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ENVS 1000 Chapter n/a: (Module 3) ENVS1000 - Fall Term - Notes


Department
Environmental Studies
Course Code
ENVS 1000
Professor
Peter Timmerman
Chapter
n/a

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ENVS 1000: F Sept. 24th, 2014
Module 3: Boom and Bust: Ecology and Society
GAIA and the Earth System
Timmerman, P. (2009). GAIA And The Earth System. Retrieved September 24, 2014, from Moodle.
https://moodle.yorku.ca/moodle/pluginfile.php/1093616/mod_resource/content/3/Gaia_and_the_
Earth_System.pdf
Overview
A brief introduction to some basic tools of the environmental trade, including population growth,
competition for resources, ecological niches, the “J curve” and the “S curve”. These are explored through
examples of environmental needs and history.
Definitions
Spectral analysis is a way of determining the chemical composition of things from a distance through
analysis of the light radiating from, or reflecting off them.
GAIA it is a self-regulating system is itself what some people would call an organism. It was a single big
motherly organism.
Entropy can be loosely defined as the universal degrading of energy, of which the most familiar form for
earth processes is the degrading of “high class” solar energy to waste heat.
Photosynthesis is a complex series of processes carried out by plants and algae, and what are called
cyanobacteria.
Phosphates is a form of phosphorus
Notes
GAIA and the Earth System
Searching for Life on Earth
-In the last 40 years, a number of scientific revolutions have taken place, ranging from the acceptance
of theories of continental movement on massive plates as driving forces for earth system changes to
the Gaia hypothesis.
Across many disciplines a series of mutually enlightening discoveries have completely transformed
our understanding and awareness of the Earth.
Astronomy, planetary science, paleontology, geology, biochemistry
Dynamic system
-Spectral analysis
When light is reflected off or travels through different materials w/ different chemical composition,
their spectral pattern is different, characterized by Fraunhofer lines or gaps in the spectrum. These
are gaps where the object’s chemical constituents absorb rather than reflect light.

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The Gaia Hypothesis
-The Gaia hypothesis, which is one of the great 20th century scientific ideas.
-In the late 1960’s there were proposals raised to send a probe a person to Mars at that time, was life
on Mars.
-Jim Lovelock:
Is an independent scientists, who had been one of the first to detect chlorofluorocarbons in the
Antarctic – chlorofluorocarbons are the main source of problems in the ozone layer – was hired to
help think though this problem.
Spectrum analysis of the planets Venus and Mars that is a spectrum gives you the chemical
composition of the planet depending on the reflective properties of he gases and elements involved
these planets are essentially at chemical equilibrium. This is a chemical term.
If you take a number of chemicals that can react w/ each other, and you put them in a test tube
together, and you let the processes rip, eventually all the processes will be carried out, and you
will be let w/ the product of the reaction. This is playing out of entropy, the running down of
physical and chemical system.
If you contrast w/ the Earth, you find that among, other things, there is 21% oxygen, which is
an incredibly reactive gas, and all sorts of other detectable products which suggest that there
is intensive activity going on, keeping these gases gar from equilibrium.
The evidence of the chemical composition of the atmosphere alone not only indicated that there was
life on earth, but that the atmosphere was a continuing product of the biosphere – that is, it was
sustained by the array of organisms on the planet.
Lovelock then went on to argue that the Earth was itself a self-regulating system, which he called
GAIA.
1. One problem is that it is not subject to competition, so far at any rate.
2. Second problem, it is the platform for organisms, w/in which organisms function, so while it is
plausible that it might be a superorganism, it is more or less is its own environment, except of course
for the sun, deep space and the occasional rain of comets and meteors.
3. Third problem, and most complex of all, it is hard to see how all individual organisms, working for
their own survival, should somehow also be working for the larger environment for which they are a
part – this is one of the reasons why a holistic, organic metaphor arose.
It is also important to stress that there are complications to the Gaia hypothesis.
The fact that many of the processes that involve elements like oxygen are strongly regulated
by non-living physical and chemical processes, such as: weathering, volcanism, and other.
Also some of the early claims about biological regulatory processes are now seen more
skeptically.
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