The past few decades have seen increasing concerns about the use or the misuse of the environment. This even led to the United Nation Framework Convention on Climate Change (UNFCCC) to monitor the effects of human actions on the environment particularly climate. This could be because almost everyone has witnessed unusual weather patterns that appear to affect their daily lives negatively. In this article, John Moore, who has worked in ecology for most of his professional life, raises interesting issues for reflection on ecology.

There is a legend about Canute, King of England, Denmark, Norway and part of Sweden around 1050 A.D.  His flattering courtiers insisted that he was the all-powerful king and that therefore everything in the world would obey him.  Failing to convince them of the foolishness of   their   flattery, Canute ordered them to bring his throne down to the sea-shore at Bosham in England.  He then ordered the tide not to come in.  It did of course come in and while the waves were lapping about their feet, the King refused to allow his courtiers to move away until they had acknowledged the truth of his proclamation: "Let all men know how empty and worthless is the power of kings; For there is none worthy of the name but God, whom heaven, earth and sea obey".

Now, almost 1,000 years later, perhaps we need a Canute figure to remind us that much of the furore about Climate Change and Global Warming that is almost swamping the media at present, may be based on evidence as flimsy as the assertions of those flattering courtiers of long ago.

Let us look at the scientific evidence. The following facts are based on reliable measurements made over the past few years:

The Facts

1. The concentration of carbon dioxide (CO2) in the lower atmosphere has been steadily increasing in the past centuries.  It is now about 25% higher than it was in 1900. 

2. Since 1980, the annual mean near surface temperature of the Earth has been increasing rapidly; the total rise since then is somewhat less than 0.6ºC.

3. There have been increased losses of ice from the Arctic and Antarctic ice sheets as well as from mountain glaciers.

4. Average sea level has increased by about 17 cm in the 20th century alone.

5. There has been a large number of flood disasters in recent years, the most striking and widely reported one being in New Orleans after hurricane Katrina moved inland.

 

The Hypothesis

This complex of facts is usually referred to as “Climate Change”, or more popularly “Global Warming”, and they are combined into a seemingly plausible hypothesis which runs as follows: Carbon dioxide and other gasses arising from industrial burning of fossil fuels are “greenhouse gasses”.  This means that they allow incoming radiation from the sun to pass through readily but block some of the lower wavelength energy reflected from warmed surfaces.  This so-called “greenhouse effect” leads to global warming which brings about climate change and an increase in weather-related natural disasters. 

The practical conclusion is that governments, as well as individuals, must reduce the emission of CO2 coming from the burning of fossil fuels such as petroleum products and coal. A second step is then to construct computer-based models of this hypothesis in order to predict future climatic changes, especially further warming. This is the scenario that is presumed by most of the political pressure groups who demand that governments enforce reductions in the emission of carbon dioxide in their countries.

 

The Flaw

The hypothesis outlined above has one fatal flaw:  it is presumed that the correlation between the increasing CO2 concentration in the atmosphere and the increase in near surface temperature indicates a causal connection between the two:  the increase in carbon dioxide causes an increase in temperature via the greenhouse effect.

There is one big difficulty about this supposition.  It could be the other way round – temperature increase causing an increase in CO2, or even some third as yet unknown factor influencing both.  How do we decide which is the true situation?

 

A Look at the Past

A look at the past may help us.  For the past two million years the earth has been going through a period of dramatic climatic changes.  There occurred a series of Ice Ages when glaciers covered large areas of northern Europe, Canada and U.S.A.  The last four of these glacial epochs have been well studied in these countries. 

In between these glacial periods the climate warmed up to present levels and the glaciers melted and receded.  Such periods are known as Interglacials.  Geologists refer to our present period as the Post-Glacial, implying that we are finished with Ice Ages. There is no firm basis for such an assumption.  We are, presumably, in the early stages of yet another Interglacial; if the pattern of the past million years persists, we should expect our northern, developed countries to be covered with ice sheets again somewhere about the year 80,000 A.D.

Ice cores two kilometres deep have been taken at the Antarctic Research Station at Vostok.  It is estimated that the ice at the bottom of the core formed about 420,000 years ago.  The concentrations of the gasses in air bubbles trapped in the ice have been measured at regular intervals from top to bottom.  It is possible to calculate the temperature at the time the air bubble formed from the concentration of the isotopes of oxygen or hydrogen.  These measurements show that there is a close correlation between CO2 concentration and temperature over the period of the past four Major Ice Ages and their intervening interglacials.  The curves for CO2 concentration and for temperature are very similar.  Obviously there can be no question of the increase of CO2 during those warmer interglacial periods having been due to human industrial processes. 

Therefore the increases in CO2 must have been due to “natural processes” rather than due to the activities of our Stone Age ancestors.  Similar results have been obtained from other ice cores, especially the one from EPICA Dome-C which is estimated to bring us back 720,000 years and covers 8 Ice Ages with their intervening interglacials.

Some more Facts

1. The estimated maximum near surface temperature during the last interglacial was about 3.2° C above the 1950’s value, whereas the recent increase that is causing such a political furore is 0.6°C. above that figure.

2. The most important greenhouse gas is not CO2 but water, either in the form of vapour or as clouds.  Overall it is estimated to account for 90% of the greenhouse effect in the troposphere.  The other 10% is mainly due to CO2.

Since water is the major greenhouse gas, it is essential that the computer models simulating climate change are accurate in predicting the behaviour of water in the atmosphere, either in the form of atmospheric humidity or in the form of clouds.  However the recently issued fourth Intergovernmental Panel on Climate Change (IPCC) report, in assessing the accuracy of current climate computer models, admits repeatedly that “the seasonal mean amounts of clouds and upper tropospheric water vapour are not well simulated in current climate models” (p. 484, etc.).  This should make us extremely skeptical when we hear about predictions of the large increases in temperature to be brought about by increases in carbon dioxide.

In light of all these facts it seems to me that many of those campaigning for stopping climate change, or global warming, are like King Canute’s courtiers.  These wanted the King to shout louder to the ocean: “Thus far thou goest and no further” so that their elegant footwear would not be spoiled by the advancing tide.  Canute’s famous reply may be a bit shaky from the theological point of view, but its clear message is incontrovertible: we are powerless to control the massive cosmic forces which are being driven by factors over which we have absolutely no control. 

Such factors as have so far been identified are “wobbling” of the earth’s axis of rotation, variation in    high-energy   cosmic radiation coming to us from space and small variations in the energy coming to us from the sun. 

The scientific name for the latter is “The Solar Constant”, but it is not a constant at all.  It does vary, admittedly not very much, but its fluctuations could influence our climate.  For example, the well documented “little Ice Age” in Europe (17th century until about 1860) coincided with a period of low sunspot activity known as the Maunder Minimum between 1650 and 1710, when the incoming energy was definitely diminished.
Any scientist who fails to support the present “politically correct” view about climate change is usually suspected of accepting bribes (more politely called “research grants”) from the giant    companies    involved    in selling traditional power sources, or machines that use them.  I do not receive any such monies nor do I hold a brief for any such commercial interests.  However I am concerned about the large sums (about US$5 billion per annum in the USA) that are being spent on a project which seems to me to be based on a scientifically flawed argument.

I might also be asked how I, who have worked in ecology for most of my professional life, can now be opposed to people being made aware that they need to reduce their “carbon footprint.”  I am not opposed to people cutting down on their wasteful and self-indulgent use of traditional power sources but I am opposed to the way the “carbon crew” have usurped the very fruitful image of the “ecological footprint” and reduced it to mere concern about the increase in the carbon dioxide concentration in the atmosphere, an increase which results in greater crop yields. 

The image of the ecological footprint, properly explained and estimated, provides a far better index to show people in the “developed” countries that they are living in an unacceptably extravagant way. The “ecological footprint” is the amount of biologically productive land and sea needed to provide the renewable resources we use.  The “ration” of such productive land and sea available to each inhabitant of the world today is 1.7 Ha. 

The average ecological footprint of an inhabitant of the USA was calculated in 2003 to be 3.5 Ha (omitting the CO2 component).  This means that we would need two Earth planets to support us if we were all to adopt the way of life of an average citizen of the USA.

 John J. Moore, S.J.
Arrupe College
Harare