Eike Roth 

The greenhouse effect is the warming of the earth's surface due to the presence of greenhouse gases in the atmosphere. It is said to be 33 °C, but we cannot measure this value because we cannot create the state “without greenhouse gases”. We therefore have to rely on calculations, although these are controversial. In the climate debate, this lack of measurements is often denoted as a major shortcoming. As a remedy, a novel model is proposed here, which proves the fundamental existence of the greenhouse effect beyond doubt, and which makes it possible to determine its real size from well-known measurements. Additionally, this model makes it possible to reject some other arguments against the greenhouse effect in a better way, such as an alleged contradiction to the 2nd Law of Thermodynamics, or an allegedly far too low concentration of greenhouse gases.
This model consists of a row of bodies, the first one heated, the last one cooled, those between freely adjusting their temperatures. When an additional body is inserted into that row, a temperature spread develops in it, so that the body before the new one must warm up by half of this spread and that behind it must cool down accordingly. Applied to the earth, the temperature of the earth’s surface is warmer with greenhouse gases in the atmosphere than without by half of the temperature spread in the atmosphere. This value is well-known and confirms the 33 °C cited above for the “natural greenhouse effect” surprisingly well. The weakness of the model is that it is too coarse to make a statement about the increase of the greenhouse effect when the CO2 concentration is enhanced (“additional greenhouse effect”). Lessons learned, limits, related problems, and open questions are discussed.