Stephen Hawking says that US President Donald Trump's decision to pull out of the Paris climate agreement could lead to irreversible climate change. Stephen Hawking says that US President Donald Trump's decision to pull out of the Paris climate agreement could lead to irreversible climate change. Prof Hawking said the action could put Earth onto a path that turns it into a hothouse planet like Venus. He also feared aggression was "inbuilt" in humans and that our best hope of survival was to live on other planets.

The Cambridge professor spoke exclusively to BBC News to coincide with his 75th birthday celebrations.

Arguably the world's most famous scientist, Prof Hawking has had motor neurone disease for most of his adult life. It has impaired his movement and ability to speak.

Yet through it all, he emerged as one of the greatest minds of our time. His theories on black holes and the origin of the Universe have transformed our understanding of the cosmos.

China and U.S....

(Media / China and U.S. Agree to Cut Down Carbon Emissions)