Anthropogenic Carbon Dioxide lacks power to cause dangerous Global Warming

The United Nations Climate Change Conference in Paris in 2015 continued to promote the notion that emissions of Anthropogenic Carbon Dioxide (ACO2) are the single cause of progressive Global Warming. Conference called for annual ACO2 emissions to be reduced, by law, to zero over the 21st century to avoid Dangerous Global Warming.

But, there is no proven correlation between Global Warming and ACO2 emissions. It has been built on the following invalid syllogism, with no reference to water vapour -

This report provides an alternative view. It applies well-established Science of Heat Transfer within Major Gases and Vapours of the Earth's atmosphere to demonstrate that ACO2 emissions are too low to cause dangerous global warming. The importance of Carbon Dioxide (and hence ACO2) in the Greenhouse Effect has been exaggerated.

Accepted breakdown proportions of major components of the atmosphere are used. Water is exceptional because it is a vapour, and so is a significant variable in heat transfer calculations and computer models. The range for water content between Dry and Saturated is measured in terms of Relative Humidity. The report chooses to concentrate on values applying to a Temperate Climate (15oC at Sea Level with 1% Saturated Water Content), and 40% Relative Humidity. In other places, for example, a Tropical Region where the Sea Level temperature is 40oC with 4% Saturated Water content, numerical values would be different, but would not affect the final conclusions.


  1. Major Gases in the Atmosphere
  2. Heat transfer in the Greenhouse Effect
  3. Anthropogenic Carbon Dioxide
  4. Heat transfer by the Water Cycle
  5. Heat transferred to the Transparent Gases (O2 & N2)
  6. Picture of Heat flow paths in the atmosphere
  7. Conclusions
  8. References

1.Major Gases in the Atmosphere(1)

Figure 1, below, gives quantities of major gases in the atmosphere, for a Temperate Region of the world, where sea level air temperature is 15 degrees Centigrade, and the Saturated Fraction of Water in Air(2) is 1%. Carbon Dioxide and Water Vapour, together, produce the Greenhouse Effect(3). Transparent gases, which occupy about 99 per cent of the whole atmosphere, are so-called because they do not absorb radiant energy. Another Greenhouse Gas, Methane, is present in the atmosphere, but in quantities measured in parts per billion (ppb), so doesn't qualify as a Major Gas.

Figure 1

Carbon Dioxide400 parts per million0.04%
Water Vapour (@40% humidity)4000 parts per million0.4 %
Transparent gases
Nitrogen770,000 parts per million76.6%
Oxygen220,000 parts per million22.0 %

Additional notes on Water Vapour: -

2. Heat Transfer in the Greenhouse Effect

The heat energy transferred in the Greenhouse Effect follows a flow path from, (a) Greenhouse Gases absorb solar and infrared radiation, and store it as sensible heat(4), to (b) Greenhouse Gases relay sensible heat to transparent gases Nitrogen and Oxygen, by contact.

Figure 2 - based on Figure 1 - shows the breakdown of a typical 1 million molecules of the atmosphere in a Temperate Region.

Figure 2

[2.1 + 2.2] is the Total Heat Source of the Greenhouse Effect. [2.3 + 2.4} is the Heat Sink. Transfer of sensible heat from Source to Sink is by contact - 4,400 Source molecules to heat 990,000 Sink molecules. Of the Total Heat Source, Carbon Dioxide molecules are outnumbered, ten to one, by Water Vapour. So, Carbon Dioxide molecules deliver only a minor proportion (one eleventh) of the total Greenhouse Effect.

3. Anthropogenic Carbon Dioxide

Records show that there has been a steady increase in CO2 in the atmosphere since the start of the Industrial Revolution. A causal link between ACO2 and Global Warming is not a scientific fact.

A report in the Daily Telegraph of September 22nd 2014, says that, "Global emissions of carbon dioxide - the biggest contributor to global warming - is on course to reach a record high of 40 billion tonnes in 2014"; certainly a very large quantity. However, the weight of the Earth's atmosphere is 5 quintillion tonnes, so the proportion of ACO2 put into the atmosphere in 2014 was 40 x 109 / 5 x 1015 = 8 parts per million, (0.0008 per cent of the atmosphere per annum). In Figure 2, a sub-set for ACO2 under (2.1) would be 8 molecules. The extra small quantity of heat delivered to the transparent gases, (8/400 = 1/50), would very likely be lost within random variations in the other much larger quantities of heat exchanged in the processes.

(In 2009 the accepted figure for CO2 in the atmosphere was 375 ppm. In this report a figure of 400ppm is quoted. In 8 years the figure has changed by 25 ppm = 3+ ppm per year.)

4. Heat Transfer by the Water Cycle

The great mover of water around the Earth's atmosphere is the Water Cycle(6). It is powered by Solar Radiant Energy which has been absorbed by the surfaces of the Earth. Rainwater falling on these warmed surfaces, evaporates into Water Vapour, which rises in the air due to its buoyancy (relative specific gravity 0.6). The vapour rises to a level in the troposphere where the cold air temperature causes it to revert to droplets of liquid water, at which point Latent Heat of Condensation is discharged, at the higher altitude, directly into the transparent gases Oxygen and Nitrogen. The value of the Latent Heats is 2280 kilojoules of energy per kilogram of water. There are many kilograms of water always being evaporated and condensed to form clouds, so many, many kilojoules of energy, which had originally been solar radiation absorbed at ground and sea level, are continuously entering the atmosphere.

5. Heat Transferred to the Transparent Gases (O2 & N2)

6. Picture of heat flow paths in the atmosphere

Temperate Region of the Earth's atmosphere and 40% Relative Humidity

7. Conclusions

  1. The mass of Anthropogenic Carbon Dioxide in the World's atmosphere is too low to cause "dangerous" Global Warming.
  2. In the Greenhouse Effect, Water Vapour delivers far more heat to the atmosphere than Carbon Dioxide delivers.
  3. Climates are determined by Water in all its three phases, Solid Ice, Liquid Water and Water vapour.
  4. "Decarbonisation" is an extravagant waste of resources.

8. References

(1) Major gases in the atmosphere - The Encyclopaedia of Earth
(2) Saturated Fraction of Water in Air - Wikipedia - The Free Encyclopaedia
(3) Greenhouse Effect - Wikipedia
(4) Sensible heat = mass x specific heat x temperature change
(5) Charts of Relative Humidity in the UK (1971 - 2000)- Wikipedia
(6) The Water Cycle - Wikipedia

John M Dent BSc (Eng.)
February 27th 2017