Heat has a harder time escaping into space when more greenhouse gases are emitted into the atmosphere. This raises the temperature of the planet and may even lead to the emission of additional greenhouse gasses. The possibility of this runaway greenhouse gas effect occurring has finally been identified by researchers, and it poses a serious threat to worlds like Earth.

Water vapor has the potential to accelerate the runaway greenhouse gas effect and effectively boil worlds like Earth alive, according to new study by astronomers at the University of Geneve (UNIGE) and CNRS laboratories in Paris and Bordeaux.

It serves as a sobering reminder of how dire a future with human-caused climate change can seem, but it is one that must be issued if we are to prevent this from happening. According to the research team, a planet’s cloud cover, atmosphere, and structural makeup all change completely when its climate transition reaches its final stages. They claim that if a runaway effect were to occur, it may be challenging to stop it.

Of course, the worry is that a runaway greenhouse gas effect like this might effectively turn Earth and other planets into Venus-like bodies, trapping heat that ordinarily escapes the planet’s atmosphere. Naturally, this would only lead to the release of more greenhouse gases. Based on these new calculations, water vapor may rank among the planet’s most harmful gases, according to the researchers.

Although there are many different kinds of greenhouse gases, water vapor is particularly difficult to regulate. As temperatures rise worldwide, more water vapor may be released into the atmosphere, effectively acting as a blanket to trap heat inside. If it were to occur on Earth, surface temperatures would rise to about 1,800 degrees Fahrenheit. That is hotter than the temperatures on Venus, Earth’s evil twin, and hot enough to melt lead.

Though it’s a horrifying idea, studies such as this can help us comprehend the dangers of allowing climate change to get out of control. While some have suggested solutions to slow down climate change, such as space bubbles, if we can’t contain a greenhouse gas effect that is out of control, our planet may wind up looking a lot like its evil twin, which won’t be beneficial for anyone.