Industry Expert on Carbon Dioxide Explains Why CO2 is a Harmless Gas

Written by PSI Editor on March 2, 2026. Posted in Current News

Eminent Canadian chemical engineer Dr. Pierre R. Latour explains why carbon dioxide (CO₂) does not warm the Earth in any meaningful way—and may even cause a very slight cooling.

Dr Pierre R Latour PhD PE has contributed close to 90 articles to various scholarly journals, including ‘The Four Known Scientific Ways CO2 Cools Earth’s Climate‘ published in Principia Scientific International. He is a major intellectual force in ‘slaying’ the junk greenhouse gas theory beloved by climate alarmists.

Latour is also renowned world-wide for his industry-leading achievements on chemical engineering and his understanding of the physical properties of carbon dioxide is second to none. Indeed, in 2019 Marquis Who’s Who, the world’s premier publisher of biographical profiles, presented Dr Latour with the Albert Nelson Marquis Lifetime Achievement Award.

Below is a plain-language summary of Dr Latour’s reasoning about carbon dioxide, based on known scientific data and claims in Latour’s original technical outline.

How CO₂ Interacts with Radiation

To understand Latour’s position, it helps to start with basic radiation physics.

Clouds reflect and absorb sunlight, which cools the surface below.
Carbon dioxide also absorbs certain wavelengths of sunlight, according to its absorption spectrum.
After absorbing energy, CO₂ molecules re-emit electromagnetic radiation in all directions.

This re-emission is central to what is commonly called the “greenhouse effect.” Some of the radiation emitted by CO₂ travels back toward the Earth’s surface (which is claimed to warm it), while some travels outward into space. Below is a diagram of what is generally understood of the supposed “greenhouse effect.”

Latour emphasizes that (contrary to alarmist claims):

CO₂ emits radiation in all directions, not just downward.
More than half of the radiation it emits goes back into space.
Less than half is directed toward the surface.

What the Data Shows: A Net Cooling Effect

Latour argues that when additional CO₂ is added to the atmosphere:

It absorbs some incoming sunlight, reducing the amount that reaches the surface.
It emits radiation in all directions, including downward toward the surface.
However, because more than half of that emission goes into space, the downward radiation is less than the sunlight blocked.

His conclusion is that the reduction in direct solar radiation reaching the surface outweighs the warming effect of downward CO₂ emission. Therefore, he argues, the net effect is a very slight surface cooling.

The Estimated Temperature Effect

Latour calculates that:

Adding 100 parts per million by volume (ppmv) of CO₂ to today’s level of about 400 ppmv (a 25% increase to 500 ppmv) would change surface temperature by approximately:

$CO₂-0.006^\circ C \text{ per } +100 \text{ ppmv CO₂}$

Elsewhere in his estimate, he gives a value of:

$CO₂-0.1906^\circ C \text{ per } 100 \text{ ppmv CO₂}$

In both cases, he characterizes the temperature change as negligible.

He argues that this increase of 100 ppmv would take roughly 20 years at current rates of accumulation, depending on natural plant-animal carbon balance.

Energy Balance and Radiation Physics

Latour bases his reasoning on the Stefan–Boltzmann law, which relates temperature to radiated energy:

$\sigma \varepsilon T^4$

Where:

$I$ = radiating intensity (watts per square metre)
$σ\sigma$ = universal radiation constant
$ε\varepsilon$ = emissivity (between 0 and 1)
$T$ = absolute temperature

He argues that:

As atmospheric CO₂ increases, the atmosphere radiates more energy to space.
Radiation from the surface to space decreases.
The total outgoing radiation remains equal to incoming absorbed solar energy.
The surface cools slightly, while the atmosphere warms.
Overall energy is conserved.

In his view, because the total radiation to space remains unchanged, the Earth’s global radiating temperature stays the same.

His Broader Conclusion

Latour concludes that:

CO₂’s climate impact is extremely small.
Any temperature change from increased CO₂ is either negligible or slightly cooling.
The influence of CO₂ on global climate has been overstated.
He further claims that Earth’s temperature has not increased since 1987 and that the planet is “neither too hot nor too cold.”

Sources Cited by Latour

Latour, P. R., Radiation Physics Laws Give The Effect Of CO₂ On Earth’s Temperatures – A Primer (2017)
Latour, P. R., Engineering Earth’s Thermostat with CO₂? (2010)

Final Note

The explanation above reflects Dr. Latour’s interpretation of radiation physics and climate dynamics, presented in simplified form for general readers. His central claim is that increased atmospheric CO₂ causes a very small cooling effect because more than half of the absorbed radiation is re-emitted into space.

Other relevant PSI publications by Dr Pierre R Latour PhD PE:

Skeptical Arguments that Don’t Hold Water – Pierre Latour’s Rebuttal

https://principia-scientific.com/radiation-physics-laws-give-effect-co2-earths-temperatures-primer/

https://principia-scientific.com/engineering-earth-s-thermostat-with-co2/

https://principia-scientific.com/che-models-earth-s-temperature-response-to-fuel-combustion/