Abstract The significance of greenhouse gases for climate change is assessed in the case of carbon dioxide on the basis of thermodynamic data. According to the values of the molar heat capacity, no increased heat-storing property of this greenhouse gas can be determined. The absorption and desorption of infrared radiation by the greenhouse gases is seen as a reversible dynamic process, which on the one hand reduces the IR radiation from the Sun, and on the other hand, delays the re-radiation from the Earth. As converters of heat into IR photons and vice versa, the greenhouse gases play an important role in balancing the radiation. The direction of heat transport in the atmosphere is determined by the 2nd Law of Thermodynamics. The range of IR radiation is determined according to the gradation of air pressure in the atmosphere.