**5. Conclusions**

Total energy produced by our civilization on the Earth consists of the useful energy (electricity, mechanical energy, etc.) and heat, as an adverse side e ffect. Unfortunately, the various types of useful energy are finally converted to heat in machines, vehicles, and devices. The estimated calculations presented in this work prove that the total power produced by us was 0.0414% in 2000 and 0.0577% in 2017 of the global solar power reaching the Earth's surface—it means reaching the lowest layers of the atmosphere, almost the ground. A significant increase in the "*n*" factor between 2000 and 2017 results from the increase in global energy production.

A few questions arise here—are these values high or low? Are they important? A very good determiner of the importance of these values is the value of cyclic, annual changes of the Earth's orbit. The orbits of planets are not circles; they are ellipses. The eccentricity of planets is a very well-known natural phenomenon in the solar system. As a result of the elliptical trajectory of the Earth around the Sun, the solar light power density varies about 3.3% [11], and that is over 50 times more than the "*n*" factor in Table 1. After inserting data into Equation (20), the total heat produced on the Earth causes an effect like a seeming shortening of the radius of the Earth's orbit around the Sun by about 31,000 km in the year 2000, and about 43,300 km in the year 2017. Consequently, the seeming radius shortening ("*s*" in Equation (5), Figure 8) is about 2.4 (for 2000) and 3.4 (for 2017) times bigger in comparison to the Earth's diameter (12,756 km). These distances are significant compared to the Earth's dimensions, but, in the field of astronomy, they are very small. Taking into account that the average Earth-Sun distance is about 1496 × 10<sup>5</sup> km, the seeming shortening "*s*" is 3455 times smaller (in 2017). However, the key factor in assessing the importance of the heat emitted during the global energy production in terms of climate impact is the comparison of the parameter "*n*" to the natural changes of the solar light power density reaching the Earth. That power density varies about 3.3% cyclically during every year (the "*n*" is about 50 times smaller), and this is why the total heat energy produced by our civilization has a small impact on the global warming in the time horizon of several dozen years. We can say that there would be a one-year increase of supplied energy by about 3.3% of the average solar energy once every 50 years. It would probably have significance over several hundred years. Therefore, the use of renewable energy sources makes sense regardless of their energy e fficiency because the emitted heat during the generation of electric power in such sources does not significantly a ffect the climate. For example, photovoltaic solar cells have a low energy e fficiency—a dozen or so percent [28]. The fact that more than 80% of solar energy is converted into heat in photovoltaic panels should not be a limitation in their widespread use.

**Author Contributions:** Conceptualization, A.M. and A.N.; Methodology, A.M. and A.N.; Validation, A.M. and A.N.; Formal Analysis, A.M. and A.N.; Investigation, A.M. and A.N.; Resources, A.M. and A.N.; Data Curation, A.M. and A.N.; Writing—Original Draft Preparation, M.A. and A.N.; Writing—Review & Editing, M.A. and A.N.; Visualization, A.M. and A.N.; Supervision, A.M.; Project Administration, A.M.; Funding Acquisition, A.M.

**Funding:** This research received no external funding.

**Conflicts of Interest:** The authors declare no conflict of interest.
