Demonstrating the Reverse Greenhouse Effect in the Laboratory – PART1
6 hours ago Anthony Watts
Editorial note: WUWT is publishing this paper as a contribution to open technical discussion, not as an endorsed or settled account of atmospheric physics. Readers should distinguish between the paper’s narrow laboratory claim—that IR-active gases can contribute measurable radiative effects under the conditions of this apparatus—and its much broader inferences about climate sensitivity, water-vapor feedback, Antarctica, and the relative role of CO2 in the real atmosphere. Those larger extrapolations remain contested, and this experiment by itself does not resolve them.- Anthony
Demonstrating the Reverse Greenhouse Effect in the Laboratory – Part 1 (Part 2 will be published tomorrow)
Hermann Harde, Michael Schnell
Abstract
We present first quantitative studies demonstrating and using the principle of the reverse or so-called negative Greenhouse-Effect (GH-effect). The common GH-effect is running backwards, when air is warmer than a solid body with which it exchanges Infrared (IR) radiation. In this case, Greenhouse Gases (GH-gases) contribute to cooling of the air and to an increase in the outgoing IR radiation, which is detected by sensors on a cooled plate. With a series of laboratory experiments, it is shown that the IR radiation of GH-gases is not an “ominous” phenomenon but quite real and can be verified also under regular pressure conditions. The results were recently published in the journal Science of Climate Change [1] and are presented here in a slightly shortened, easy-to-understand form. Since the investigations are quite extensive, the studies are divided into two parts.
In this first part we consider some theoretical aspects of general interest: Why is the much stronger CO2 band of 4.3 μm compared to the 15 μm band, insignificant for heat transport, why is water vapor the dominant greenhouse gas, and why is in a laboratory experiment – like an iceberg – only seen the tip of the gas radiation.
We explain how the negative GH-effect in Antarctica contributes to cooling of the planet. We also support the thesis that the temperature of the water planet Earth is mainly determined by evaporation, convection and cloud cover and not by infrared radiation.
In addition, the general concept of experimental investigations and initial tests with the new apparatus are presented. It turns out that the experimental set-up can also detect water vapor radiation, which was not possible in our previous studies [2]. This opens up new perspectives for investigating the superposition of water vapor radiation with that of other greenhouse gases.
https://wattsupwiththat.com/2026/04/05/demonstrating-the-reverse-greenhouse-effect-in-the-laboratory/
