What the heck actually happens to Earth in Doctor Who?

Exactly what happened to our planet to transform it into an uninhabitable wasteland inhabited by the Dregs is never clarified, though a brief telepathic communication between the Doctor and a Dreg shows us brief, flashing images of devastation and explosions (likely nuclear). Those maniacs. They blew it up.

Barely escaping from Orphan 55 alive, the Doctor later assures the TARDIS team that this is only "one possible future" but lectures them on the dangers of indifference and allowing Earth to continue heading down a dangerous path.

"People can save planets, or wreck them – that's the choice," she chides. Be the best of humanity, or..." – Dregs!!

The fate of Earth as seen in Orphan 55, though, is but one of many that Doctor Who has forecast across its more-than-56 years on screen. Few of its predictions, though, are positive...

Gird your loins, because according to Doctor Who we're really in for it over the next 40 or so years: as established by 2008 episode The Waters of Mars, Earth will suffer from "chaos" including climate change, ozone degradation and something called the "oil apocalypse", while 2014's Kill the Moon revealed that the increased weight of the Moon will also cause severe tidal issues.

But there was a threat facing Earth worse than all of that... the Daleks!

In the 22nd century, there was a Dalek invasion of Earth (as seen in... erm... 1964's The Dalek Invasion of Earth) and the human race was brought to its knees: whole continents - Africa, Asia and South America - were almost entirely wiped out, while many more cities across the world - including New York - were destroyed. It took the efforts of the first Doctor (William Hartnell) and is companions to free Earth from the Daleks' tyrannical suckers.

All was well until the 29th century, when Earth's environment was all but destroyed by solar flares, forcing us to flee the planet and remain on refuge ships for hundreds of years (2010's The Beast Below).

Time apparently heals all wounds, though, and by the 51st century, the planet had recovered – only to suffer the one-two punch of new Ice Age and World War VI (1977's The Talons of Weng-Chiang). Talk about a rough time of it...

According to 1975's The Ark in Space, our old nemesis the solar flares bombarded Earth once again in 6087, leaving it uninhabitable for 10,000 years and forcing humanity to evacuate by starship again. (The inhabitants of outpost station Nerva Beacon eventually recolonised the planet.)

Somehow, we were back on fighting form by the year 200,000, with a population of 96 billion (that Nerve Beacon lot must've been busy) and Earth at the centre of what was known as the Fourth Great and Bountiful Human Empire, incorporating a million planets and species. It transpired, however, that the Empire was being manipulated by Dalek survivors of the Last Great Time War, who launched a second devastating attack on Earth in 200,100 (as documented in 2005's The Long Game and Bad Wolf/The Parting of the Ways).

There's now a rather significant gap in Doctor Who history when it comes to Earth – our next update comes courtesy of 1986's The Trial of a Time Lord: The Mysterious Planet, which reveals that in the year 2,000,000 Earth was transported two light-years from its proper position by the Time Lords – by this point, the few humans left surviving had devolved into primitive beings.

We're clearly a resilient bunch, though, and by the "57th segment of time" – thought to be around the year 10,000,000 – civilisation had been restored, though we were forced to leave Earth for a final time, over building fears that the planet would be consumed by the Sun (1966's The Ark).

We were apparently premature, however, since Earth actually survived in some form until the year 5 billion, only being destroyed by the expanding sun in 2005's The End of the World.

Quite the future we've got to look forward to, huh? The good news, at least, is that the human race itself outlived Earth and lasted right up until the end of the universe itself... at which point we were all transformed into the monstrous Toclafane! Hooray! (2007's Utopia/The Sound of Drums/Last of the Time Lords)

Getting back to Orphan 55, it's not entirely clear when Doctor Who's latest trip to a future Earth takes place, or how it fits into the previously established list of devastating events described above. Sometime in the 51st century, maybe? Post-World War VI?

It's important to remember, though, that this is only "one possible future" and the "the future is not fixed" – possibly much of what's outlined above no longer happened (or rather, will no longer happen) because of changes to history. Still, whatever eventually happens to Earth in the Whoniverse, it's fair to say the outlook is pretty bleak...

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