Before we can discuss this "hot" political topic in meaningful terms, we must first try to define what we mean by "climate". Strictly speaking, there is no such thing: climate is at best only a statistical abstraction from compilations of meteorological data.
Wherever we live on Earth, we all experience weather and we know that weather is subject to constant change. Under the aegis of the World Meteorological Organisation (WMO), Meteorological Observers at "observing stations" around the world regularly and carefully observe and record descriptions of the local weather in a universally standardised form, including parameters which lend themselves to measurement by "scientific" instruments. For our immediate purpose, the most important of these is the temperature of the air a little above ground level.
Observers make their observations at set hours. They record cloudiness, wind direction and speed, visibility, any current precipitation (drizzle, rain, snow, etc.), atmospheric pressure, and air temperature. Observers on ships include sea surface temperature in their observations. Once each day, stations on land note the maximum and minimum temperature recorded and the total amount of precipitation that fell during the previous 24 hours.
Such parameters as can be recorded in figures are analysed to yield daily, weekly, monthly, yearly, etc., means or averages, and compiled into tables "summarising" the weather recorded at the observing station in question during the period. The averages for "clusters" of neighbouring stations are then combined and averaged again to give regional, national, continental, etc. "climatological" tables. The wider the net is cast, the further the data are removed from lived experience "on the ground" at any particular time. Thus "climate" is only an impression formed in the mind of the peruser of a climatological table. Hence the term "global warming" is both more meaningful than "climate change" and more relevant to current political concerns.
We should note that worldwide systematic recording of meteorological data did not begin until after the establishment of the WMO in 1950. Since then, the coverage, accuracy, and sophistication of data capture has increased enormously, not least because of remote observation from satellites. Yet the Intergovernmental Panel on Climate Change (IPCC) takes 1750 as its "base year", and I think I can say without much fear of contradiction that in 1750, very little was known about atmospheric conditions as compared with the vast amount of data accumulated between 1950 and 2009.
The use of computer models based on only 60 years' worth of data to extrapolate future large-scale long-term changes in global atmospheric conditions is of questionable value and is liable to mislead not only "scientists" and statisticians but, and potentially more dangerously, the politicians, journalists, and propagandists who intervene between meteorologists and the public.
All natural phenomena exhibit cyclic periodicity. There are short cycles within longer ones within still longer ones.... Computer models of the atmosphere are therefore of value only to predict short-term variations over a few days. Attempts to extend computations to a timescale similar to that applicable to the life-expectancy of the average politician are rendered invalid by "computational instability" arising from theoretical uncertainty and minor inexactitudes in the original data which increase exponentially with computational time. Hence the dire consequences forecast by people with their own axes to grind are most likely to be nothing more significant than other products of their over-heated imaginations.
The Universe vibrates in various modes, and it would take a foolhardy or unusually disingenuous scientist to pretend that he or she understood the reasons for all of the variations or the manner in which they come about. I feel quite sure that there have been several ups and downs in mean temperature near the Earth's surface in various places during the 26 decades since 1750, and we are told of archeological evidence that the Earth's polar ice caps have grown and shrunk several times in the course of a few million years.
Hence projections based on minor variations in a mere sixty years' worth of data hardly constitute a good basis for predicting even short-term variations and have little or no value for predicting either the onset of major changes or the likely consequences in terms of future weather patterns.
The theory currently put about as an explanation for recent rises in mean surface temperature is that the burning of fossil fuels has increased the atmospheric content of certain gases, notably carbon dioxide, which are present in the atmosphere in very small amounts. Such gases are transparent to the high-frequency radiation from the Sun but absorb some of the lower-frequency radiation from the Earth and reflect it back to Earth, thus slowing the rate at which heat from the Earth's surface is radiated back to space.
The following is taken from the Web site of the UK Health and Safety Executive:
"Carbon capture and storage (CCS)
Carbon dioxide (CO2) is considered to be the main cause of global warming and the level of CO2 in the earth's atmosphere is rising as a result of human activities. Part of the solution could be to capture millions of tonnes of CO2 produced by industrial process and store it deep underground.
Carbon capture & storage (CCS) is the process of capturing the CO2 that is emitted when fossil fuels are burned. It involves capturing the carbon before or after combustion and storing it underground in depleted oil and gas fields, coal seams or deep saline aquifiers. Because it avoids the release of CO2 into the atmosphere, CCS is being developed as a way to help limit climate change.
HSE along with other regulatory bodies and stakeholders are working together to enable a safe working introduction of this process."
Attentive reading of the three paragraphs quoted above makes me fear that people all around the world are being carried away on a cloud of poisonous nonsense emitted by politicians and fanned by journalists.
Take, for instance, the second sentence in the second paragraph above. If carbon were by some strange means to be removed from fossil fuels before combustion, what exactly would be left to burn? Is it not the exothermic chemical reaction of combining hydrocarbons with oxygen that liberates both the heat and the carbon dioxide which is emitted as a by-product of this reaction which we call "combustion"?
By the time the carbon dioxide appears, the heat that warms the atmosphere has already been released. Locking the carbon dioxide away in holes in the ground at enormous expense is tantamount to locking the stable door after the horse has bolted.
A huge stretch of imagination is required to picture the "carbon footprint" so frequently mentioned by politicians to lead the public astray, and I can't decide whether mine consists of soot or of diamonds.
Compared with nitrogen and oxygen, which together account for about 99 per cent of the make-up of the atmosphere, carbon dioxide is currently reported as amounting to only about 0.038 per cent which is very close to the 0.04 per cent which was said to obtain when I was at school sixty years ago.
We should therefore be wary of predicting any serious long-term change in climatic conditions solely as a consequence of a barely detectable variation in a minuscule amount of carbon dioxide and in mere traces of other so-called "greenhouse" gases in the atmosphere. If such gases were really to perform all the wonders attributed to them, we should feel as warm by night as by day.
Weather is an atmospheric phenomenon and the principal driving force is radiation from the Sun. This is modified by conditions at the Earth's surface.
Although the IPCC refers to a "Solar constant", it would be unwise to assume that the rate of incoming electromagnetic radiation from the Sun is constant. There is good evidence of variations in the Sun's output correlated with observed "Sun spot" activity.
The Sun warms the side of the Earth which is exposed to its rays. As the Earth spins on its axis and makes its annual circuit around the Sun, so different parts of the Earth are affected differently at different times. Variations in insolation (incoming radiation from the Sun) are least in the tropics and greatest at the poles.
The effect of insolation is greatest when it strikes the surface of the Earth vertically. Hence the tropics tend to have little variation in temperature throughout the year. The further the location from the equator, the more radiation "glances off" the surface and the less heat is transferred. The annual variation in effective insolation gives rise to the seasons of the year. This effect is, of course, most extreme at the poles, where it is further accentuated by coverings of snow and ice reflecting almost all insolation back to space.
Land heats up and cools down more quickly than water. Hence large arid desert areas near the Equator experience extreme variations in air temperature between night and day, whereas typical daily ranges of air temperature in islands and coastal regions are very much less.
In general, the Earth's atmosphere is transparent to high-frequency radiation, i.e., it allows a high proportion of direct insolation from the very hot Sun to reach the surface of land and sea. The atmosphere is warmed chiefly by re-radiation of heat at much lower frequency from the surface of land and sea and also by the latent heat contained in moisture evaporated from the surfaces of oceans, lakes, etc.
Warm moist air is lighter than cold dry air, and therefore tends to rise from the warming surface, whereas heavier cold dry air tends to descend and take its place. This gives rise to convection, a phenomenon which is easily demonstrated in a school laboratory. The very large convection cells set up in the atmosphere by differences in temperature give rise to variations in the pressure of the atmosphere at the surface of the Earth, and these in turn detemine the direction and speed of the wind at any given point and time. The wind helps to mix the gases in the atmosphere and so tends equalise the local air temperature, i.e. to re-distribute heat from warm areas to cooler ones.
The amount of water vapour a given volume of air can contain depends on its temperature: warm air can hold more water than cold air. Warm moist air cools as it rises and the water vapour it contains condenses to form clouds of water droplets. This process liberates the latent heat acquired during vaporisation of the water and thus slows the rate at which the atmosphere cools with height above the Earth's surface. Whereas dry air cools at the "dry adiabatic lapse rate" of about 5 deg. C per kilometre, warm moist air cools at about half this rate and the effect "tapers off" until all the water vapour in a given "parcel of air" has condensed.
The reader will by now have gathered that reliable "scientific" knowledge on such a vast scale as that comprising Earth and its atmosphere is very far from complete. Uncertainty is further increased by the ocean currents which also re-distribute heat around the Earth and the full effects of which are still problematic although I have recently seen it suggested that relatively warm ocean currents may be the chief agency involved in melting polar ice in Antarctica.
Insofar as human beings have any influence on the circulation of ocean or atmosphere and the heat therein, I have no hesitation in asserting that any such influence is rather small and of very short duration by comparison with that of the Sun. I can also point to a mechanism which is far more direct and almost certainly more significant than liberation of carbon dioxide.
In 2009, the human population of Planet Earth is far greater than at any time in recorded history and every single one of about eight thousand million people wants to feel neither too cold nor too hot. Ever since man learned how to control fire, a fireplace of some sort has been a feature of nearly every home in latitudes outside the Tropics.
Human aversion to muscular drudgery and desire for speedy satisfaction of every whim extended the application of fire to the performance of all kinds of physical work. Steam and internal combustion engines relieved man from back-breaking toil and greatly accelerated all forms of transport. Mechanisation of all manner of crafts consigned homespun clothing, handmade furniture, and the concoction of herbal remedies to the pages of history and replaced them with factories, fashions, and huge impersonal chemical and pharmceutical industries. These changes constituted the Industrial Revolution and the energy used in nearly all of them was extracted from fossil fuels of some kind.
In more recent times, man's mastery of electricity has led to further significant changes. Roads, streets, and even motorways are now nearly as bright by night as by day. Refrigerators, air-conditioning units, and all manner of electrical gadgets for heating, cooling, cooking, washing, gardening, lighting, and entertainment have revolutionised the domestic environment in "developed" countries. Nearly all the electricity used has been generated by burning fossil fuels.
All these changes have fundamentally altered the nature of human employment. Nearly everyone is now a "white-collar worker" engaged in some form of communication and information processing in an endeavour to enable directors and managers to control complex operations all over the globe. Air transport has made the entire world a playground for those who have enough money to pay the fares. Nearly every house in the road in which I live has to find parking space for two or three private motor cars. Aircraft and motor vehicles burn fossil fuels.
None of these "advances" would have been possible without copious supplies of cheap energy-rich hydrocarbons all of which are ultimately nothing but capital saved over countless millions of years through storage of solar energy in the bodies of formerly living organisms.
The burning of hydrocarbons certainly produces carbon dioxide: but far more importantly, it involves liberation of the heat stored in the wood, peat, coal, oil, and gas. Return to the atmosphere in the space of two or three centuries of energy accumulated in the Earth over countless millennia is bound to have some effect in warming the atmosphere. Nevertheless the effect, though large by comparison with that of "greenhouse gases", is very small by comparison with Solar input and it will be of extremely short duration by comparison with the Sun's remaining expectation of life. Hence any discomfort that may arise from "man-made" global warming contains the seeds of its own alleviation. The real discomfort will arise from inevitable drastic reduction in supplies of cheap hydrocarbons and deprivation of the conveniences which hydrocarbons make possible.
Here in the UK, we are becoming anxiously aware that domestic supplies of "North Sea Oil" and natural gas are "running out". It is a major cause for concern that we shall in future have to rely on foreign imports of the commodity on which we depend for nearly all the comforts and conveniences to which we have allowed ourselves to become accustomed.
Exploitation of readily-available oil and gas not only keeps our homes at comfortable temperatures and powers all our "heavy" industries. Oil is also the raw material from which chemical and pharmaceutical industries produce fertilisers, medicines, plastics, and much else that goes into the fabrication not only of our homes but also of many of our utensils and utilities which nowadays include televisions, computers, and all manner of communications devices.
Hydrocarbons are daily getting more difficult to reach and extract, so their cost is already rising. Demand increases exponentially with ever-rising populations and accelerating industrialisation of "developing countries". The informed consensus among those who give serious thought to these matters is that the point of "peak oil" was reached in about 2006, and that unless we can drastically reduce our rate of consumption, we must henceforth expect a rapid decline in worldwide supply and a corresponding increase in cost.
As I write, politicians are meeting in Copenhagen with high hopes of reaching an internationally binding commitment to "restrict emissions" by some notional percentage by 2050. Such an outcome might bring some comfort to world populations which have over the past decade been feverishly indoctrinated with psychological fear of an evil carbon dioxide which has been forced into playing the role of the Devil in recent political theology. This might help politicians to enrich themselves for a few more years with the taxation they will attempt to justify as being required to develop sources of "green" carbon-free energy. It will do nothing to alter material facts which will soon become too obvious to conceal with rhetorical flim-flam.
The most significant fact that politicians deliberately ignore because it is too unpalatable is that unless they can soon find a politically acceptable way of rapidly reducing the human population of Planet Earth, the nasty carbon-emitting oil and gas will by 2050 will be so expensive that only a small minority will be able to afford it. I am not aware of any realistic prospect that satisfactory alternatives will by then be economically available on a scale anything like that required to sustain the human population of the world at present levels. So please let your imagination range for a while over the consequences for yourself and your descendants of a world without affordable hydrocarbons.
Please also reflect that hydrocarbons (compounds of carbon and hydrogen) are chemical first cousins of the carbohydrates (compounds of carbon and water or, in other words, of carbon, hydrogen, and oxygen) which constitute a most essential proportion of the food we eat and whose conversion into water, carbon dioxide, and heat keeps our bodies at a nearly constant temperature. Every breath we exhale contains a higher proportion of carbon dioxide than the air we inhaled. Do we really want to restrict our breathing just to please a few politicians whose principal concern seems to be nothing more important than the extension of their own careers?
Before you take anything I say as "Gospel Truth", I advise you to seek the kind of supportive evidence that politicians would rather keep from you. You might start by resorting to the Internet and searching on "wolfatthedoor", "peak oil", and "oil drum".
The explosion in the human population of the planet is drawing attention to probable "peaks" in supplies of other essential commodities such as food and clean fresh water. Roads and buildings encroach on arable land. The headwaters of rivers and streams are diverted to local purposes with the effect that little water is left for the people on the plains. Fishing grounds are depleted at a rate beyond compensation by natural fertility. It would not be surprising if other species viewed the human explosion as a deadly cancer.
This cannot continue. Politicians cannot do anything but talk and try to tax. Cold, famine, wars, and diseases will sooner or later dispel all comfortable political illusions. The lowest forms of life will gain notable victories in the population competition, and great conurbations of sophisticated humanity will give way to widely scattered remnants.
The end of the "world as we know it" is inevitable, but the prospect should not daunt us. Today's world is certainly not the happiest of places, and any improvement implies change.
I hope that readers of these pages will be among an optimistic minority determined and spiritually prepared to survive and thrive in "a world beyond oilwells". It will also be a world beyond over-crowding, and there will be no shortage of food, water, or warmth for those who retain the knowledge of how to secure them.
Of course, this will mean returning to a simpler way of life similar to that which sustained our remote ancestors and which still prevailed in the tiny West Highland community in which I was nurtured. There was little leisure, but people talked and laughed and sang as they worked.
The most important thing to ensure is that whatever regression may be necessary in our material progress, whatever spiritual progress we may have made can be sustained and even accelerated in the absence of frivolous distractions.
Let us prepare as best we can for our next incarnation.