When will Earth become uninhabitable?

Over the centuries there have been many attempts to predict the death of our planet; fortunately, it's all nonsense.


Asked by: Lizzie Barnett, Kent

Over the centuries there have been many attempts to predict the death of our planet. Even Isaac Newton tried, allegedly predicting the end of the world in 2060; fortunately, like his scripture-based methods, it’s nonsense.

But the idea that we’ve got until the Sun runs out of nuclear fuel over five billion years from now is also a myth. According to astronomers, the Sun is destined to turn into a huge, glowing red giant star, potentially engulfing the Earth in the process. But long before that, the extra heat striking our planet will trigger the evaporation of sea water. That will drive up atmospheric levels of water vapour – a far more potent source of global warming even than CO2. And that, in turn, will make the Earth even hotter, leading to catastrophic ‘runaway’ heating that eventually evaporates the oceans.

Simple computer models initially suggested this disaster could render our planet inhospitable in as little as 150 million years from now. But late last year the journal Nature published a much more sophisticated simulation by a team from the Laboratory for Dynamic Meteorology in Paris, and this suggests we have got at least a billion years before this apocalypse.

Read more:

Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun science facts.