At his September 24 speech before the UN General Assembly, President Trump called climate change “the greatest con job ever perpetrated” and added that “the carbon footprint is a hoax made up by people with evil intentions.” I agree with him on both counts, but will address only the science, relying on an exhaustive survey and synthesis of the scientific literature by Robert Ian Holmes and Brendan Godwin in their book, Climate Truths, Science the IPCC Rejects. This is far and away the most comprehensive presentation of what the scientific literature says about all the competing hypotheses. The authors’ overall conclusion is that more CO2 – only about 4% of which is generated by human activity – has virtually no effect on atmospheric warming. Nonetheless, the authors are careful to present and address fully and fairly arguments supporting the propositions that (1) CO2 drives temperature change, (2) CO2 generated by human activity is a primary driver of rising temperatures and (3) those effects are are harmful.

Headline Conclusions

1. Not ONE of the more than 30,000 published papers in the empirical literature quantifying tropospheric warming attributes it to the atmospheric concentration of CO2. No one has ever measured warming from CO2.

2. The variation in atmospheric temperature runs in natural climate cycles and is entirely due to natural causes. The important of these are:

a. Atmospheric pressure. Gravity acts on the mass of the atmosphere, causing it to compress itself, thereby increasing its density and internal pressure. Greater density and pressure necessarily mean higher temperature and vice versa. This relationship explains why temperature drops with an increase in altitude, and air feels cool when being let out of a tire.
b. Convection, the transfer of heat, i.e., energy, within the atmosphere caused by internal differences in its density and pressure. Convection flows go from warmer areas to cooler areas
c. The activity of the Sun. the Sun causes variations in the temperature of the Earth’s surface mainly via flux in its cosmic rays (CRF) which in turn hugely affects the rate of cloud formation. More cloud cover means less sunlight hitting the Earth and therefore lower temperatures.

3. There is no such thing as a greenhouse effect (GHE). The essential claim of climate alarmists is that the Earth’s atmosphere acts like the roof on a greenhouse. Their theory is that just as the greenhouse glass traps incoming infrared radiation (IR), causing the inside temperature to rise, so do CO2 molecules trap IR streaming into the atmosphere. Their hypothesis is disconfirmed by observation. Experiments repeated many times, always with the same result, show that the temperature of an enclosure covered by a material that enables IR to escape, i.e., is transparent to IR, is about the same as the temperature of an enclosure that traps IR, i.e., absorbs it. What accounts for almost all the heat within a greenhouse is not IR, but the blockage of convection by its roof. Earth’s atmosphere does not have a roof.

4. Since:
a. 71% of the Earth’s surface is covered by oceans
b. oceans control atmospheric temperatures,
c. water is almost opaque to the frequency (~ 15 micrometers) of back radiation from CO2 molecules),
it is impossible for CO2 to be a control knob for atmospheric temperature.

5. The atmospheric concentration of CO2 increases after the temperature increases. Something that comes after something can’t cause it. On long time scales, CO2 lags temperature by an average of 800 years. Over short time scales it lags temperature by about 10 months. This occurs because the ability of the ocean to absorb CO2 varies inversely with temperature. As the oceans warm, they “outgas” CO2 to the atmosphere.

6. Even if CO2 did have an impact on surface temperature, a doubling of its concentration to over 800 ppm (parts per million) would have an unnoticeable effect on temperature. (See my article https://truthornonsense.com/why-co2-emissions-are-not-a-problem-now-and-never-will-be/on why this is so.)

Responses to Purported “Knockdown” Claims in Support of Climate Alarmism

1. The Sun cannot be a significant cause of recent warming. Recent changes in total solar irradiance (TSI) are only 0.01%, a variation too small to have accounted for the 0.8⁰C of warming since the end of the Little Ice Age (LIA) in 1750.
The premise is wrong. In the abstract oof the paper referenced below, the authors stated that”A critical flaw flaw emerges in the IPCC’s reliance on a single, low variability Total Solar Irradiance (TSI) reconstruction, despite the existence of 27 viable alternatives, where the higher-variability options align closely with observed warming – itself exaggerated by data adjustments.”
https://scienceofclimatechange.org/wp-content/uploads/SCC-Grok-3-Review-V5-1.pdf

2. President Obama told us that 97% of scientists agree that human activity is contributing to global warming.
His statement is incorrect.
• For example, over 31,000 scientists, including 9,000 Ph.D.s, signed the Oregon Petition Project, stating that the IPCC reports ignore the huge volume of scientific papers, supporting the conclusion that climate change is due to variability in natural climate cycles. A bachelor’s degree in a relevant science was a prerequisite for eligibility as a signatory.
• Other organizations of scientists declaring that there is no climate emergency include

https://clintel.org/,
https://climatechangereconsidered.org/about-the-nipcc/,
https://co2coalition.org/.

3. Human generated CO2 remains in the atmosphere for thousands of years; its cumulative effect inevitably leads to warming.
This claim is disconfirmed by scientific inquiry. Human emissions stay in the atmosphere only around five years (Climate Truths, p. 172).

4. Current warming is unprecedented.
Wrong. It was warmer during the Minoan warming (1450-1100 BC), the Roman Warming (250-BC – 400-500 AD, and the medieval warming (900-1300AD when wine was grown in Greenland.
The whole climate alarmism narrative is in tatters and needs to be discarded so that the waste of further trillions of dollars on a non-problem is avoided.

[1] Robert Ian Holmes & Brendan Godwin, Climate Truths, Science the IPCC Rejects, McPherson’s Australia, May 2025, 442 pages. Page numbers in my essay refer to pages in the paperback version of the book.