Professor Stephen Hawking, who has died aged 76, was clearly an intelligent man - but he was also extremely witty, able to laugh at himself and a huge fan of pop culture.

But, being a clever man, he knew that life is a bit more than a 'box of chocolates'. He repeatedly made predictions about how and when the world will come to an end.

Cambridge News has put together a list of his top five theories about how and when mankind will face its doom.

From Artificial Intelligence to nuclear war, it seems there is no end to the apocalyptic threats facing humanity.

And given that Professor Hawking was one of the most celebrated scientists of his generation, it might be worth heeding his warnings.

Stephen Hawking's five doomsday prophecies

1. Death by fireball

We're all going to die in less than 600 years when the Earth is so overpopulated our energy consumption will make the planet burn red .

Prof Hawking was speaking at a Tencent WE Summit Beijing in November, where scientists meet from all over the world to share ideas.

He was reported as saying: "By the year 2600, the world’s population would be standing shoulder to shoulder, and the electricity consumption would make the Earth glow red-hot.”

To save itself, mankind must take a cue from American TV series Star Trek and “boldly go where no one has gone before,” he said in the appearance, and develop the technology to travel at the speed of light.

2. Robots will take over the world

This year Professor Hawking expressed his fear that artificial intelligence will replace humans .

Speaking in an interview to Wired.co.uk he said: "We need to move forward on artificial intelligence development but we also need to be mindful of its very real dangers.

"I fear that AI may replace humans altogether. If people design computer viruses, someone will design AI that replicates itself.

"This will be a new form of life that will outperform humans."

3. Human aggression and nuclear technology will kill us in the end

Speaking to the BBC as part of his 75th birthday celebrations he said: "I fear evolution has inbuilt greed and aggression to the human genome.

"There is no sign of conflict lessening, and the development of militarised 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."

4. We need to find another planet to live on within 100 years

Professor Hawking said we need to explore our technological capabilities to the fullest in order to avoid extinction.

If we do not find another planet to live on , climate change, over population, pandemics and our warring ways will get us in the end.

This was explored in this year's BBC Two documentary 'Expedition New Earth' , in which the professor enlisted engineering expert Christophe Galfard to explore the feasibility to interplanetary travel.

In his interview with Wired he also said he believed the planet had "reached the point of no return".

5. Donald Trump

The professor did not shy away from criticising US president Donald Trump .

When the president announced he would not be signing the Paris climate change agreement, which aims to tackle the threat of global warming Hawking was among his most vocal opponents.

Speaking to the BBC during his birthday celebrations in July, Hawking warned Trump’s decision to withdraw would “push the Earth over the brink”.

He said: “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 sulphuric acid.

"Climate change is one of the great dangers we face, and it's one we can prevent if we act now.

"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."