The claim that carbon dioxide (CO2) can increase air temperatures by
"trapping" infrared radiation (IR) ignores the fact that in 1909
physicist R.W. Wood disproved the popular 19th Century
thesis that greenhouses stayed warm by trapping
IR. Unfortunately, many people who
claim to be scientists are unaware of Wood's experiment which
was originally published in the Philosophical magazine , 1909, vol 17, p319-320.
Philosophical Magazine might not sound like the name of a science
publication, but a century ago leading scientists published their
discoveries in it.
During the early 19th Century many physicists supported
the theory postulated by Benjamin Franklin that heat
involved some type of fluid. The theory became known as "caloric
theory". Joseph Jean Baptiste Fourier's theory
that the atmosphere was heated from infrared radiation from
the ground was a variation of caloric theory with IR functioning as
the "fluid". Fourier believed greenhouses were heated by
trapping this radiation.
Physicists in the early 19th Century were attempting to develop
theories to explain the nature of atoms and their properties such as
heat. Physicists theorized that atoms were the smallest
particles of matter.
By the end of the century a new theory of heat, called "kinetic
theory", was being developed that suggested heat was the
motion, or kinetic energy, of atoms. However, Fourier's
theory that IR heated the atmosphere particularly by interacting
with carbon dioxide and water vapor continued to have support.
In 1897 J.J. Thompson overturned the popular theory of the atoms
being the smallest particles of matter by reporting his discovery of
the electron and predicting two other types of charged particles he
called protons and neutrons.
Wood was an expert on IR. His accomplishments
included inventing both IR and UV (ultraviolet) photography.
In 1909 he decided to test Fourier's theory about how greenhouses
retained heat.
Wood constructed two identical small greenhouses.
The description implies the type of structure a gardener
would refer to as a "cold frame" rather than a building a person
could walk into.
He lined the interior with black cardboard which would absorb
radiation and convert it to heat which would heat the air through
conduction. The cardboard would also produce
radiation. He covered one greenhouse with a sheet of
transparent rock salt and the other with a sheet of glass. The
glass would block IR and the rock salt would allow it to
pass.
During the first run of the experiment the rock salt greenhouse
heated faster due to IR from the sun entering it but not the glass
greenhouse. He then set up another pane of glass to
filter the IR from the sun before the light reached the
greenhouses.
The result from this run was that the greenhouses both heated to
about 50 C with less than a degree difference between the two.
Wood didn't indicate which was warmer or whether there was any
difference in the thermal conductivity between the glass sheet and
the rock salt. A slight difference in the amount of heat
transfered through the sheets by conduction could explain such a
minor difference in temperature. The two sheets probably
didn't conduct heat at the same rate.
The experiment conclusively demonstrates that greenhouses heat up
and stay warm by confining heated air rather than by trapping
IR. If trapping IR in an enclosed space doesn't
cause higher air temperature than CO2 in the atmosphere
cannot cause higher air temperatures.
The heated air in the greenhouses couldn't rise higher than the
sheets that covered the tops of the greenhouses. Heated
air outside is free to rise allowing colder air to
fall to the ground.
Atmospheric CO2 is even less likely to function as a barrier to IR
or reflect it back to reheat the ground or water than the sheet of
glass in Wood's greenhouse.
The blackened cardboard in Wood's greenhouses was a very good
radiator of IR as is typical of black substances. The water
that covers 70% of earth's surface is a very poor radiator and
produces only limited amounts of IR as is typical of transparent
substances. Water releases heat through evaporation
rather than radiation.
The glass sheet provided a solid barrier to IR. Atmospheric
CO2 is widely dispersed comprising less than 400 parts per million
in the atmosphere. Trapping IR with CO2 would be like
trying to confine mice with a chain link fence.
Glass reflects a wider spectrum of IR than interacts with CO2.
The glass sheets reflected IR back toward the floor of the
greenhouse. CO2 doesn't reflect IR.
At the time of Wood's experiment, it was believed that CO2 and other
gas molecules became hotter after absorbing IR.
Four years later Niels Bohr reported his discovery that the
absorption of specific wavelengths of light didn't cause gas
atoms/molecules to become hotter. Instead, the absorption of
specific wavelengths of light caused the electrons in an
atom/molecule to move to a higher energy state. After
absorption of light of a specific wavelength an atom couldn't absorb
additional radiation of that wavelength without first emitting light
of that wavelength. He called the amount of energy absorbed
and emitted as a "quantum". (Philosophical
Magazine
Series 6, Volume 26 July 1913, p. 1-25)
Unlike the glass which reflects IR back where it comes from,
CO2 molecules emit IR up and sideways as well as down.
In the time interval between absorbing and reemitting
radiation, CO2 molecules allow IR to pass them by. Glass
continuously reflects IR.
Those who claim that CO2 molecules in the atmosphere can cause
heating by trapping IR have yet to provide any empirical scientific
evidence to prove such a physical process
exists. The experiment by R.W. Wood demonstrates
that even a highly reflective covering that reflects a
broad spectrum of IR cannot cause heating by trapping IR in a
confined space. There is no way CO2,
which at best only affects a small portion of the
IR produced by earth's surface, can heat the atmosphere by trapping
IR.
Contrary to the lie repeated in news stories about climate, science
doesn't say that CO2 is causing higher temperatures by trapping
IR. Empirical science indicates that no such process
exists in this physical universe.
Thursday, September 24, 2020
Global Warming Theory Disproved a Century Ago
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