The anthropogenic global warming hypothesis and the principle of causality


An argument continues to rage in the scientific community over the scientific validity of global climate change and, in particular, global warming. Essentially, the argument concerns the validity of the anthropogenic global warming hypothesis (AGWH), which is the fundamental assumption of global warming (change) science and assumes that the increase in global average temperature is directly caused by human-generated carbon dioxide (CO2) produced primarily by the combustion of fossil fuels.

This assumption also serves as the key assumption of various global warming models, especially those used by the Intergovernmental Panel on Climate Change (IPCC) to predict future global temperatures.

However, this hypothesis predicts the result that the global average temperature increases with the concentration of CO2 in the atmosphere, so it’s no surprise that the models predict exactly that. As anyone familiar with the fundamentals of modeling complex physico-chemical systems knows, such an assumption is illegitimate because of the bias it imposes on the result.

This alone is reason enough to reject the results of the models and it is a good enough reason to develop alternative models that are not encumbered by this illegitimate assumption. However, as devastating as that may be, a much more serious issue exists as to whether AGWH is even correct.

A review of the relevant literature did not uncover any fundamental and scientifically valid support for AGWH, and it appears to have been adopted simply because it was seen by some as describing the “obvious” impact of AGWH. industrialization on the perceived increase in temperature and for a desire of some to return civilization to a pre-industrialization state. However, this perception does not meet the rigorous standards of scientific evidence.

The AGWH seems to have had its genesis in the IPCC mandate in 1988 which seems to have taken as fact that humans are responsible for at least a significant part of current global warming. Therefore, the AGWH became the fundamental assumption of climate science as we know it today.

The fact that the temperature excursion seems to precede that of the CO concentration2 in the atmosphere has been noted by others, but, to the best of the author’s knowledge, has not previously been interpreted directly in terms of the principle of causation, as presented here, which provides the rigorous scientific basis for establish scientific validity or lack thereof.

The principle of causality (CP) comes from Aristotle’s treatise titled “Physiks”, which was published in 450 BC. The CP can be expressed as follows: “Every effect has a cause, and the cause must precede the effect”. Moreover, “for a complex system comprising a series of processes, if a step is non-causal, then the whole process is as well”.

CP can be illustrated with a simple example. A firearm is designed to fire (the “effect”) only when the trigger is pulled (the “cause”). When this happens, the process of firing the weapon is said to be “causal” and consistent with science (via the firing mechanism).

On the other hand, if the weapon fired (the “effect”) before the trigger was pulled (the “cause”), the process is “non-causal” and not allowed by the trigger mechanism. shot (i.e. “science”) and it won’t happen as long as you wish to wait.

AGWH’s compliance with CP will be reviewed in terms of reported CO2 and temperature data from ice core data available in published literature.

The most comprehensive ice core archive is from Lake Vostok in Antarctica. In-depth examination of the temperature anomaly and atmospheric CO2 records show that the drop in temperature precedes the drop in CO2.

As for temperature rises, it’s harder to say because when you look at a small chart of the entire record of more than 400,000 years, it shows that CO2 and the temperature rose at about the same time. However, plots at expanded scales spanning 50,000 years, for example, clearly show that the increase in temperature precedes the increase in atmospheric CO2.

Because it is not possible to distinguish between natural CO2 and co2 resulting from the burning of fossil fuels, the absence of causation as expressed by the AGWH must hold for both.

Since, according to the IPCC/AGWH, the cause of global warming is the emission of man-made CO2 in the atmosphere, the rise or fall of CO2 should precede the rise or fall in temperature, but this is not what is observed.

Accordingly, the relationship proposed by the AGWH between CO2 and temperature change is not causal and not scientifically valid.

It is important to note that, however many such contrary observations can be made in support of the AGWH (i.e., the change in CO2 precedes the change in temperature), a single observation of the change in temperature preceding the change in CO2 is necessary to disprove the AGWH and thus the foundation of current climate science. In other words, the AGWH has been “tampered with”.

There are many sources of CO2 other than humans burning fossil fuels, such as volcanic eruptions, forest fires, animal (including human) respiration, the decay of plant and animal matter, and the world’s oceans which are the great repository of all CO2 whatever its source. Thus, if the change in temperature is responsible for the change in atmospheric CO2 as indicated by the ice core data, then a more logical source/sink of CO2 is the outgassing/absorption of the oceans (as has been noted by many others) in response to changes in the irradiance and orbital motion of the sun, as discussed below.

This process has at least the legitimacy of the cause and effect relationship. It is therefore difficult to find where a direct human element has a negative impact on the whole process.

In fact, higher CO2 levels promote plant growth, as evidenced by the sharp increase in crop yields and the “greening” of planet Earth as the concentration of CO2 in the atmosphere has increased since the beginning of the industrial revolution, as noted by some experts. It can be argued that the reason the Earth can support a population of over 7 billion is due to increased crop yields resulting from higher levels of atmospheric carbon dioxide.

Moreover, by depriving developing countries of cheap and abundant fossil fuels, we would essentially relegate these people to a permanent state of poverty, an outcome that I find morally wrong, particularly because those same fuels lifted my ancestors out of the poverty, an outcome that I continue to appreciate today.

My analysis argues that climate change is not the result of increased CO2, of human origin or not, since this relation is not causal. This then begs the question, “What is the likely cause of the observed increase in global temperatures?”

Although a complete answer to this question is beyond the scope of this article, it is worth noting the strong correlation between temperature and solar irradiance that has been demonstrated. This correlation is much higher than that between temperature and CO2suggesting that global warming is a natural phenomenon linked to variations in our heat source, the sun.

However, it is prudent to be wary of correlations because correlations do not prove causation.

As many authors have noted, the global mean surface temperature (GMST) has shown a slight downward trend since 2001. None of the climate models employed by the IPCC predicted this cooling, which is now called the ” pause “.

It is not surprising to learn that this period corresponds to the maximum of total solar irradiance (TSI), in which the TSI does not change significantly over time or decreases slightly towards the minimum of the next solar cycle.

We should have experienced another solar maximum in 2018-2019 and we should now be on track for the next solar minimum around 2030.

TSI is known to be directly proportional to solar activity as expressed by Greenwich Sunspot Activity (GSSA), a finding that was first discovered through a NASA experiment. The GSSA represents the general level of solar activity.

However, the evidence casts doubt that TSI is the sole driver of temperature change, so the caution previously expressed about correlations is well warranted.

As many others have noted, global warming is undoubtedly a far more complex phenomenon than can be described by human-caused changes in CO.2 in the air. Admittedly, the absence of causality between the change in the concentration of CO2 in the atmosphere and the change in temperature, as discovered here, demonstrates that CO2 level, whether man-made or natural, is not materially involved in the temperature change.

The opinions expressed in this article are the opinions of the author and do not necessarily reflect the opinions of The Epoch Times.


Digby D. Macdonald is a New Zealand native, naturalized American citizen, and Professor-in-Residence (semi-retired) in the Departments of Nuclear Engineering and Materials Science and Engineering at the University of California, Berkeley. He holds a B.Sc. and M.Sc. degrees from the University of Auckland and a Ph.D. from the University of Calgary (1969), all in chemistry. Professor Macdonald has published over 1100 articles in peer-reviewed journals and conference proceedings and has published four books. He is a Fellow of the Royal Society of Canada, the Royal Society of New Zealand (the “National Academies” of these countries and a Fellow of the EU Academy of Sciences. He boasts an H-index of 79 and his articles have been cited more than 27,846 times.

Teresa H. Sadler