Fossil fuel consumption is accompanied by emission of carbon dioxide and corrosive gases such as the oxides of sulphur and of nitrogen. Nuclear power is very attractive in some of its short term aspects (being innocent of such emissions) but the long-term hazards are not known with sufficient precision to warrant present gambles with future well-being. In any case, both fossil and usable nuclear resources are finite. The 'renewable' - better termed 'perpetual' - resources of wind and wave are less than fully dependable at any given time and place and are usually inefficient in respect of energy output per unit area of the installations and, in many instances, they are liable to be noisy in operation and ugly to the eye.
What to do?
It is perhaps as well to reflect upon the fact that the primary source of energy available to us terrestrials is solar radiation. It is well known to everyone that a proportion of the energy emitted by the sun is used by green plants to synthesise carbohydrates from two of the gases of the atmosphere - carbon dioxide and water vapour. Indeed, fossil fuels themselves are the end products of the transformation of buried vegetation from long past ages. When carbohydrates are burned (or digested) the reverse occurs. Important carbohydrates include familiar substances such as cellulose, starch, glucose and cane-sugar.
Schematically (the actual reactions are more complex) these processes are:
In the early 1940's, my fellow students and I were assigned the task of writing papers on Organic Chemistry and Economic Self-Sufficiency. This subject (economic self-sufficiency) was of some interest at the time (not like nowadays, when international trade is thought to be an end in itself, when I can buy cheap pyjamas of Korean manufacture while my neighbour not many yards away can make such things very easily and might be glad of the work at not all that much more than a Korean rate of pay). This interest arose partly because the Germans had done a lot of work on making themselves less and less dependent upon imported materials that could, at a pinch, be made from coal and their other indigenous resources. Another fact was the rapid development of the petrochemical industry and its ability to make a huge range of useful materials from petroleum - particularly from ethylene - a gas that was produced in large amounts during the process of making motor fuels from crude oil. Much of the ethylene so produced was, and is, combined with water to make alcohol
A line that many of us considered was the possibility of some countries growing huge amounts of sugar-cane (or sugar beet) and using the sugar as a base material for chemical industry and for fuel and food.
We did not see so clearly then, as we do now, that the large scale production of sugar-bearing crops need not be damaging to the soil or depleting of natural resources; the sugar (a carbohydrate) is made by the cane, or beet, from the components of the air already mentioned (carbon dioxide and water vapour) and the plant remains can be returned in their entirety to the soil from whence they came. There is thus, in principle, no 'sustainability' problem in growing sugar crops.
The essential point about the production of sugar for industrial and fuel use is that sugar can be fermented to make alcohol (and carbon dioxide) by age-old procedures. From huge amounts of sugar, grown sustainably, we can make huge amounts of alcohol (and, from it, huge amounts of ethylene too if required) These facts can be the basis of a 'saccharochemical' industry as varied and as flexible as the petrochemical industry has become.
What is more, alcohol can be used as motor fuel and as fuel for a variety of other purposes. So the agricultural/industrial fermentation production of alcohol can give us energy and chemical products essentially from the components of the air and when that alcohol is burned as fuel and when those chemical products are eventually finished with and incinerated, the carbon and hydrogen are returned to the air as carbon dioxide and water vapour to enable the cycle to be repeated ad infinitum. Alcohol, from sugar crops, is an essential link in this cycle.
With this cycle in mind, perhaps we can eventually match population, living reasonably well, with sustainable sugar production; if so, alcohol is going to be a boon for ever. It is worth a thought.
A sustainable high living standard globally is a goal to be scored - but perhaps at the price of shifting humanity's industrial 'centre of gravity' from the temperate to the tropical regions of the earth. Perhaps sugar cane could be grown intensively in the de-forested Amazon Basin while the northern lands can revert to the afforested state to become the planet's regulator and wildlife sanctuary and bio-diversity bank. Bring back the woolly rhino and the dear old mammoth!
One must hope that such a turn-about will not generate a self-righteous warring non-European imperialism . . . white inferiority . . . white slaves in the sugar plantations ..... the black man's burden and all that. Wanna bet?