From Armageddon to The Day After Tomorrow, there have been plenty of Hollywood movies about how our world might end.
Now, a study has provided a terrifying glimpse into our planet’s future, and it doesn’t look pretty.
The researchers simulated a “runaway greenhouse effect” – a dramatic spike in temperatures on our planet.
Worryingly, they say Earth could soon become an “uninhabitable hell”, just like our neighboring planet, Venus.
We don’t have to look very far into the future to reach that point, scientists predict A runaway greenhouse effect on Earth could be only a few hundred years away Or even sooner.
The new study was led by astronomers at the University of Geneva (UNIGE), along with the French CNRS laboratories in Paris and Bordeaux.
They warn of “evaporation of the entire surface ocean” of the Earth and a “dramatic increase in global surface temperatures.”
“This climatically unstable transition separates two groups of planets – temperate planets and hot planets after escape,” they say in their paper.
“This is one of several scenarios aimed at explaining the difference between Earth and the beginning of Venus.
“Understanding the runaway greenhouse effect is pivotal to assessing the different evolution of Venus and Earth.”
Venus is known as Earth’s “evil twin” because it is also rocky and about the same size, but its average surface temperature is 870 degrees Fahrenheit (465 degrees Celsius).
Thanks to its dense atmosphere, Venus is hotter than Mercury, even though the latter orbits closer to the Sun.
The ball of rock is not only uninhabitable, but also sterile, as its surface is hot enough to melt lead and toxic clouds of sulfuric acid.
Even from Earth, Venus is the brightest thing in the night sky other than the Moon, and can be distinguished by a slight yellow hue.
In this way, it serves as a clear warning to Earthlings about what could happen to a planet.
Although gases like carbon dioxide and methane are known to cause global warming, the study authors say a runaway greenhouse effect on Earth could actually be caused by water vapor.
The world is already warming due to carbon dioxide and methane emissions, and this is producing more water vapor in the atmosphere, due to ocean evaporation.
Although many people don’t know it, water vapor is a natural greenhouse gas.
Water vapor prevents solar radiation absorbed by Earth from returning toward the vacuum of space, because it traps heat “like a rescue blanket.”
The greenhouse effect increases ocean evaporation, thereby increasing the amount of water vapor in the atmosphere – a rapidly rising catastrophic spiral.
“There is a critical threshold for this amount of water vapor, beyond which the planet cannot cool anymore,” said lead author Guillaume Chaverot from UNIGE.
“From there, everything is carried away until the oceans have completely evaporated and the temperature reaches several hundred degrees.”
With new climate models, scientists have calculated that a very small increase in solar radiation will lead to an increase in global Earth’s temperature of only a few tens of degrees.
They claim that this would be enough to trigger this irreversible runaway process on Earth and make our planet as inhospitable as Venus.
The researchers have identified a three-part process, which they say can be applied to any planet with oceans, even those outside our solar system (known as exoplanets).
First, assuming that the ocean surface is initially liquid, there is an evaporation phase that enriches the atmosphere with water vapor.
Second, when the ocean is considered completely evaporated, there is a “dry transition” during which the surface temperature rises dramatically.
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Finally, evolution ends in a hot, stable “post-escape state,” which is what Venus has been in for the past 700 million years, experts estimate.
The team’s research also highlights the importance of information about exoplanetary temperatures, as determined by powerful satellites and telescopes, for determining where aliens exist outside our solar system.
If the exoplanet were very hot, it would likely have conditions similar to Venus and be less able to harbor life.
“By studying the climate on other planets, one of our strongest motivations is to determine their ability to host life,” said study author Emmeline Polmont from UNIGE.
The results were published in the journal Astronomy and astrophysics.
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