Why Stephen Hawking warned humanity to leave Earth before it’s too late

Stephen Hawking was famous for his groundbreaking contributions to our understanding of black holes and the theory of general relativity. However, the renowned astrophysicist also frequently stressed the existential threats facing humanity. As a plausible solution, the cosmologist strongly recommended that humans begin colonizing other habitable planets.

The image shows Stephen Hawking in his specialized wheelchair on October 10, 1979.

Hawking believed that humans have been putting all their eggs in one basket—Earth. With rapid technological advances and a changing climate, the renowned scientist warned that humanity might fall victim to a catastrophic event that could wipe out our entire species. Convinced that a global doomsday was inevitable sooner or later, Hawking urged humans to find an alternative planet to sustain our race in the long run.

The image is a 3D render stock photo of an astronaut standing on an alien exoplanet.

Hawking's warnings were grounded in statistical probability. He clarified that while the risk of an apocalyptic catastrophe in any given year is low, the probability adds up, becoming a near-certainty in the next 1,000 to 10,000 years. Pointing to the specific crises Earth might face, the cosmologist highlighted asteroid strikes, nuclear warfare, artificial intelligence, and GM viruses.

Hawking told the BBC in 2016, “We will not establish self-sustaining colonies in space for at least the next hundred years, so we have to be very careful in this period."

The image is an illustration of a close-up debris cloud around a star named HD 166191.

Interestingly, Hawking was not alone in pushing for planetary colonization. Aerospace entrepreneur Elon Musk echoed a similar narrative. During a 2013 conference, Musk said, “Either we spread Earth to other planets, or we risk going extinct. An extinction event is inevitable, and we're increasingly doing ourselves in." Today, Musk’s SpaceX is actively preparing for a mission to colonize Mars.

The image is an artist’s concept art showing humans setting up their habitats on Mars.

Trying to put his thoughts into practical application, Hawking backed an ambitious interstellar travel project called the Breakthrough Starshot Initiative. Announced in 2016 by billionaire Yuri Milner, the project aimed to launch human technology to our nearest star system, Alpha Centauri. However, despite generating a lot of initial noise, a decade later, little is known about the project’s current status.

The image shows Stephen Hawking during ‘The Information Paradox for Black Holes’ media event dated July 21, 2004.

Hawking also acknowledged the rapid advances made in the field of artificial intelligence; in fact, his own communication technology utilized a basic form of integrated AI. However, the visionary scientist was deeply wary of how advanced artificial intelligence might eventually threaten humankind.

In a 2014 interview with the BBC, Hawking said, “The development of full artificial intelligence could spell the end of the human race.”

The abstract image is of a humanoid robot staring at our blue planet from a space station.

Beyond artificial intelligence, the Cambridge physicist also considered global warming to be one of the greatest existential threats to humanity. He feared that our blue planet might reach a tipping point from which reversing the greenhouse effect would be impossible.

Reflecting on the United States’ decision to pull out of the Paris Agreement, Hawking told the BBC in 2017, “Trump's action could push the Earth over the brink, to become like Venus, with a temperature of 250 degrees, and raining sulphuric acid.”

The image shows a magnified view of cracked soil, possibly experiencing drought-like conditions.

When it came to humanity's attempts to search for extraterrestrial life, Hawking had a stark warning. He believed that if an advanced alien civilization came to Earth, they would probably raid our resources and leave. Speaking to the Discovery Channel in 2010, the cosmologist said, “We only have to look at ourselves to see how intelligent life might develop into something we wouldn't want to meet."

The image depicts a scene from the 1956 movie, Earth vs. Flying Saucers, where an alien can be seen standing.