Global warming and Entropy [Entropy for Dummies]
Bob Thomson, Ottawa, 3 March 2009
Entropy is a measure of the amount of energy no longer able to be converted to work.
The
First and Second Laws of Thermodynamics state that the total amount of energy in the universe is fixed, and that new energy cannot be produced.
Energy
can only be transformed from one form to another, and in one direction
only, i.e. from useful energy to energy that is no longer available for
“work”.
For example, burning coal or falling water can be
transformed into motion or electricity, but ashes and lower level water
cannot be reused again without using other sources of energy.
Evolving energy/entropy paradigms
It
took millions of years for Homo Sapiens as hunter-gathers to largely
exhaust the supply of wild animal and vegetable food sources using
progressively more efficient tools, a period during which world
population grew and grew.
Populations pressures generated a new
energy paradigm in the transition to sedentary agriculture, which
permitted storage of food energy and led to specialization and
increased complexity within the human population.
It took
several thousand years before the human population outgrew the
agricultural energy paradigm. The reduction of forests and wood sources
in Europe in the Middle-Ages, the limits of domesticated animal energy
on land utilization, population pressures and other factors pushed the
development of new but still finite energy sources such as coal to
satisfy changing and growing human “needs”.
The industrial
“revolution”, after only a few short centuries now, has expanded the
consumption and transformation of finite energy to the point where the
byproducts and waste of energy production and use are now serious
limits on global productivity and further growth, not to say toxic and
disruptive of the climate and environment of the entire planet.
It
takes 9 calories of vegetable food “energy” to produce 1 calorie of
animal food “energy”. An average person needs 2000 calories per day to
survive. In our industrial society, this takes 200,000 calories of
energy to produce. Hunter gathers took only 15 hours a week to meet
their needs, i.e. 180 calories to produce 2000 calories!
In
a practical sense, the Second Law of Thermodynamics and the concept of
ENTROPY mean that we do not have unlimited sources of energy to fuel
further economic growth. The energy we currently derive from
hydrocarbons (coal, oil and gas) are the result of millions of years of
accumulation of incoming solar energy via plant photosynthesis on an
essentially finite planet.
We have now reached, or will soon
reach, the point of “peak oil”, i.e. the point at which we extract and
use hydrocarbon resources faster than we find new sources or develop
more efficient technologies to use them. Synthetic or agro-fuels and
new materials made from carbohydrates vs hydrocarbons (e.g. grown vs
extracted) are subject to the same limits of entropy.
Is new technology the solution? Yes/Maybe/But...
In
1865, English economist William Stanley Jevons discovered an efficiency
paradox: the more efficient you make machines, the more energy they
use. Why? Because the more efficient they are, the better they are, the
cheaper they are and more people buy them, and the more they'll use
them.
from:
Alec Dubro, The Myth of the Efficient Car “Decroissance” - Degrowth – No-Growth
There
is a growing civil society movement advocating degrowth, eco-economics
and many variants of a zero or even negative economic growth or a
steady-state approach. Voluntary simplicity is a key tenet for most of
this movement, advocating less work, more satisfaction
from social “consumption” than material consumption. This
doesn't necessarily mean a return to the cave. We need somewhere
between the 180 calories of hunter-gathers and the 200,000 calories of
industrial society to produce the 2000 calories we need each day
to physically survive. A major paradigm shift should be
possible once we learn to distinguish
between human “wants” and “needs” and to cooperatively redistribute the
existing over-accumulation of production, infrastructure and income.
We need a new “3 Rs”.
Renounce – Redesign – Rebuild
Because Reduce, Recycle and Reuse won't be enough
771 words to here