Michael Gorman
January 2007
I am writing this as a reply to an orthodox statement of the proposition that global warming is a threat to humanity and we must do something about it. I argue that global warming is a threat, but is due to natural causes which we cannot prevent. Let me emphasise that I accept that climate does change.
I have been asked why I challenge the formal reports of a grand committee of scientists sponsored by the United Nations. I have several reasons.
Firstly, I can cite several examples where the scientific establishment has been mistaken. There was the phlogiston theory of combustion, overturned by Priestley's discovery of oxygen and his measuring that the weight of the oxide from combustion was greater than the weight of the original combustible. Another example was in the place where I studied geology, the Sedgwick Museum, Cambridge, England. Mounted on display near the entrance was a Cambridge University examination paper from the 1850s, a year or two before Darwin published his famous book, On the Origin of Species. One question asked, "Explain why the theory of evolution is mistaken".
Secondly, I studied for my degree at a time before British universities had been totally reduced to utilitarian degree factories. We were expected to have an interest in the subject itself, as well as an eye to our future careers. My old university would be disappointed if I did not use the knowledge they imparted to improve public understanding of scientific issues.
My degree is in physics and included the study of chemistry and geology as subsidiary subjects. I am therefore better qualified than most people to comment on issues of climate change. My main reason for so doing is an impression that the scientific grand committees have studied the trends in many sets of data, but have not incorporated them into a convincing geophysical model. Therefore their predictions are open to doubt.
These issues will not be settled by political voting, nor by the social status and authority of individual scientists. What will tell in the end will be the scientific facts and the reasoning behind them. My own analysis follows.
I accept the reality of climate change just as I accept the reality of plate tectonics and of continental drift. But just as these latter two processes operate on a geological timescale, so does climate change. On those time scales, the planet is still emerging from the last ice age which ended some twenty thousand years ago. However, during the last two million years there have been four ice ages. Clearly the first three of them came and went in a way that was not influenced by the industrial burning of coal and oil.
This proves that climate can change for natural reasons. Therefore any claim that human activity is causing climate change must be accompanied by proof that natural causes can be excluded. I have seen no such proof in the current claims.
Geologists can point to other ice ages dating back hundreds of millions of years. They also tell us that for much of its history the Earth was much warmer than at present. Two hundred million years ago, the ancestor of the ostrich and the emu was a big bird that walked its way through the great southern continent of Gondwanaland, which was a green and pleasant land – a total contrast with modern Antarctica. (Then South America and Africa separated off, and the remainder split into Madagascar, India, Australia, New Zealand, and Antarctica; and so the emu and the ostrich were left widely separated.)
This shows that climate can change on a one million year timescale, and on a much longer timescale. There are also shorter time scales. When the Vikings discovered Greenland, they were able to set up farms there. Those farmers perished when the climate later became colder. So there are also climate changes on the scale of centuries.
Nobody knows, or they would have told us, whether the warming observed over the last century, is a thousand year blip, a million year blip, or a return to long term normality. If the cause were understood, then we could surely estimate the timescale; and if the cause is not understood it is difficult to support any proposed remedy. Finally, if it is a return to long term normality, then matters are not out of control as some commentators suggest.
There are two greenhouse gases that affect climate: water vapour and carbon dioxide (CO2). Since the water vapour in the atmosphere is determined by the action of sunlight on the oceans, it is something humanity can do nothing about and it has been ignored in current discussions. I make this point to emphasise the importance of the oceans, since we landlubbers tend to forget that.
It is reported that atmospheric CO2 has increased as a proportion of the atmosphere from 280 parts per million (ppm) to 380 ppm. A concentration of 300 ppm corresponds to a total mass of about a million million tons. The increase in concentration therefore corresponds to an increment of over three hundred thousand million tons.
It is estimated that the industrial world is producing about five thousand million tons of CO2 per year. So if there were no other factors to consider, a century of industry could account for the rise in atmospheric CO2.
But these figures neglect the oceans. For every ton of CO2 in the atmosphere, there are a thousand tons in the oceans, as dissolved CO2 and dissolved carbonate minerals. Oceanic CO2 and atmospheric CO2 are in a dynamic equilibrium, rapidly adjusted for the surface waters, but possibly taking centuries to reach the very deep water. If the atmospheric CO2 has increased by a third of a million million tons, the oceanic CO2 must have increased by between ten and a hundred times that amount. Such an oceanic increase is far too large to be accounted for by industrial burning.
I therefore reject the claim that industrial fuel use accounts for the rise in atmospheric CO2.
The amount of CO2 in the atmosphere is trifling by planetary standards, and is sensitive to natural disturbances. Since the advent of plate tectonics, we have known that there are some very active areas of the ocean floor: the Mid Atlantic Ridge and similar systems in all the other oceans contain many volcanic hot spots. I make a very tentative suggestion, which scientists would call a hypothesis, that there are fluctuations in the number and scale of these hot spots; and that those fluctuations affect the concentration of oceanic dissolved CO2 (and possibly the CO2 in ocean floor sediments). Hence the atmospheric concentration of CO2 will be changed.
An active volcano can spew out a thousand tons of lava per second. Over a year this amounts to thirty thousand million tons of material. Imagine that there are many volcanoes, and that the lava contains an appreciable fraction of CO2. Then the increase in oceanic CO2 is accounted for.
On the basis of these very approximate numbers, I suggest that there should be much more scientific study of the oceans.
Global temperatures are affected by the atmospheric greenhouse gases, water vapour and carbon dioxide. This essay emphasises that both these gases are predominantly affected by the oceans, and not by human activity. Climate change has occurred throughout the geological history of the Earth, on irregular time scales of centuries, millions of years, and hundreds of millions of years.
A non-religious person will readily accept that the Earth was not designed for human life. Depending on the exact specification of the human genus, there have been men on this planet for about four million years, or about one thousandth of the age of this planet. We evolved into existence at a time that was suitable for us, and we may evolve into extinction if things turn against us. Before then, we may witness population growth in some areas, and decline in others, as different areas of the globe become more suitable for us.
If anything, this message is more stark than the orthodox claim that we must control our CO2. The orthodox claim says that we can overcome these changes. This essay suggests the contrary, that change will be forced upon us anyway. Professor Stephen Hawking has suggested that the long term future of the human race depends on our establishing colonies away from this home planet. Unfortunately such ideas are for the near future neither feasible nor affordable in engineering terms.
Copyright © M. J. Gorman, 2007