Before I get to the description of energy sources, I want to shed some light on the significance of heat energy release by human civilization. You might encounter the claim that human thermal sources have a power four orders of magnitude lower than the power received by Earth from the Sun, and thus their impact on the climate is minimized. Similarly, the impact of human activities on the amount of water vapor in the atmosphere is downplayed, as I already mentioned in my first article “Reflections on the Problem of Global Warming.” Both of these claims are the biggest mistakes of the current theory of CO2 harmfulness.

The Earth represents a thermal system that maintains equilibrium in the long term. The Earth absorbs part of the energy from the Sun and simultaneously emits heat. The rate of heat emission through long-wave electromagnetic radiation depends on the fourth power of Earth’s absolute temperature. This means that if the Earth’s temperature slightly increases due to an imbalance between received and emitted heat, there will be a relatively higher increase in emitted heat by the Earth, and thermal equilibrium will be re-established. Thus, what matters is not the amount of solar energy received but the extent of the energy imbalance that occurs. In recent years, Earth’s energy imbalance (EEI) has reportedly doubled to 460 TW. This value cannot be easily measured or calculated. It may be, of course, subject to significant error. Nevertheless, let us consider it true for our reflections.

What is the thermal power of the entire human civilization? I found a reported power of 18 TW. What does this power consist of? The total power of produced electrical energy is said to be 3.5 TW. This energy turns into heat when used. The waste heat generated during electricity production is, overall, at least equal to the produced electrical energy, another 3.5 TW. The thermal output of the human body for all humanity is about 1 TW. Altogether, these figures alone account for 8 TW. To this, we must add the power of all heating systems for heating, the power of all transportation means driven by combustion engines, gas turbines, and nuclear power, the power of all manufacturing and technological processes where heat is released, such as in metallurgy. Also, the heat released by all agricultural production. Therefore, the total power of the entire human civilization can be considered approximately equal to 18 TW.

Let us now clarify the percentage by which human civilization contributes to Earth’s thermal imbalance. This share is 18/460=0.04. This means that the heat released by human civilization contributes to Earth’s energy imbalance by about 4%. Therefore, the power of human civilization is not negligible, as many climate activists claim. It is important to realize that this power of about 18 TW is produced by human civilization 24 hours a day, all over the planet, day and night. As I mentioned in the previous article, this has a fundamental impact on the amount of water vapor in the atmosphere, and thus on the greenhouse effect caused by water vapor. This is also confirmed by information about increasing average air humidity. I would like to remind once more that the basis of the current theory of CO2 harmfulness is a calculation from 1859, formulated by John Tyndall, expressing the dependence of atmospheric warming solely on the CO2 content in the atmosphere. Other influences are completely neglected as insignificant. However, since then, the Earth’s population has increased sixfold, and the thermal power of civilization has increased by an estimated fifteen times. I do not know whether the calculation was correct in 1859, but since it does not consider the influence of energy released by modern civilization, it cannot be valid today. It is evident that the current theory of CO2 harmfulness is burdened with a huge error. The primary problem of sustainability for human civilization is most likely its current size.

There is no doubt that civilization is characterized by increased energy consumption. I will allow myself an interjection. Astronomers and physicists are searching for extraterrestrial civilizations precisely by specific long-wave thermal radiation that civilizations should produce. They have also long designated the levels of civilization development according to the amount of energy a given civilization consumes (thus emits).

It is therefore astonishing that global warming is not in any way associated with the influence of the thermal power of human civilization, which is obviously dependent on the number of people and their energy consumption.

On the other hand, it is clear that Earth’s thermal system maintains thermal equilibrium on its own through increased heat radiation. Given the current size of civilization, a certain increase in the average temperature is simply inevitable and should not be surprising.

I will start with a bit of history of modern civilization and its energy. First, I would like to remind you that the development of human civilization is closely linked to the invention of heat engines, which provided humanity with energy for agriculture, industrial production, transportation, and all other civilizational advances. This fact has not changed and probably will not change for several more decades, and perhaps even centuries.

What are heat engines? I will try to list them sequentially based on their origin or spread. The Stirling engine, steam engine, Lenoir gas engine, Otto combustion engine, Diesel engine, steam turbine, gas turbine. These engines convert thermal energy into mechanical energy. When connected to an electric generator, this mechanical energy can be converted into electrical energy. Although it seems that a heat engine is a dirty word today, the vast majority of today’s civilization’s energy arises from the use of heat engines. All nuclear and thermal power plants use turbines for electricity generation. Most cars, ships, and aircraft are powered by heat engines. Similarly, most electrical energy that powers electric vehicles is obtained using heat engines.

The maximum efficiency of converting thermal energy into mechanical energy is theoretically limited by the highest achievable thermodynamic efficiency of the so-called Carnot cycle. For the efficiency of the Carnot cycle, the relationship η=1-T2/T1 applies. I will avoid a detailed explanation of this cycle. In practice, the conditions of this cycle cannot be met, and the efficiency of a real heat engine is always lower than the efficiency of the Carnot cycle. Just a brief remark. The temperature T1 (°K) is, for example, the input steam temperature into the turbine or combustion temperature in a piston engine. T2 (°K) is the output steam temperature from the turbine or the temperature of exhaust gases in a combustion engine. A heat engine has the potential to achieve higher efficiency with the lowest possible (T2/T1) ratio. This means with the highest possible temperature drop.

For real heat engines, the actual overall efficiency is typically below 50%. Care must be taken when comparing the efficiencies of heat engines. Overall efficiency should express the ratio of obtained mechanical energy to the supplied heat. It should be the product of thermodynamic efficiency and mechanical efficiency. Be careful, though; for example, with steam turbines, the manufacturer states the so-called internal thermodynamic efficiency. The actual thermodynamic efficiency of a turbine, however, is the product of internal thermal efficiency and the efficiency of the Carnot cycle. So if a steam turbine has a declared internal thermodynamic efficiency of 72%, the resulting actual thermodynamic efficiency is around 45% based on the temperatures in the circuit. The most efficient heat engines are large diesel engines (installed, for example, in ocean liners), which achieve overall efficiency over 50%. If we were to evaluate their efficiency as in turbines with the so-called internal thermal efficiency, we would achieve efficiencies over 80%.

For illustration, a steam engine had an overall efficiency typically around 12% and caused a great industrial revolution in the 19th century, and even in the 1970s, express steam locomotives were still running in the Czech Republic. It is essential to realize that we will not manage without heat engines in the future. As I mentioned above, this is not just about coal or gas power plants and combustion engines. Every modern nuclear power plant includes a steam turbine that converts the thermal energy generated by nuclear fission into mechanical energy. This is then converted into electrical energy in a generator. If we manage to master nuclear fusion in the future, the released thermal energy will likely also drive a steam turbine. Due to thermal efficiency, about half of the heat will always be sent directly or indirectly into the atmosphere. From the cooling towers of power plants, this heat is expelled into the atmosphere via water vapor, which is the most significant greenhouse gas. The produced electrical energy, once consumed, also turns into heat, warming the atmosphere.

I still owe climate activists and electric mobility enthusiasts my opinion on so-called renewable energy sources and electromobility. I will address this in more detail in the following (third) article.