Earth could turn into a hothouse planet like Venus, with boiling oceans and acid rain, if humans don't curb irreversible climate change, physicist Stephen Hawking claimed in a recent interview.

“We are close to the tipping point, where global warming becomes irreversible. Trump's action could push the Earth over the brink, to become like Venus, with a temperature of 250 degrees [Celsius], and raining sulfuric acid,” he told BBC News, referring to the president's decision to pull the U.S. out of the Paris climate deal.

But most climate experts say that scenario is a dramatic and implausible exaggeration: Relative to Venus, planet Earth is much farther from the sun and given its chemical makeup will never have such a thick carbon dioxide atmosphere, so it could not likely reach temperatures of 482 degrees Fahrenheit(250 degrees C) that Hawking described in the interview, they say. 

However, the general trend of runaway and catastrophic climate change is a real concern, experts said. “Hawking is taking some rhetorical license here”, Michael Mann, a climate scientist at the Pennsylvania State University, told Live Science in an email. “Earth is further away from the sun than Venus and likely cannot experience a runaway greenhouse effect in the same sense as Venus — i.e. a literal boiling away of the oceans. However, Hawking's larger point —that we could render the planet largely uninhabitable for human civilization if we do not act to avert dangerous climate change — is certainly valid.”

Venus is the second planet from the sun and the brightest planet in the solar system. Despite being the same size as Earth and having roughly the same gravity as our home planet, it's a far cry from our water-drenched planet. Venus is the hottest planet in the solar system, with temperatures reaching 870 degrees F (466 degrees C). The reason for these sweltering temperatures is Venus' thick carbon-dioxide atmosphere that is dotted with sulfuric acid clouds; the atmosphere traps much more heat than our own does. It is also much closer to the sun, meaning it absorbs much more solar radiation than Earth.

The leading theory about how Venus came to be such a hellscape is that the planet got caught in a feedback loop, wherein the planet absorbed more solar radiation than it released, causing more water vapor to get trapped in its atmosphere. That, in turn, led to greater heat absorption, and runaway greenhouse effect.

Though most humans take for granted the relative constancy of an Earth-like climate, our planet has undergone dramatic changes in its 4.5-billion-year history. So, it's not unreasonable to contemplate the possibility of a runaway climate scenario. Still, most experts see that possibility as incredibly unlikely.

While in theory, a process similar to the one experienced on Venus could take place on Earth, the process would most likely occur over hundreds of millions of years, most experts believe. There are also very low odds that Earth's oceans could literally boil away like Venus' primeval oceans did. Earth, meanwhile, is protected from solar radiation by an atmosphere that is dramatically different from that of Venus.

(Adapted from https://www.livescience.com/59693-could-earth-turn-into-venus. – Access on 07/28/20) 

Glossary: 

1. sweltering - extremamente quente.

The text states that