The earth is heating up faster than scientists expected. When the greenhouse effect is out of control, the earth will become an uninhabitable hell for humans. Recently, astronomers from the University of Geneva simulated for the first time the runaway stage of the Earth’s greenhouse effect. Eventually, the Earth’s oceans will all evaporate, the temperature will rise sharply, and the planet will transform from a temperate planet to a thermally runaway planet.
Venus is nicknamed Earth’s evil twin because it is also made of rock and is roughly the same size. The only difference is temperature. Earth has oceans and life, but Venus is a barren, sulfur planet and the hottest planet in the solar system, with surface temperatures as high as 500°C.
Advertisement (Please continue reading this article)
But if the earth’s greenhouse effect gets out of control, it is likely that it will become the second planet in less than a few hundred years. A team of astronomers from the University of Geneva and the French National Center for Scientific Research recently published a study in the Review of Astronomy and Astrophysics, using a 3D global climate model to study how the climate and atmosphere will evolve if the earth’s temperature is out of control.
As long as a slight increase in solar radiation causes the global earth temperature to rise by a few dozen degrees, the planet will transform from an Earth-like temperate and habitable state to a hell with a surface temperature of 1,000°C. Researchers have discovered changes in cloud structure. In the initial stage of temperature rise, the atmospheric structure and cloud range undergo significant changes, leading to an almost irreversible and very complex runaway greenhouse effect.
Water vapor is the key to loss of control
Advertisement (Please continue reading this article)
While gases like carbon dioxide and methane are known to contribute to global warming, the runaway greenhouse effect may be triggered by water vapor. Water vapor is a natural greenhouse gas, and the low-temperature greenhouse effect is useful. Without the greenhouse effect, the average temperature of the earth would be below the freezing point and become a sphere covered with ice and snow. But too much of this effect will increase ocean evaporation and increase atmospheric water vapor. Water vapor covers the earth like a blanket, absorbing more heat.
Scientists say there is a critical threshold for water vapor content above which the Earth can no longer cool until the oceans completely evaporate. This is a catastrophic, rapidly escalating spiral.
Ocean evaporation temperatures rise sharply
Scientists have calculated that, assuming the runaway process begins on Earth, the evaporation of just 10 meters of the ocean surface will cause the surface pressure to increase by 1 bar. Within just a few hundred years, the Earth’s temperature will reach over 500°C, followed by surface pressure reaching 273 bar and temperatures exceeding 1,500°C, by which time the oceans will have completely evaporated.
The researchers outline three main processes that could be applied to any planet with an ocean, even outside the solar system. Initially a liquid ocean in the evaporation stage, the atmosphere is rich in water vapor. Next, the ocean completely evaporates, a drying transition stage occurs, and the surface temperature rises sharply. Finally, the evolution ended in a hot and stable “post-runaway state,” which experts estimate has been the state of Venus for more than 700 million years.
Climate scientists warn that if the earth’s average temperature rises by more than 1.5°C compared with pre-industrial times, there is a risk of uncontrollable climate change. Although the current state is different from the runaway greenhouse simulated by scientists, it also warns that the earth is not far away from the “doomsday”.
(Source of first image:Pixabay)
