A New Scientific Law and The Greenhouse Effect
This elementary article could have, and should have, been written and published long ago. The condensation of water vapor to form dew or frost on solid natural and artificial surfaces is a commonly observed natural phenomenon. It is well understood that the latent heat released as water vapor condenses slows the radiational cooling of these surfaces during the diurnal temperature cycle.
There can be little doubt that the ability of atmospheric water vapor to condense (releasing its significant latent heat of condensation to its environment) limits the minimum possible temperature of the common diurnal temperature oscillation. The ability of this same atmospheric water vapor (and certain other atmospheric gases) to absorb portions of the radiation emitted by the earth’s surface has nothing to do with this minimum temperature limitation.
In 1896 Svante Arrhenius (1) reported, in English, his well known radiation balance calculation. He noted that Joseph Fourier (2) in 1827 put forth the idea that “the atmosphere acts like the glass of a hothouse, because it lets through the light rays of the sun but retains the dark rays from the ground.” But relative to this present article, he noted that John Tyndall (3) in 1865 thought “it was chiefly the diurnal and annual variations of the temperature that were lessened by this circumstance.” It seems all three of these promoters of the well known greenhouse effect hypothesis (current theory) had to have seen dew or frost to form on surfaces as the atmosphere, in contact with these surfaces, cooled during the night until the next morning when the sun again began to warm the earth’s surfaces.
The new scientific law is: The surface temperature of an object, at thermal equilibrium with the atmosphere in contact with it, can be no lower than the dewpoint (the temperature at which the atmosphere is saturated with water vapor) of the atmosphere in contact with it. This law is related to another known scientific law of meteorology which I have never seen being referred to as a scientific law. Instead, one only reads: “The atmosphere has never been observed to be supersaturated with water vapor.” Because this statement seems not to have been acknowledged to be a scientific law, it seems there is a need to review what a scientific law is and its critical role in modern science.
A scientific law is merely a summary of similar observations for which there has never been observed an exception. It is not a hypothesis, not a theory, not an explanation; it merely predicts what will be observed in specific circumstances. It cannot be proven by reason and it can only be disproved by an observation that is an exception to the summary. Scientific laws (observation) played a critical role in the founding of modern science little more than 400 years ago. Up to this time philosophers had used reason and debate to determine their truths. But Galileo Galilei changed this as he began to use observation (sometimes experimentation) to refute certain ‘truths’ that had been established by the Greek philosophers nearly 2000 years earlier. While the natural philosophers who followed Galileo primarily observed, they also reasoned about that which they observed. However, these natural philosophers adopted sets of rules to limit their reasoning.
Newton began his Third Book of The Principia with his set of rules. The first two, with his commentary, were (as translated by Andrew Motte): Rule 1 “We are to admit no more causes of natural things than such as are both true and sufficient to explain their appearances. To this purpose the philosophers say that Nature does nothing in vain, and more is in vain when less will serve; for Nature is pleased with simplicity, and affects not the pomp of superfluous causes.
Rule 2: “Therefore to the same natural effects we must, as far as possible, assign the same causes. As to respiration in a man and in a beast; the descent of stones in Europe and in America; the light of our culinary fire and of the sun; the reflection of light in the earth, and in the planets.”
When one reviews Svante Arrhenius’s radiation balance calculation, it is clear that he violated Newton’s second rule of reasoning. For he used the albedo of clouds to reduce the amount of the sun’s radiation which reached the earth’s surface but did not consider the same clouds could limit the earth’s radiation transmission to space. Again, he had to have been aware of the difference between clear and cloudy winter nights in Sweden.
In conclusion, far too long it has been accepted that the abilities of certain atmospheric molecules to absorb a portion of the radiation emitted by the earth’s surface limits the earth’s surface temperatures from falling far lower than it is observed they do; whereas, it is clearly the vapor pressure of water vapor in the surface atmosphere which limits the minimum temperature of the diurnal temperature cycle.
References:
- Svante Arrhenius, On the Influence of Carbonic Acid in the Air upon the Temperature of the Ground, Philosophical Magazine and Journal of Science (Series 5, Volume 41, April 1896, pages 273-276.
- Joseph Fourier, Mem. De l’ Ac. R. d. Sci, de l’tInst. De France, t. vii, 1827.
- John Tyndall, ‘Heat a Mode of Motion,’ 2nd ed. p. 405 (Load., 1865).
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