flower or fruit (as
Enzo also pointed out).
As far as emergy is concerned, I would like to clarify that emergy is
not energy. It is the memory of the resources previously used up in a
process (by the way, measured in exergy terms_ Odum, Environmental
Accounting, 1996) during the whole pathway from primary inputs to the
final product. By measuring input flows by means of their exergy
content, emergy calculations acquire a "built-in" ability to account for
local scale entropy production. In addition, by integrating exergy
inputs over time and space for the calculation of transformities,
natural trial-and-error processes are also considered, thus taking into
account the production of entropy during the "metabolic" processes
leading to the final product via a set of intermediate steps. Therefore,
by converting all inputs into only one form unit (e.g. solar equivalent
joules), by means of suitable conversion coefficients, we measure the
(sometimes very approximate) environmental support that is required for
a process to occur. Since the ultimate sources of resources are
flow-limited (solar, deep heat, gravitational potential), the higher the
support demand, the less renewable the product. In some a way, this is a
measure of source-side sustainability. Edgar suggests in his posting
that the "virtual" replacement of non-renewable resources has a cost
which could be measured in exergy terms.
Source-side sustainability and user-side sustainability are useful
categories to better understand a process dynamics in terms of upstream
and downstream flows. They are NOT, however, deterministic measures of
what will happen within the system thanks to the resources supplied to
it. The system reacts in many different unpredictable ways to the
resource flows and some of these ways will be selected by the natural
selection.
Luis is right when he underlines the need for a further effort to find a
measure of the organizational level of an ecosystem also in relation to
life. Unfortunately, measuring what already happened and what is
presently happening is relatively easy, while predictions are quite
difficult and maybe impossible. Sven Jorgensen, University of
Copenhagen, made interesting steps ahead towards assessing and modelling
the level of organization of an ecosystem, by also including "Shannon"
estimates of species diversity. His goal-function is also called exergy,
but maybe it should be given a different name.
Let's now turn to Loet's Dutch tomatoes: what he says is simply
impossible. Photosynthesis cannot occur without solar radiation.
Replacing the sun by means of electric light is in principle possible
(the growth of plants under artificial light has been already
investigated), but would require a tremendous input of fossil fuels to
power the electric plant and a consequent related atmospheric pollution.
In general, greenhouse tomatoes in cold climates require a greenhouse
(plastics or glass, concrete and structure metals), an artificial
substrate (such as rock wool), fertilizers, several added chemicals as
pesticides and micronutriens, and a huge heat from fossil fuels. It is
completely unsustainable from a resource availability and environmental
constraint point of view. There are several studies on this topic, from
which it can be clearly inferred that the economic sustainability of
this practice only relies on the existence of cheap fossil fuels as well
as on neglecting the environmental aspects of their use (contribution to
the greenhouse effect increase, among other problems). In addition,
greenhouse tomatoes represent a simplified ecosystem and a significant
loss of biodiversity, since they are selected to fit greenhouse
conditions and survive in a very artificial atmosphere. I already
pointed out this kind of contradiction when Loet claimed that we can
have plenty of paper, ignoring the constraints imposed by the huge
(source and sink side) environmental problems generated by paper
production. This is what generally happens when we ignore the physical
constraints within which all our actions are embedded. Adding new
dimensions has a resource and environmental cost and resources are very
often non-renewable, no matter how we measure them. Greenhouse tomatoes
cannot be considered a sustainable new dimension.
If we care the development of information and the growth of sustainable
systems able to generate and maintain information, we must pay a huge
attention to our resource basis. Ecosystems do not grow without
resources, Universities decline when funding is not appropriate,
economies and Empires collapse and are replaced by competing systems
when their resource basis shrinks.
The following references may be useful at this regard:
Tainter J., 1988. The collapse of complex societies. Cambridge, England:
Cambridge University Press.
Odum H.T. and Odum E.C., 2001. A Prosperous Way Down: Principles and
Policies. University Press of Colorado.
I am also attacching a recent paper from Hall et al., Hydrocarbons and
the evolution of human culture, published in the Issue 426 of Nature, 20
November 2003, which you may find of some interest.
Greetings to all.
Sergio
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - -
Sergio Ulgiati
Energy and Environment Research Unit
Department of Chemistry
University of Siena
Via Aldo Moro
53100 Siena (Italy)
------------------------------------------------------------------------
------
Phone: +39-0577-234232
Fax: +39-0577-234254
E-mail: ulgiati@unisi.it
http://www.chim.unisi.it/energy/
http://www.chim.unisi.it/portovenere/
http://www.chim.unisi.it/zerind/
http://www.chim.unisi.it/enwar/
Received on Mon Dec 15 11:14:52 2003
This archive was generated by hypermail 2.1.8 : Mon 07 Mar 2005 - 10:24:46 CET