In the latest legislative session in Washington state, Gov.
Jay Inslee proposed a carbon tax which will penalize anyone the government
deems is producing an excessive amount of CO2. The stated purpose of this tax
to mitigate the damage caused by global warming the results from CO2 being
released into the atmosphere.
This punitive tax is based on poor science, circular
reasoning and media-fueled hysteria. Any effort to curb CO2 emissions will do
exactly nothing to affect worldwide temperatures, if they are even a problem. I
will prove this here.
I am a NARTE
certified electromagnetic compliance engineer with more than 30 years practical
experience in high power radio frequency and microwave applications. The
principles of radio frequency propagation and free space loss in the RF frequency
domain are identical to the infrared region. My critique of the CO2 driven
climate change theory is based on a practical understanding of the intersection
between chemistry and electromagnetic theory. I am also a systems engineer with
plenty of experience in software design and development. I’ve had a lifetime
fascination with astronomy and cosmology, which is given me an intimate
familiarity with the principles of spectral absorption which are necessary to
understand CO2’s role as a greenhouse gas. I acknowledge the work done by
climatologists based on their study of global trends and their comparative
studies of CO2 levels. I challenge their conclusions, based on the
understanding of how CO2 acts in the atmosphere; and suggest that they explore
alternate explanations for their observations.
This explanation is going to be technical, but I will
explain the principles as I go, and anyone with a science background can
duplicate my analysis.
Global Warming (or is it Climate Change?)
No one was even aware that a problem existed until 2006,
when former VP Al Gore grossed $24 million in box office sales with his
propaganda-laden exposé,
An Inconvenient
Truth. Gore filled an hour and forty minutes with anecdotal evidence
cherry-picked to support his claims, claiming that 97% of scientists supported
his conclusions, even though
nothing of the sort was true. The linchpin of his proposal was a study by Mann,
Bradley and Hughes, which resulted in the famous hockey stick graph. Gore
projected this graph into the future and predicted dire consequences as a
result.
Without even studying the basis for this claim, this set my
alarm bells ringing. Climate is a chaotic system. It’s a system with dozens, if
not hundreds, of attractors which influence the end result. Small changes in
any one of the systems or attractors that influence climate can have dramatic
effects on the overall system. This is the very definition of chaos.
Anyone who is studying chaos theory knows that chaotic
systems tend to behave similarly, even if they have nothing to do with each
other. Another example of a chaotic system which frequently generates
short-term trends like Al Gore’s hockey stick graph is the stock market. What
Al Gore is essentially doing is looking at a short-term trend, projecting it
forward and concluding that huge profits are in store. Anyone who is a done any
trading in the stock market knows that this is a fallacy. Yes, sometimes
short-term trends turn in the long-term trends, and if you invested the
beginning of the short-term trend you can turn a handsome profit. The problem
is that chaotic systems have feedback loops, and the feedback loops have
feedback loops, and nine times out of ten your short-term trend is going to
reverse the moment you invest. If Al Gore is such a fan of projecting trends,
he should become a stock market analyst and get rich. Good luck to him.
I figured in 2006 that the short-term hysteria that he
generated would soon be forgotten. But Al Gore wasn’t about altruistically
warning us about and ecologic disaster. His movie was the opening salvo of a
marketing campaign designed to make billions of dollars through the creation of
a carbon credit exchange, where large producers of CO2 could “buy” carbon
credits from others who didn’t produce CO2. This exchange would function just
like the stock market, with the market makers taking a cut off of every
transaction. Of course, Al Gore was setting himself up to be one of the market
makers. Gore spent huge amounts of money promoting his climate change religion,
literally going on tour to convince people to invest in his carbon exchange. He
used his political capital to influence sitting lawmakers to pass legislation
to support his scheme. Tremendous amounts of money were spent in the form of
grants to generate studies that validated his hypotheses, using studies
designed around a predetermined outcome, frequently based on circular reasoning.
Is It Science, Politics or Religion?
Global warming became a religion. Religion is based on a
belief that cannot be verified by the average person, based on testimony by a
select group of priests and prophets. Heterodox opinions and evidence are
condemned as heresy, and those who voice them are shunned, ostracized and
subject to derision. Voice any skepticism to global warming in a public forum,
and observe the hysterical condemnation of your skepticism, based on the
Orthodox Scripture of global warming, quoted by people who are essentially
scientifically illiterate and incapable of understanding the underlying science
of climatology, let alone capable of seeing the holes in the theory.
The foundation of the climate change theory is based on data
that suggests a general worldwide warming trend. There's considerable
controversy as to whether this warming trend is unusual in the long-term,
whether it’s an artifact of the data collection methods, whether the data has
been manipulated to demonstrate a foregone conclusion, or even whether the data
collected is reliable, given the advances in data collection technology that
have occurred over the period in question. I don’t propose to answer any of
these questions here. Global temperatures may indeed be rising. The fact is
that global temperatures have never been constant throughout the geologic history
of the planet.
The foundation of the Anthropogenic Global Warming (AGW) theory
is based on data that shows a correlation between atmospheric CO2 levels and
global temperatures. The assumption is that CO2 is a greenhouse gas, and that
CO2 levels drive planet surface temperatures. Any scientist worthy of the name
knows that correlation is not necessarily causation. I aim to show here that
changing CO2 levels at the current concentrations have absolutely no effect on
the atmospheric energy budget of planet Earth. I will demonstrate that while
CO2 is a minor greenhouse gas, it has already made its full contribution to the
temperature of the Earth, and that additional CO2 will have no effect.
The Electromagnetic Spectrum and a Primer on Heat
The study of electromagnetic theory has some fascinating
applications. Climate change argument aside, you’re about to learn some really
interesting stuff.
Electromagnetic waves consist of an electric field and a
magnetic field 90° to each other. These waves vary in frequency, from very low
frequency waves that take tens of seconds to pass by all the way up to x-ray
and gamma ray radiation. Electromagnetic frequencies are measured in hertz. One
hertz means one wave per second. We’re familiar with radio waves in the megahertz
region that we listen to in our cars. Radars operate in the low gigahertz
region, what we call microwaves. Infrared energy we feel as heat. Our eyes are
sensitive to a certain band of electromagnetic radiation we call light. Above
that you have ultraviolet, x-rays and gamma rays.
The chart above shows the electromagnetic spectrum in terms
of wavelength. It’s backwards to what I’m used to, because I work with
frequencies, which are the inverse of wavelength. Most infrared studies deal
with wavelengths instead of frequencies, so we’ll use that.
In the year 1900 physicist Max Planck pioneered a study of
electromagnetic radiation which demonstrated that any body with the temperature
above absolute zero radiated electromagnetic fields. Planck’s formulas showed
that the higher the temperature of the body, the higher peak frequency of field
it emitted. He postulated an ideal black body radiator, which is a model to
approximate the radiation of anything with a temperature above absolute zero.
The chart above shows the electromagnetic spectrum emitted
by two different bodies according to Planck’s law, one shown in blue with a
temperature of 288° Kelvin (15°C), and another shown in red with a temperature
of 5855° K (5082°C). Why I chose these temperatures will become apparent in a
moment. You can see that the peak emission frequency shifts to the left as the
temperature goes up. Note that both axes are plotted on a logarithmic scale,
i.e. every unit is 10 times bigger than the unit before. This is common in studying
electromagnetics, because the behavior of electromagnetic waves is rarely
linear.
This chart means nothing at first glance, so let’s impose
something we all understand over the chart.
The green lines show the frequency of the visible light
spectrum. What our eyes see as blue would be on the left-hand green line, and
red on the right. You can see this effect in real life on your electric stove.
As the temperature of the stove increases, the frequency of the electromagnetic
infrared (IR) radiation shifts to shorter and shorter wavelengths (higher and
higher frequencies). As some of the energy starts to appear in the 0.38µm
region, the stove begins to glow red. This is the part of the electromagnetic
spectrum that we can detect with our eyes. As the stove gets hotter and hotter
emissions shift further and further into the visible spectrum. Around 5000°C we
see the body glowing white-hot. This is the area where the electromagnetic
emissions caused by the temperature of the body are right in the middle of our
visual detection band. If we continue to raise the temperature (a very
difficult thing to do), the white will begin to turn to blue, and theoretically
the intensity we see will begin to level out as the temperature goes up and the
emissions are pushed into the ultraviolet spectrum that we can no longer see.
I chose to show the temperature of these two bodies because
they represent the temperatures of the surface of the Earth and the surface of
the sun. We see the sun as a white light in the sky because the frequency of
its heat emissions is centered on the detection range of our eyes. This, of
course, is because our eyes evolved under this sun to gather the optimum amount
of light available. Note that while the temperature of the Earth causes it to emit
electromagnetic radiation, it’s at such a low level and a low-frequency that
it’s below our visual acuity.
The color of the sun is based on its surface temperature.
But if we’re talking about how much of that temperature is associated with
warming the Earth , we have to correct for how much energy is actually hitting
the upper atmosphere of the Earth due to distance. Correcting for distance
gives us the curve in blue below. Remember, this is a logarithmic vertical
scale, so the difference is about 1/100,000 of the sun’s surface energy hitting
the Earth.
This is an important concept to understand. The solar
radiation which warms the Earth is at a different frequency than the infrared
(heat) energy emitted by the Earth. When the solar energy, which is at a high
frequency and high energy state, strikes an opaque object, it’s absorbed by
that object. The object is excited to a higher energy state, and reradiates the
energy as infrared energy based on its own thermal curve. Typically we can
expect an object on the surface of the Earth to absorb solar energy at about
the 0.5µm wavelength, and reradiate it at about 10µm wavelength. What you’re
feeling as heat from direct sunlight is not the sunlight at all, but the
reaction of your skin absorbing that sunlight and reradiating it at a lower IR
frequency. The hot air you feel on a sunny day has been heated by conductive
transfer. The air is in contact with the surface of the Earth and is heated
through conductive contact. Sunlight has very little effect on heating the air
directly, because the atmosphere is mostly transparent at the frequencies in
which the sun radiates. The solar radiation passes right through the atmosphere
with little interaction.
An interesting side note to this is that photosynthesizing
plants are cooler in sunlight than inert materials, because the solar energy
absorbed is used to perform the photosynthesis chemical reaction, and is
therefore not reradiated. Photosynthesis uses CO2 and water to create complex
sugars, effectively storing the solar radiation in a molecular bond, and giving
off oxygen as a byproduct. When plant material is burned in a fire, or if it’s
compressed over ages into coal and oil which is then burned, the solar energy
stored in the sugars is released. To this effect, essentially all fossil fuels
are ultimately solar energy. When you drive your car down the road, you’re
releasing solar energy that hit the planet millions of years ago. Even nuclear
fuels are solar energy, stored atomic power created in the supernova of a
long-dead star before our sun was born.
Greenhouse Gas
CO2 is one of several different types of greenhouse gases in
our atmosphere. What this means is that CO2 absorbs infrared radiation emitted
by the Earth’s surface, which then heats up the CO2. As a byproduct of the CO2
heating, it also emits infrared radiation.
As the Earth’s surface absorbs sunlight, it heats up,
causing it to emit infrared radiation. If there were no greenhouse gases in the
atmosphere, most of the heat would be radiated back into outer space, and the
surface of the Earth would be much cooler than it is now. A key point to
remember is that in a thermally stable condition, the amount of energy radiated
from the Earth must be equal to that absorbed by the Earth. If the Earth
radiates more energy than it absorbs, it cools, if it radiates less, it heats
up. Greenhouse gases in the atmosphere,
including water vapor, methane, CO2 and even oxygen, absorb some of the
infrared radiation from the Earth’s surface and inhibit it from radiating back
into space.
When we’re discussing thermal transfer, we have to
differentiate between conductive and radiative heating and cooling. Conductive
temperature change occurs between objects that are in contact with one another.
If there’s a temperature difference, heat energy will naturally flow from the
hotter object to the cooler object. This conductive transfer also applies to
gases and liquids. The warm air on a hot summer day didn’t get that way because
of sunshine, which mostly passes through the air without interacting with it,
but was warmed through contact with the surface of the Earth , which was heated
up by absorbing the sunlight energy. Warm air then rises because it’s less
dense than cool air, creating convective currents and transporting heat energy
higher into the atmosphere than would be the case if the air was motionless. We
preserve temperatures in a thermos bottle by surrounding them with a volume of
vacuum, thereby eliminating the contact needed for conductive transfer.
Radiative transfer is the emission of electromagnetic
energy, which, when absorbed by another object, heats that object. Objects that
are at a higher temperature than their surroundings emit electromagnetic energy
in the infrared spectrum. This is why the inside of our vacuum bottles are
mirrored, to reflect infrared energy and prevent it from transferring even through
the vacuum of the bottle. When discussing atmospheric warming, one has to be
very careful to understand the conductive component of that warming versus the
radiative component.
CO2 is a particularly effective greenhouse gas, as it makes
up an almost insignificant part of our atmosphere. At 400 parts per million
(ppm), it comprises 0.04% of the atmosphere, yet it’s responsible for more than
2.8% of greenhouse gas warming. The Earth emits infrared energy from a
wavelength of about 4µm to 40µm. CO2 is transparent at most wavelengths, and
doesn’t interact with infrared radiation at all. CO2 does absorb infrared
energy from the wavelength of about 14.5µm to 15.5µm, and does so very
efficiently. This warms the CO2 gas, which then warms the atmosphere through
conductive heating.
Computer Modeling
Climate is a chaotic system. Small changes of input
parameters can result in large changes in the final state. Computer models are
designed to mimic climatic conditions, to predict climatic trends and to make
“what if?” extrapolations. Of course, the earliest computer models were
woefully inadequate in predictive ability, because of the vast number of
contributing factors and feedback loops in a climatic system that had to be
modeled by the computer. As computer models became more sophisticated, the
outputs more closely resembled actual observation. Nevertheless, it needs to be
understood that a computer model is a simulation of climate, using assumptions
and algorithms designed to produce an output that matches observations. The
assumptions and algorithms are adequate to approximate current climate
observations, but one has to be cautious in assuming that a change of input
conditions on the model will yield the same results as the same conditions
changing in the real climate system.
To model the effect of CO2 on global temperatures, the
computer models needed to simplify the effects of the chaos by using the value
of a forcing factor for CO2 to apply to their equations. Using temperature
measurements from the beginning of the industrial revolution to the present
day, they derived a multiplier to apply to their equations that resulted in a
close match to the observed data. The
problem is that they assumed that all of the temperature change in that time
was due to CO2 changes, completely ignoring other factors, such as changes in
solar output or levels of other greenhouse gases. This is the logical fallacy
of begging the question. The conclusion that CO2 changes drive global
temperature changes is “proven” by equations that assume that measured
temperature changes are caused by CO2 changes.
One of the assumptions made in the climate models is the
contribution of CO2. The 0.04% of CO2 in our atmosphere contributes 2.8% or
more of greenhouse gas warming. Without fully understanding the spectral
characteristics of the CO2 contribution, it’s reasonable to assume that
doubling the amount of CO2 to 0.08% would cause CO2 to contribute 5.6% or more
of greenhouse gas warming. The disproportionate amount of CO2 contributions to
greenhouse gas warming to the trace amounts of CO2 in the atmosphere is
staggering.
This assumption seems to be corroborated by atmospheric
analysis of ice core samples taken from Greenland and Antarctica. Based on the
assumption that global temperature is directly affected by changes of CO2 in
the atmosphere, one can analyze the ice core data and see a correlation between
global temperatures and CO2 levels. This seems to confirm the hypothesis that a
greater amount of CO2 will contribute more to greenhouse gas warming. One would
not expect a climatologist to necessarily have a conversant knowledge in
chemical spectral absorption properties, or be able to do gain and loss
calculations in the electromagnetic spectrum. Without a thorough understanding
of these, incorrect assumptions about how CO2 works as a greenhouse gas can be
reasonably expected.
Absorption Spectrum
In the year 1802 English chemist and physicist William
Wollaston past sunlight through a very narrow slit onto a prism. This broke the
sunlight up in the spectrum which he was able to view in detail on a wall 12
feet away. He was able to see a spectrum running from red, yellow, green, blue
to violet. He also reported seven dark lines in the spectrum. At certain
frequencies the sunlight seemed to be getting absorbed. Wollaston had no
explanation for this. Twelve years later Joseph von Fraunhofer, using a much more
sensitive method, mapped out 574 thin black lines in the visible band of the
solar spectrum.
In 1826 John Herschel showed that when a substance is heated
in the light pass through a spectroscope each element gave off a
characteristics set of bright lines of colors.
In 1849 Jean Foucault showed that the emissions lines given
off by an element when heated lined up aligned perfectly with some of the
absorption lines identified by Wollaston.
In 1862 Anders Jonas Ångström isolated four lines in the
visible portion of the hydrogen emission spectrum, and they were later shown to
match the dark lines that appeared when light was passed through a hydrogen gas
sample and then refracted into a spectrum, confirming Foucault’s work.
Today we understand that these thin lines of absorptivity
are as characteristic as fingerprints for identifying different molecules.
These discoveries led to important advances in chemistry, understanding the
atom, quantum physics and astronomy.
The CO2 Absorption Spectrum
The flaw in climatologist computer model assumptions about
CO2 is that they assume that the absorptive capability of CO2 will increase
proportionally to the amount of CO2 in the system. This is because they don’t
consider the spectral characteristics of CO2 electromagnetic absorption.
We can see the CO2 absorption characteristics from the
NISTwebsite. To view this in context of my discussion here, change the
graph settings to normal X,µm and transmittance.
So what we see here is an area of high absorption at about
4.2µm, which is near the very high-frequency end of the Earth’s infrared
emissions. And then a much wider area of absorption from about 14.5 to 15.5µm.
The two artifacts just below 14µm in just above 16µm appear by their symmetry
to be heterodyne products caused by a preamplifier without a preselector in
the measurement equipment, and are not real measurements.
Let’s plot this on the graph we’ve been looking at before:
You can see the two CO2 absorption bands here in violet, the
primary band being well outside of the infrared contribution from the sun.
It’s of particular importance for us to understand what
exactly is being measured in the NIST graph. This graph was achieved by
analyzing the spectrum of light passed through a 10 cm path of one part CO2
mixed with two parts N2 (nitrogen), at a pressure of 600 mmHg (1 atmosphere
equals 760 mmHg).
We see from the NIST data that at about 15µm, only about 30%
of the IR energy is getting through. In the electromagnetic realm we measure
change the power in decibels (dB). A 70% loss of energy equates to about a 5 dB
drop in power. From this, we can say that we have a 5 dB loss in a 10 cm path
where the CO2 concentration is 333,333 ppm.
We can use the Beer Lambert law, A=Єbc, to calculate the
needed path to get 5 dB’s of loss at the current atmospheric concentration of
CO2 of 400 ppm; where A is the optical density, Є is the absorptivity, b is the
path length and c is the concentration. Optical density and absorptivity are constant,
so the path length and the concentration are inversely proportional. Using a
concentration of 400 ppm, we calculate the necessary path length to be 83.333m
(273.4 feet) for a five dB drop in power at 15µm.
If we double the path length to 166.66 m, we get a convenient 10 dB drop in power.
Electromagnetic engineers love working in increments of 3 dB and 10 dB, because
it makes the calculations simple. The 10 dB drop in power means you have 1/10
th
of the power after the drop that you had before. The 20 dB drop in power
equates to 1/100 of the power. A 30 dB drop means 1/1000 of the power. To get a
30 dB drop in the available electromagnetic energy at 15µm due to CO2 at
roughly 1
atmosphere, your path would only have to be 500m (1640 feet) long. That’s
way less distance than the IR radiation from the Earth has to travel to be
radiated into space.
The
two primary absorptivity bands of CO2 lie in the infrared spectrum, well below
that of visible light. We therefore cannot “see” these bands in a refracted
spectrum without specialized equipment for detecting infrared. If we could see
these with our eyes, we would see the refracted spectrum would have a black
line at the point the represented the 14.5 to 15.5µm band. If we were in outer
space looking at the infrared emissions from the Earth and running them through
a prism, we would detect nothing between 14.5µm and 15.5µm. The infrared energy
between those two wavelengths has been attenuated away to nothing. The energy
has gone to heating up the CO2 which absorbed it, which then conductively
heated up the surrounding atmosphere.
Proponents
of the CO2-based global warming model point out that when you heat up the
atmosphere, it produces infrared radiation itself, in the same bands as it was
absorbed, according to Foucault. They use this to propose some sort of amplification mechanism
wherein the infrared gets absorbed and re-emitted over and over, cumulatively
contributing to atmospheric warming, reflecting back to the Earth and causing
it to heat even more. This simplistic understanding ignores the laws of
thermodynamics and the fact that the Earth/atmosphere temperature has already
reached equilibrium with respect to the greenhouse gas contribution. CO2 will
not radiate more infrared energy than it absorbs if it’s at the same
temperature as its surroundings. It also ignores the fact that the “passing
along” of photons in the direction of propagation has already been accounted
for in the loss measurements such as NIST performed, and the result is still an
opaque gas at those frequencies.
Given
that the Earth’s radiation temperature in the infrared region is more or less
fixed, adding more CO2 will not increase the atmospheric temperature in the
slightest. All the available energy in the 14.5µm to 15.5µm region has already
been absorbed and contributed to heating the atmosphere. The Earth’s atmosphere
is effectively 100% opaque at these wavelengths. You cannot get additional
energy out of the system without adding energy to it somehow. The only way that
adding CO2 to the system would increase the amounts of greenhouse warming
contributed by CO2 is if the initial CO2 concentration was low enough that a
measurable amount of infrared radiation between 14.5µm and 15.5µm was already
escaping into space, i.e. where the atmospheric opacity was less than 100%, and
adding additional CO2 would increase the opacity. CO2 levels low enough for
this to be the case would be too low to sustain life on planet Earth. You
simply cannot become more opaque than 100%.
What
would be the effect of increasing the CO2 levels? We’ve already seen the linear
correlation between CO2 concentrations and the path distance necessary to
completely absorb the available energy at the absorption wavelengths.
Increasing CO2 concentrations will shorten that path. Effectively, this would
mean that the greenhouse effect of CO2 will be concentrated at lower altitudes.
The overall average temperature of a column of air will be unchanged, and any
concentration of heat closer to the ground will likely be offset by convection
because warmer air rises. This could have implications near the ocean of
increasing evaporation, which in turn will
increase
convection because moist air is lighter and tends to rise. Since the CO2
contribution to global warming is less at higher altitudes when CO2 is in
higher concentrations, moist convective air currents will encounter colder
temperatures at lower altitudes and condense into clouds, further cooling the
atmosphere through condensation and increasing the reflective surface albedo of
the planet. This is a prime example of thermal feedback cycles inherent in
climate science.
The Climate Record
But
what of the ice core samples that show a direct correlation between CO2 levels
in global temperatures? AGW advocates point at this as
the smoking gun that CO2 drives global temperatures. The evidence seems to fit
their understanding, where additional CO2 results in higher temperatures.
The
ice core sample data seem to confirm the CO2 warming hypothesis, and no further
investigation was needed. What these graphs show that isn’t explained by the
CO2 warming hypothesis is why atmospheric temperatures began to fall while CO2
levels were still relatively high. CO2 levels and atmospheric temperatures seem
to rise in lockstep, but CO2 levels lag declining atmospheric temperatures.
To
answer this we have to consider Henry’s Law, formulated by William Henry
in 1803 which states: "At a constant temperature, the amount of a given
gas that dissolves in a given type and volume of liquid is directly
proportional to the partial pressure of that gas in equilibrium with that
liquid." The key to this is constant temperature. The solubility of the
gas and liquid solvent decreases as temperature increases. The oceans of the
Earth are considered to have 10 times more dissolved CO2 than is contained in
the atmosphere. If the temperature of the oceans increase, the amount of CO2
that they can hold in solution decreases, and the oceans must outgas the excess
CO2, much the same as a bottle of soda does when you release pressure. There is
no delay, and no appeal. Excess CO2 is released immediately. Conversely, when
temperatures fall there is no mechanism that requires atmospheric CO2 to
immediately be dissolved in the ocean. This is a slower process as the partial
pressures between the CO2 in the atmosphere and the CO2 stored in the ocean
slowly equalize. If our hypothesis is that ocean temperatures are directly
responsible for atmospheric temperatures and CO2 levels, we would expect
atmospheric temperatures and CO2 levels to rise simultaneously, and for CO2
levels to lag declining atmospheric temperatures. This is exactly what the data
shows us.
Greenhouse Gases in General
CO2 gets a lot of attention from climatologists because of
its disproportionate contribution as a greenhouse gas compared to its almost
insignificant presence in the atmosphere. But it’s by no means the greatest
contributor to the greenhouse gas effect. Water vapor is also a greenhouse gas.
While it’s not nearly as efficient as CO2 and absorbing IR energy at any
specific wavelength, it’s far more abundant than CO2 on average. Unlike CO2,
it’s not 100% opaque at its absorption wavelengths, so increasing water vapor
will result in a corresponding increase in atmospheric temperatures. Water vapor has some other important differences. Where CO2 is relatively evenly
mixed throughout the atmosphere, water vapor levels vary dramatically as result
of temperature and pressure differentials. Water vapor is virtually nonexistent
at temperatures below freezing, and at common temperature/pressure
combinations, it condenses and blocks visible sunlight from reaching the ground
(clouds). The combination of opacity and reflectance of condensed water vapor
is a major factor in cooling parts of the planet.
Here’s an experiment for you to do. On a typical summer day
spend an evening in Charleston, South Carolina. You’ll typically notice high
humidity, and when the sun goes down the temperature doesn’t change very much,
it stays warm and muggy. Now take a trip out west to Tucson, Arizona. Same
latitude, same amount of sunshine as Charleston gets. Same amount of CO2,
generally speaking, but normally vastly less water vapor. Notice that the
summer day in Tucson is much hotter than in Charleston. There is little water
vapor interfering with sunlight striking the ground, heating it almost to
oven-like temperatures. But the interesting thing is what happens when the sun
goes down. Bring a coat, because even on a summer night it’s likely to get cold
in Tucson. All that CO2 in the atmosphere doesn’t do a darn thing for keeping
the air warm. The heat radiating from the Earth radiates right through the bulk
of the atmosphere without inhibition, and is lost to space.
In the graph below you can see the contributions of water
and CO2. But this graph doesn’t show you is that the third water vapor profile
varies dramatically from place to place due to differences in humidity. The CO2
graph is relatively constant worldwide, and is plainly saturated. Adding more CO2 to the
system will not result in any less energy being radiated into space at those
frequencies.
Response to Criticisms
My approach to explaining this through the eyes of an
electromagnetic engineer is unique, but the basic concept that the CO2
absorption band is saturated isn’t. Many
other AGW critics have come to the same conclusion, and of course the members
of the church of AGW have developed a doctrine to answer these criticisms. One of these answers states, “Any saturation
at lower levels would not change this, since it is the layers from which
radiation does escape that determine the planet’s heat balance. The basic logic
was neatly explained by John Tyndall back in 1862: "As a dam built across
a river causes a local deepening of the stream, so our atmosphere, thrown as a
barrier across the terrestrial [infrared] rays, produces a local heightening of
the temperature at the Earth’s surface."”
Well, that’s an interesting and actually an apt analogy. The problem is with the assumption that CO2
is like a dam built across the stream. It’s not, because for most of the spectrum, CO2 doesn’t inhibit the
stream at all. CO2 is more like a post
in the middle of the stream. The water
rises slightly to either side of it, because it does change the cross-section
of the channel, but essentially flows around it. Make that post as tall as you want, once it
breaks the surface of the water, it can’t block any more than it already does.
The other misstatement in this argument is that, “... it is the layers from which
radiation does escape that determine the planet’s heat balance.” This is incorrect. The temperature of the upper layers of the
atmosphere has no effect on the IR radiation if that atmosphere is transparent
to the IR radiation. If the
transmissivity of the atmosphere is at or near one, the IR radiation will
simply pass through it with no interaction. If it were otherwise, then IR radiation simply wouldn’t propagate
through the atmosphere at all. Since there is little to no water vapor at high
altitudes where the atmospheric temperature are claimed to be a factor, the
atmosphere is completely transparent to IR radiation across most of the
spectrum.
Remember, it’s about heat balance. The
energy in the CO2 absorption band is dissipated in the first few hundred meters
of atmosphere above the earth, and finds its way back to the surface. Once the system is reached equilibrium, the
surface of the Earth is radiating at a higher average temperature than it would
be if there was no CO2. That energy is across the IR spectrum, most
of which either radiates to space without any interference from CO2, or is
absorbed by other greenhouse gases. Think of our post in the middle of the stream. Same amount of energy gets into space, but at
a slightly higher overall temperature, since it can’t radiate in the 14.5µm to
15.5µm band.
The other argument is that the CO2 bandpass is not constant,
that adding more CO2 gets deeper into what we in the electromagnetics industry
call the filter skirts, effectively increasing the bandwidth of
absorption. This graphic is trotted out
to demonstrate:
Of course, to most people, this graphic
looks pretty impressive. Whoa! As we get
more CO2, the bandpass gets wider, and we get more absorption! It never ends! Hold on a second, Hoss. Pay attention to the vertical scale. That’s a logarithmic scale, which means that every
major unit is 10 times smaller than the one above it. There’s really no way to
explain this if you’re not already familiar and comfortable with working
logarithmically, so it’s easier just to show you.
I don’t have access to the data set they used to generate
the lovely graphic above, but I do have the NIST data for the same region, so
let’s use that. Using NIST’s data,
here’s a similar graph to the one you see above. The area inside the red lines is currently
saturated at present CO2 levels.
Now, the argument goes that the more CO2 you add to the
system, the further down those skirts we’re going to be saturating, which means
we’re going to be absorbing more and more energy, the more CO2 we add. The claim is that no matter how much CO2 you
add, there will always be more bandwidth being saturated, so you can never
encounter a condition where adding more CO2 won’t absorb any more IR
energy. The graph certainly does suggest
that.
But wait. The amount of energy able to
be absorbed by CO2 is basically equal to the area under the curve (remember
basic calculus?). If you’re going to do
that, you don’t use a log scale, you use a linear scale, like this:
Exact same data. The
only difference is the Y axis is plotted linearly, instead of logarithmically. Note the present CO2 levels saturate the bulk
of the bandpass. Adding more CO2 will
push the curve upward. Saturation (the
point at which no IR radiation escapes to space at the current Earth
temperature) happens at about 290 on this chart. The amount of extra
absorptivity you get from the wider skirts is insignificant. Adding more CO2 is
not going to significantly change how much heat is trapped.
AGW advocates claim that adding CO2 will drive the heat absorption to lower
altitudes, resulting in more heat closer to the surface, increased evaporation
from the oceans, and thus compounds the problem by increasing water vapor in
the atmosphere, which is another and arguably more significant greenhouse
gas. Yes, more CO2 will cause the heat to
be trapped at lower altitudes, but this argument breaks apart very quickly,
because warm air rises. Even if we
assume a higher water vapor load to this rising air, it encounters cold air at
lower altitudes, and the water vapor condenses to clouds, which cool the planet
by reflecting a large chunk of sunlight back into space.
Conclusion
The Earth may or may not be experiencing global warming or
climate change. One can reasonably argue that the Earth is constantly
experiencing climate change. It’s nothing new. A variety of things may
influence global temperatures, the strength of sunlight hitting the Earth ,
volcanic action, methane levels or pollutants and aerosols in the atmosphere.
One thing that is certainly not affecting global temperatures is variations in
CO2 levels. The CO2 absorption wavelengths stop absorbing linearly at
concentrations of less than 1/10 of what’s currently in the atmosphere. Anyone
who tries to say different needs to explain where the extra energy comes from
in the 14.5µm to 15.5µm band.
Computer climate models need to be adjusted to reflect that
CO2 does not act like water vapor. Above about 40 ppm, varying CO2
concentrations has little to no effect on CO2’s greenhouse contribution,
because it is already absorbed all of the available IR energy in its absorption
spectrum. Computer climate models also need to address gases in solution in the
ocean at varying temperatures.
The climate models make the case that the effect of CO2 is
based not only on the proximate warming of CO2, but also the feedback
mechanisms, primary of which is an increased rate of evaporation of the ocean
due to higher temperatures. Since water vapor is in itself a greenhouse gas,
this evaporation is supposed to amplify the effects of additional CO2. The
amplification factor is generally agreed to be three times that of warming
attributable to CO2 by itself. This number is derived by the assumption that
all of the observed warming in the 20
th century was a result of CO2
increases. This is an absurd assumption in the system as chaotic and complex as
climate. The problem with this model is that it suggests a climate “tipping
point,” which would result in runaway heating, and ignores dampening feedbacks
which would tend to keep climate stable. Since in geologic history there have
been times when CO2 is been many times greater than it is today, and yet no
runaway condition has ever been reached, we can assume that degenerative
feedback loops exist that keep global temperatures from deviating too far from
the mean. The Earth is currently in a period of glaciation, and we have been
privileged that our civilization has risen during one of the interglacial warm
periods. The general long-term trend of the Earth’s climate is one of cooling,
and this is in line with the solar output which is the ultimate source of all
heat energy on earth. (Climate change in
12 minutes, the skeptics case).
