The science of climate change

A simple definition of sustainable energy is that it is a clean system


A simple definition of sustainable energy is that it is a clean system, which satisfies the needs of the present generation without affecting the future generation adversely

In a developing country, it is important to realise that sustainable development covers the following interrelated aspects: ecology, economics, politics and culture. Renewable energy, on the other hand, is renewed naturally within a relatively short space of time, such as solar energy (photovoltaic generation and thermal heating); wind power (windmills and wind turbines); hydropower (still the cheapest if available); wave power (very expensive); bio-energy (limited application); and geothermal (not found in southern Africa but in East Africa).

Choice of power

According to Demand Side Management (DSM), the cheapest source of energy is not to use it at all. Switching off all the electricity you do not use will not only reduce your electricity bill but also help to extend the availability of this valuable resource at a national level.

A case-in-point is the use of domestic hot water cylinders, commonly called geysers in South Africa. Why do some installers still set the control temperature of a geyser at 70oC, when humans can only tolerate a shower below 41oC? To make matters worse, geysers often remain switched on continuously, instead of just for the time when hot water is required. Luckily, Eskom is implementing a strategy where geyser temperatures are kept at 55oC to ensure that warm-water-liking bacteria are kept in check at the prescribed temperature.

The science of climate change

Being part of nature, climate change is subject to worldwide natural cyclic changes with or without humans. As part of nature, the growth of the human population since about 1850 and the expected influence of rapid growth of adverse climatic influences like CO2 trapped in the atmosphere, show a perfect golf-stick correlation even up to 2050. Journalists and politicians did an incredible job in creating a global awareness of the possible environmental threats facing us, but seem to overlook the threatening cause of ever-increasing populations.

Over 70 nations signed the Paris Accord ensuring that governments will do their best to curb the rising temperature below 2oC within half a century or so. Can we blame President Donald Trump for asking to be given hard facts before signing this agreement? He obviously did not want to follow his predecessor, who signed this agreement, whilst also signing more environmentally-damaging oil sales contracts than any politician of his time.

Trump should be forgiven, since the terrible acid rain, which I experienced in Germany in the 70s, was said to be due to oxides of sulphur and nitrogen released from burning coal and petroleum fuels. Motor vehicles were blamed until botanists eventually explained that these trees were actually diseased.

A decade later, I was shaken by further alleged damaging effects of cars possibly causing the ozone hole. By 1996, CFC aerosols were phased out. But my naïve question remained: “Why was the largest hole over Africa when far more motor vehicles were registered in the Americas and Europe?”

To this day, no convincing answer has been found, in spite of the Brewer-Dobson Prevailing Stratospheric wind patterns. Another interesting fact is that a meteorite apparently struck earth some 300 years ago and peeled the earth entirely of its protective ozone layer. It recovered entirely on its own within a few years.

A lesson to be learnt

Scientists usually follow the rule of cause and effect but we should be warned of blind projections into the future, based on shaky evidence like:

Why is it assumed that the entire globe is affected only by the

Arctic—where ice is melting—and the much closer Antarctic—where more snow is piling up annually, preventing ships from reaching their previous destinations—is completely disregarded?

Based on the claims by Heartland:

  • Climatologists are terrible at predicting temperatures.
  • Predictions of extreme weather events and sea level rises have failed to be true.
  • Models cannot account for inexplicable deviations/cooling periods
  • It is not clear whether the widely used data is accurate—Only data that fits a particular model is used, but the major predictor for weather [water vapour] is being disregarded.
  • A slightly warmer climate may be advantageous to certain regions—think of our vegetation, crops, tourism, etc.
  • Scientists will develop competitive cheap, clean energy anyhow.

Choice of energy sources

South Africa is blessed to be ableto choose from a range of possible energy sources to be utilised on a local or regional basis. Let us not listen to politicians and journalists, specialising in global warming. Energy decisions by themselves are dangerous without doing a proper economically-sound costing exercise before attempting projections into the future. Capital outlay, long-term running and maintenance costs, and labour need to be included before comparisons can be made. A colleague in Kenya once remarked that most African languages do not have a word for ‘maintenance’. So, ensure that imported rules and policies concerning advanced technical fields (like nuclear) are observed. Our municipalities are frequently guilty of poor maintenance.


South Africa’s estimated coal reserves will last almost twice as long as the global coal reserves. Thus, what should this developing country do? Some environmentalists say that coal should remain in the ground; uninformed economists say that it could be exported to Japan or China as raw material for a ‘quick buck’; but forward-thinking engineers say: “Let us rather clean up our processes and manufacture electricity or other products like fuel, from coal.”

Let us see what and when other competitive options of power generation become viable in South Africa. We should remember that our government cannot spend large sums of money to subsidise renewable energy, like most overseas countries have done. We have a coal-based economy. At this stage, over 90% of South Africa’s electricity (ie. over 40 000 MW) is still produced from coal. According to the Paris Accord, which South Africa signed, the plans are to significantly reduce our carbon footprint, favouring other primary sources of energy. The updated IRP 2016 report promotes cleaner sources of energy, possibly also allowing fracking to stimulate our gas industry.

Nuclear power

As a Nuclear Scientist, I was biased towards the environmentally-clean, relatively cheap-to-run, technology, especially since we can mine Uranium (and could enrich it) in South Africa. But governments have been ‘dilly-dallying’ for so long that we can probably no longer afford it. Although nuclear has a good safety record without a mishap in France—with 66 nuclear plants—and in South Africa, the fear of a natural disaster as in Japan, persists. Russia experienced the Chernobyl disaster, because of political interference. We must guard against attempting to run nuclear plants by incompetent, politically-favoured individuals. Germany made the mistake to phase out nuclear power too suddenly. The drive to sustainable energy cost them much more than anticipated. Areas that were normally fed with electricity now became generators of seasonal wind power and so forth. To solve their problems, industry now has to spend billions of Euros to restructure their distribution infrastructure.

Renewable energy

The Renewable Energy Independent Power Producers’ Programme’s target for wind power was 1850MW and PV solar, 1450MW. At present, only 600MW wind-based and 1000MW PV solar are fed into Eskom’s national grid, which could by 2020 rise to 6900MW and 6694MW respectively, or just over 10% of the grid.

Stakeholders need to ask the following relevant questions:

  • Why is my source viable?
  • When is it viable?
  • Where is it competitive?
  • How viable is it now?
  • How sustainable will it be in future?

Of particular interest to us should be the ‘thermal solar plants’ near Pofadder (100MW) and Upington in the Northern Cape, where these new but still more expensive plants with parabolic mirrors use solar-heated salt to drive turbines—even for a few hours after the sun has set.

This gives the thermal solar plants the unique advantage over other renewable energy sources, to generate electricity even after its primary source (the sun in this case) is no longer available.

Although sustainable energy has become a buzzword, it is not scientifically advisable to blindly follow the whims of environmentalists, politicians and journalists. Energy decisions and policies are often meaningless if not based on defensible, accountable economic facts. The worst case scenario is a projection based on questionable basic data. 

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Issue 413


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