The Rice Video – Carbon Dioxide in Perspective: Is There a Grain of Truth in What Roberts Has to Say?

When I was directed by an email link to this video ( I thought I had been sneakily misdirected to a televangelist’s video – he looked just like your common or garden mercenary TV pastor/charlatan.

I must admit that I did not get past the first minute of his presentation when his earnest piercing eyes forced me to shut him down before I did the coyote trick and chewed my arm off.  So, this will not be a comprehensive refutation of his claims but I got enough of his drift and arguments early on and I did not wish to waste my life any further than I had to.  It’s all been said before.

I am always suspicious of people who trot out a lot of career descriptors.  Malcolm Roberts has a particularly impressive list but only the BE could be relevant as I presume it stands for Bachelor of Engineering.  The MBA is meaningless in this context and the rest of the descriptors are merely paid for memberships of irrelevant societies and associations*. 

FAICD – Fellow of the Australian Institute of Company Directors

ASQ – American Society for Quality

MAusIMM – Member of the Australasian Institute of Mining & Metallurgy

MAIM – couldn’t find this one

SME (USA) – ditto

MIMM (UK) – Member of the Institute of Mining & Metallurgy, UK

AME (USA) – possibly

These qualifications are pretty underwhelming, then again who am I to diss him as I only have a B Sc (Mech Eng) and I never ever paid any subscriptions to any society or association.  I have been practicing social distancing my whole life (and have just become relevant with Covid-19) but I also use the Groucho Marx defence that “I refuse to join any club that would have me for a member.”

* Joel Mervis wrote the fun column, The Passing Show, for decades in the Sunday Times and always used to sign off after his name with MAHFGR – May All His Finesses Go Right

Claim: Manmade CO2 Is Negligible

He claims that only 3% of annual CO2 production is due to manmade origins and therefore is insignificant.  I have 2 arguments to counter that without delving into the origin of that statistic.

  1. The first argument is completely non-scientific but uses an analogy that the lay man can understand how something non-obvious can occur.  The average person eats roughly 500g of food per day.  If one consistently had 1 teaspoon (4g) of sugar more than the body required, after a year, one would have had 1.5kg excess sugar which would have translated into roughly an equivalent weight increase.  That’s all it takes after a complex process of digestion, basal metabolism, burning off due to exercise and voiding for any consistent imbalance to result in a weight increase.  After a lifetime of doing this the results would be too horrendous to contemplate.
  2. The historical record of CO2 suggests that atmospheric CO2 has varied between 190ppm and 290ppm with the interval between a min and a max being about 100,000 years.  However, over only the 200 years from 1800, the CO2 levels have increased from about 270 to 380ppm.  All that I can say is that that measly little 3% anthropomorphic contribution that he talks about is really being overworked and should complain to its union.  Someone’s lying here – either all the reputable scientific organisations or this earnest misguided pillock or perhaps its just that spoonful of sugar.

Although I did not watch the video much further, normally the argument continues in the vein that how can such little CO2, <400ppm or <0.04%, cause global warming.

How does CO2 provide a thermal blanket?

Let’s backtrack a little.  Light is part of the electromagnetic spectrum and the sunlight light that we receive corresponds to a temperature of roughly 5600K.  The bulk of this energy is in the visible spectrum with lesser amounts in the UV (higher frequency) and infrared (lower frequency).  The atmosphere generally propagates the electromagnetic spectrum well but has well defined absorption frequency bands.  These absorption bands occur when the frequency of the light corresponds to a resonance frequency of the various gas molecules that comprise our atmosphere.  The radiation at these frequencies, on striking the molecule, cause it to resonate thereby absorbing the radiation.  The majority of the light reaches the Earth’s surface which heats it up to an average of around 290K (17°C).  This lower temperature then reradiates as infrared radiation, a lot of which corresponds to the resonance frequency of CO2 molecules and other greenhouse gases such as methane.

How can so little CO2 provide a thermal blanket?

A question sometimes asked is how can such a small amount of CO2 which only comprises 0.04% of the atmosphere cause this blanketing effect?  I have two answers, the first of which is by analogy again.

  1. Proof by Analogy

The concentration of Ozone in the atmosphere is 0.3 ppm (parts per million) while that of CO2 exceeds 400ppm.  After decades of hearing about the hole in the Ozone layer and our mothers constantly telling us to wear sunscreen, people accept that this mere wisp of Ozone can block most UV from reaching the surface.  Yet at the same time some people have a problem accepting that 1300x more CO2 can prevent infrared radiation escaping from earth.

  1. Proof by Calculation

This is a simple calculation to work out how many CO2 molecules are directly above every point on earth.  It does this by considering a 1m x 1m column of the atmosphere extending from earth to space.

Mass of CO2 in the atmosphere   = 3.2×1012 ton   = 3.2×1018 g

Area of the Earth              = p d2

= p x 127002 km2

                                                = 5.1×108 km2

                                                 = 5.1×1014 m2

Therefore, the mass of C above each square metre of earth is

Mass  CO2 per m2             = 3.2×1018 g/ 5.1×1014

                                                = 6270 g

Mass of 1 mol of CO2      = 12 + 2*16

                                                = 44g

Therefore, each 44g of CO2 contains 6×1023 molecules 

Therefore, above each m2 of Earth there are

                                NCO2       = 6×1023 x 6270/44

                                                = 8.6 x 1025 molecules of CO2

Atoms are not hard spheres, and there are many methods of defining their size, but generally it is some measure that defines their area of influence.  One measure is the covalent radius of a Carbon atom alone which is 70pm (picometer or 10-12m).  To be conservative, we’ll take the diameter of CO2 to be 140pm and neglect the two oxygen molecules which would make it oblong and much bigger. 

If they were placed cheek by jowl on a 1m2 plane, there would be a grid of 1/140×10-12 (=7.1×109) atoms in a row and the same number of rows.

Therefore, there would be 5.1×1019 atoms on the plane. 

If all the CO2 molecules above that 1m2 of Earth were stacked in layers, there would be 1.7 million layers!

This demonstrates that although the CO2 is sparse, if an infrared photon is projected upward, it has a virtually 100% likelihood of hitting (or coming within the influence of) a CO2 molecule at some point on its journey and be absorbed thereby heating the atmosphere.

An Aside:  Hot objects on the surface of the earth emit their heat hemispherically.  In other words, only a small portion goes straight up in the shortest path through the atmosphere.  Most is transmitted diagonally and will hence encounter far more molecules on its path.  The above calculation is thus a simplistic but a very conservative approach and underestimates the probability of absorption by CO2.

(Note, this is not the end of the story as that molecule re-radiates energy, some into space, some laterally to other atmospheric molecules and some back to earth.  So, some does escape still.  If it did not, the Earth would have fried long ago.)

It’s Complicated

The note at the end of the last point gave a small hint as to climate science being complicated.  Actually it’s far worse.  It’s like religion – a mass of apparently contradictory points that allows for endless debates and for snake oil pastors to quote something to support themselves and make themselves relevant (and rich).  And its not only the hustlers who rely on this for their livelihood, but also serious scholars – imagine how many argumentative rabbinical scholars would become redundant if the Torah spoke plainly.

I came across an interesting graph from NASA GISS which showed just how difficult it is to predict temperature as there are many forcing functions – some that drive the temperature up and some that reduce it.  One of the biggest short term swings is caused by volcanic activity although not from the greenhouse gases they spew out which are negligible compared to man made CO2.  The aerosols that they put into the stratosphere reflect sunlight and hence cool the planet.  Their effect is however not long lasting.  Nevertheless, they can cause short term deviations in the temperature record.

The result is that it is possible to have periods when the earth cools.  However, CO2 has now become the dominate driver and temperatures have never been this high for the last 800,000 years.


A further complication to note is that the Earth receives 1350W/m2 on its outer atmosphere yet none of these drivers are more than 3W/m2 – as I said, it’s complicated.  The Earth is a finely balanced ecosystem and although there are massive variations, all it takes is for a small consistent imbalance in the heat equation to cause a long term change – much like that daily teaspoon of sugar.

The picture on the above further illustrates the complexity of the heat balance (It should be noted that I claim a solar radiation of 1350W/m2 whereas the illustration claims 341.  It is not a contradiction.  My number is for a plane perpendicular to the Earth whereas the illustration takes the 1350 and distributes it evenly over the surface, including the temporarily non-illuminated side):

As a final point, in 1912 an august authority of no less than the SA Railways noted in their magazine that the atmospheric temperatures would increase in the centuries to come due to the burning of coal.  They quoted centuries because they could not conceive the exponential growth of human consumption.  The magazine quotes an annual output of 7Gt whereas it has now reached 36Gt!

In Conclusion

I think that Malcolm Roberts – BE (Hons) 1976, UQ, MBA, 1990, Chicago, FAICD, ASQ (USA), MAusIMM, MAIM, SME (USA), MIMM (UK), AME (USA) – should take his video and shove it where the sun don’t shine.


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