The greenhouse effect can be observed not only on Earth but also on exoplanets similar to it. At some point, it can turn the world into hell. New modelling has found that this can happen almost instantly and has pointed to signs that it is happening.
Turning a planet into hell
A group of astronomers from the University of Geneva has confirmed long-standing suspicions that under certain conditions, the heating of the atmosphere of a planet like Earth due to the greenhouse effect can be rapid and irreversible.
The greenhouse effect is a phenomenon in which certain gases are formed in the planet’s atmosphere that prevent the normal passage of sunlight. Because of this, the heat energy of the sun that reaches the planet is not radiated back into space, but remains in the gas envelope and heats it up.
The gases that have the greatest impact on this effect are carbon dioxide and water vapour. As the temperature rises, more and more of the contents of the reservoirs become gaseous. The content of substances capable of trapping energy increases and the effect is amplified. As a result, the temperature is rising faster and faster.
Scientists have long warned that a rise in temperature of just a few tens of degrees can lead to a catastrophic jump. It could turn our planet into a Venus-like hell very quickly.
Clouds that forebode disaster
In the new study, scientists decided to model how an ordinary planet turns into hell. Previously, calculations of how the greenhouse effect should behave on exoplanets have already been carried out. However, those models reproduced the conditions under which it is negligible or at an average level.
The new modelling shows what happens when the amount of water vapour in the atmosphere is already close to critical. The study fully confirms the conclusion that once a certain value of this parameter is reached, the greenhouse effect cannot be stopped. After that, the planet really quickly turns into hell.
It was quite unexpected that at the beginning of this process, the nature of atmospheric convection and the distribution of clouds in the troposphere and stratosphere — its lower layers — changes. A strange inversion occurs, a characteristic pattern that can be clearly distinguished even on planets that are many light years away.
Scientists have studied it in detail and now claim that they can determine whether a planet is hell or habitable based on the results of observations from Earth. In addition, they plan to use the results of the study to analyze the situation on Earth.