The Earth without Greenhouse Gases
2 hours ago
By Andy May
The overall greenhouse effect (GHE) is often defined as the difference between Earth’s average global temperature without greenhouse gases (GHGs) and with them. Greenhouse gases are all the gases that absorb some portion of the thermal energy emitted by Earth’s surface. The most important of these gases is water vapor, but there are minor GHGs like CO2, ozone, and methane.
The calculation of Earth’s temperature without GHGs is usually done by unwrapping the planetary sphere and placing it in space at the average distance of the Earth from the Sun and having the whole of Earth’s surface illuminated by the Sun with one-fourth of the Sun’s power to account for the spherical Earth and the fact that half of Earth is always dark. This imaginary flat Earth does not rotate, and no part of it is ever dark. A description of the calculation can be read in Benestad, 2017. The global average temperature calculated with this scenario is around 255K (-18°C) and since this is about 33°C less than the current global average temperature of 15°C, the overall greenhouse effect is assumed to be about 33°C. Further discussion of this definition can be seen here.
In this post I will first list the problems with this “flat Earth” GHE model, then provide a model of a new GHG-free spherical rotating Earth. After this, I will list the assumptions used to create the spherical Earth model, the problems with it, and finally discuss what we learned making the model. Computer models are learning tools, they never give you a correct answer, but they do help you learn about the problems they were designed to investigate.
https://wattsupwiththat.com/2025/03/16/the-earth-without-greenhouse-gases/
