Theoretical physicist Stephen Hawking warned recently that Donald Trump's dramatic shift away from science-based policies to pander to his lowest-common denominator base "could push the Earth over the brink."

In an interview for his 75th birthday, Hawking told the BBC that he was troubled by Trump's decision to exit the Paris Climate Accord.

"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 two hundred and fifty degrees, and raining sulfuric acid," the professor explained. "Climate change is one of the great dangers we face, and it's one we can prevent if we act now."

He added: "By denying the evidence for climate change, and pulling out of the Paris Climate Agreement, Donald Trump will cause avoidable environmental damage to our beautiful planet, endangering the natural world, for us and our children."

Regardless of Trump's actions, Hawking said that humans are destined to leave the planet if the species wants to survive.

"I fear evolution has inbuilt greed and aggression to the human genome," he observed. "There is no sign of conflict lessening, and the development of militarized technology and weapons of mass destruction could make that disastrous. The best hope for the survival of the human race might be independent colonies in space."