The boy doesn't exist.The boy is just a hallucination spurred on by the man needing a reason to live. When Ely asks "Are you a little boy?", he's only thinking that because the man was talking to someone else. Notice Ely never talks directly to the boy, or vice-versa.
Conversely, the father doesn't exist.Or rather the father was dead at the start of the novel. The father is a mental construct/hallucination of the boy, helping him deal with living in a post-apocalyptic wasteland. Anytime something "bad" happens like stealing, killing, and so on, it's the father that does it. In reality, the boy is doing everything, but he imagines the father is doing these bad things to help him retain his grip on his humanity.
The Road is a sequel to the film Idiocracy.Not much to add to this one. This theory showed up over at The Onion AV Club and demanded to be shared.
Everyone really is Jesus in Purgatory.So there's an unspecified disaster that happened at some point before the book starts. It killed off trees, animals, cockroaches, sarcastic pimp-bots that look like Jude Law — and yet somehow a handful of humans lived through it. This is a huge clue that we're not supposed to take this as literally After The End; all the human characters are actually dead. The boy is actually an angel and he is helping the father ascend to Heaven (remember all that business about "carrying the light"). The father's death was actually his ascension, and the angel/boy will go on to save the people who show up at the very end.
Yellowstone caldera is the cause of the cataclysmyellow stone (or any supervolcano for that matter)is a good fit. it won't just effect America but it's capable of covering the WHOLE planet in dust and debris for years if not decades. that's long enough to starve the planet of sunlight, thus decimating vegetation and wild life.
Aliens have detonated a biological warhead to choke the planet to death, planning to terraform Earth after the indigenous life dies offPerhaps the warhead hit in the eastern hemisphere, thus North America only hearing the detonations and feeling the effects. Maybe the Aliens are already hard at work on the opposite side of the planet. Either way, the hopeful ending at the end of the book is in vain.
The cataclysm turned North America into No Man's LandThis is related to the Yellowstone theory, except that the rest of the world fares (relatively) better. Realizing that there's a snowball's chance in Hell of expecting survivors, the remaining nations cordoned off the continent. Apart from pointing satellites on the ruins, they're just waiting for the dust to finally settle.
The Planet is actually a partially glassed UNSC ColonySimilar to the above alien theory, This planet was a earth colony that got abandoned after the UNSC withdrew leaving the rest to die a slow and painful death along with the planet. Maybe it wasn't glassing perse' but maybe a Type of Depopulation Bomb. The Covenant didn't have time (or the resources after a previous battle) to glass it so they sloppily used another weapon and left.
They are "carrying the light"They're too lucky. Unoccupied bomb shelter? Abandoned beached yacht? And then the man dies and the boy is immediately rescued by the only other decent people ever? God has a plan for them. Or something.
The world isn't all dead.I mean, they travel across half of America, but there's more to Earth than just that. Africa? South America? Antartica? The Marianas Trench? I mean, the author keeps most of the book feasible, so I wouldn't be surprised if Greenland or Australia would have taken a pass. America (and likely China and most other major world superpowers) just got royally screwed with the crap end of the stick. That said, it wouldn't make the novel any less post-apocalyptic and depressing, as the boy probably won't ever hear of any surviving patches of Earth, even if they DID exist.
Man and Woman were anticipating the cataclysmNotice in the beginning they had tons of can goods. Then there was the Robert Duvall character saying "They said this would happen". Then there's that bunker were it looked like it might have been stocked in preparation of the impending cataclysm.
The family eventually ate their horseExactly What It Says on the Tin.
The family is no different than the cannibalsNo other people appearing in the book (with the possible exception of Ely, though his appearance is brief enough as to invite speculation) are altruistic- not only are there cannibals, there are "death cults", a potential child-molester, a man who attempts to steal their cart of belongings, and a man who shoots the father in the leg with a bow. The family has a similar self-interest, but is craftier about it, picking up the bereaved boy. Assuming the children of the family are the children of the adults, perhaps the boy is picked up to serve as food on the hoof, so to speak; and perhaps the children are in a similar situation to the boy, being picked up by the adults to be eaten later.
The Book of Eli takes place in the same universeThe bad thing that happened is pretty similar - but the worst was over by then, and the west fared better than the east.
There is a near-solid crust above the atmosphere at the time of the story.This situation is more extreme than a nuclear winter, and evrthing will eventually choke because of closed air circulation. It's also preventing useful light from getting to plants.