Reposted: Why Man-made CO2 does not cause warming


Comment from Diogenes Despairs

In this post

An essay comment from Diogenes Despairs

The fact is, there has been global warming, but the contribution of human-generated carbon dioxide is necessarily so small as to be all but undetectable. Here’s why:

Carbon dioxide, considered the main vector for human-caused global warming, is some 0.04% of the atmosphere by volume, or some 400 parts per million (ppm) [1]. Water vapor varies from 0% to 4% by volume [2], and so should easily average above 1% [3] near the Earth’s surface, where the greenhouse effect would be most important, and is about three times more effective [4] a greenhouse gas than carbon dioxide.  So, water vapor is some 25 times more prevalent and three times more effective; that makes it some 75 times more important to the greenhouse effect than carbon dioxide [5]. The TOTAL contribution of carbon dioxide to the greenhouse effect is therefore 0.013 or less.

Since the start of the industrial revolution, carbon dioxide is estimated to have risen from 280 ppm to the current approximately 400 ppm. Even if the entire increase were the result of human emissions – which is by no means certain, given uncertainty about how much CO2 is produced by natural sources such as decomposition of biomass and carbonate rock, volcanism and the little-understood ocean-atmosphere exchange – the total human contribution to atmospheric carbon dioxide would be about 0.3 of the total. Therefore human carbon dioxide adds at most only 0.0039 of the greenhouse effect, and may well be less.

Total warming of the Earth by the greenhouse effect is widely accepted as about 33°C raising average temperature to 15°C. So the contribution of anthropogenic carbon dioxide is at most 0.13°C, and perhaps considerably less. Global warming since the beginning of the industrial revolution is thought by many to be perhaps 0.8 to 1.0°C.

But that’s only the beginning. We’ve had global warming for more than 10,000 years, since the end of the last Ice Age, and there is evidence temperatures were actually somewhat warmer 9,000 years ago and again 4,500 to 8,000 years ago than they are today [6]. Whatever caused that, it was not human activity.

It was not all those power plants and factories and SUVs being operated by Stone Age cavemen while chipping arrowheads out of bits of flint. Whatever the cause was, it melted the glaciers that in North America once extended south to Long Island and parts of New York City [7] into virtually complete disappearance (except for a few mountain remnants). That’s one big greenhouse effect!

If we are still having global warming – and I suppose we could presume we are, given this more than 10,000 year history – it seems highly likely that it is still the overwhelmingly primary cause of continued warming, rather than our piddling 0.0039 contribution to the greenhouse effect.

Yet even that trend-continuation today needs to be proved. Evidence is that the Medieval Warm Period centred on the 1200s was somewhat warmer than we are now [8], and the climate was clearly colder in the Little Ice Age in the 1600s than it is now [9]. (Whether the earlier Roman Warm Period around the time of Christ was as warm or was warmer than present is less clear.) So we are within the geologically recent range of normal up-and-down fluctuations without human greenhouse contributions that could be significant, or even measurable.

Principal scientists arguing for human-caused global warming have been demonstrably disingenuous [10], and now you can see why. They have proved they should not be trusted.

The idea that we should be spending trillions of dollars and hamstringing the economy of the entire world to reduce carbon dioxide emissions is beyond ludicrous in light of the facts above; it is insane.

Furthermore, it sucks attention and resources from seeking the other sources of warming and from coping with climate change and its effects in realistic ways. The true motivation underlying the global warming movement is almost certainly ideological and political in nature, and I predict that Anthropogenic Global Warming, as currently presented, will go down as the greatest fraud of all time. It makes Ponzi and Madoff look like pikers by comparison.



What initially troubled me, years ago, was the aberrant behaviour of the climate research unit at East Anglia University, which had been the main data source for AGW arguments. They initially refused (!) to reveal their algorithms and data on the grounds that they were proprietary(!!). They responded to critics with ad hominem attacks and efforts to block their publication in scientific journals. Now, as I am sure you know, this is not how one does honest science, in which you PUBLISH your data and methodology and invite critical comment to ferret out error or oversights. It took the now-famous Wikileaks “Climategate” to pry loose the data and expose their machinations. Yet despite the devastating blow these revelations should have to their credibility, the AGW “cause” has taken on a life of its own.

Fundamentally, the argument seems to rest on a logical fallacy, post hoc ergo propter hoc – after this, therefore because of this. We see a rise in temperature and a rise in (principally) carbon dioxide, and therefore conclude one must have caused the other. It does not necessarily follow at all. There can be other causes entirely behind both phenomena, and as you see above, almost certainly there are. Beyond that, I have encountered numerous assertions of fact that cannot add up given the physical properties of water vapor and carbon dioxide that go unchallenged. One-sided arguments proliferate and people arguing the other side are frequently denounced as being employed by business interests rather than rebutted on the merits.

In sum, I have not come lightly to the conclusion that the AGW argument as it applies to carbon dioxide is largely untrue and certainly does not account for more than a very small, nearly negligible part of the phenomena we are seeing. The implications of widespread assertions of and belief in such an untruth are staggering, and potentially enormously destructive. It is unwise indeed to let oneself be stampeded in this matter, and stampede is clearly what many have been and are trying to induce.

I can understand politicians behaving this way; a carbon tax or carbon trading regime would allow enormous revenues to fall into their hands. I can understand “Progressive” ideologues; it logically leads to enormous expansion of government power over industry, the economy, and the daily life of individuals, which they regard as a good thing. I understand the environmentalists; they want to shrink the size and impact on the environment of modern civilization. But responsible citizens need to put aside such considerations when drawing conclusions.

Please feel free to copy this essay and post it wherever you think it may do some good. The more people who understand this the better.




[1] Mauna Loa Observatory…

[2] Fundamentals of Physical Geography, 2nd Edition

by Micheal Pidwirney Concentration varies slightly with the growing season in the northern hemisphere. HYPERLINK http://www.physicalgeograph…

[3] The Earth’s tropics, the so-called “Torrid Zone,” where temperatures and therefore the capacity of the atmosphere to hold water vapor are at their highest, and where the 4% maximum is found, comprise a far greater portion of the Earth’s surface – 40% – than do the areas where water vapor content is at its lowest, the polar areas (8%), and the world’s deserts (10%). Moreover, the troposphere, which contains 99% of the world’s water vapor, is far deeper at the equator (10-12 miles) than near the poles (4 to 6 miles), enabling substantially more water vapor retention in the tropics even if other factors were equal rather than favoring more water retention rather than less. I have chosen an arbitrarily low working figure of 1% to give the AGW argument the benefit of any doubt. The higher the actual figure is above that, the lower must be the actual contribution of carbon dioxide, and therefore of anthropogenic carbon dioxide. If the true figure is 2%, the contribution of human-generated carbon dioxide is half that shown.

[4 NIST Chemistry Webbook, Please compare the IR absorption spectra of water and carbon dioxide. ] HYPERLINK “”

[5] Three quarters of the atmosphere and virtually all water vapor are in the troposphere. Including all the atmosphere would change the ratios to about 20 times more prevalent and 60 times more effective. However, the greenhouse effect of high-altitude carbon dioxide on lower-altitude weather and the earth’s surface seems likely to be extremely small if not nil, given that heat rises and high-altitude gases would also intercept relevant frequencies of solar radiation before they reach the earth.

[6] Encyclopedia Britannica – Holocene Environment and Biota, et al.… for early holocene. See also History of Earth’s Climate, Ch. 7, Brett Hansen… The citation here is of the English translation, which contains minor grammatical errors that do not materially affect content.

[7]The Narrows Flood – Post-Woodfordian Meltwater Breach of the Narrows Channel, NYC Charles Merguerian… p. 2, et al.

[8] Britannica, same section… for historical period: Roman and Medieval Warm Periods also History of Earth’s Climate, Ch. 7, Brett Hansen…

[9] University of Arizona…

[10] Wikileaks: Climatic Research Unit emails, data, models, 1996-2009 HYPERLINK “…”….


See also

HYPERLINK “…”… and

HYPERLINK “…”… and, more diplomatically: HYPERLINK “…”…. Et al.