We first turn to this quote from the Japanese version of the game:
This planet WILL recoVER.
If only humans weren't here...…
And the new world of we robots WOULD be
constructed.
A country of iron...... a utopia with neither
hatred nor sorrow.
This has been interpreted as saying the planet can recover after a full scale attack on the planet by a Lavoid, but this makes no sense. Let's consider what we know:
The Mother Brain, whatever kind of program she may be, is insane, be it disrupted due to Lavos' attack or a virus or what have you, she has become something completely unlike what she originally was, the Mother Brain of the R-Y series factory, a program that most likely maintained the automated production of such robots.
The Mother Brain wants to create a world of only robots. She has been systimatically eliminating all human life remaining on the planet and most likely would go after other organic life next.
The Planet is dying. That's the whole reason it created the Gates in the first place, to save it from being killed by Lavos. The idea that the Planet would recover completely invalidates the whole point for the game, to save the Planet. If it was just humanity, then the Planet would not care all that much, especially since we see from Chrono Cross that when it comes to choosing between humanity and its own survival, the Planet chooses itself, as seen by its pulling of Dinopolis into the Keystone dimension to counterbalance Chronopolis.
So, if the Planet is dying, how could it recover? Take a look at a map of the ruined 2300 A.D.:
http://www.chronocompendium.com/images/wiki/1/14/2300_A.D..pngTake a long, hard look at the surface of the planet. Note the singular lack of any vegetation. Note the grey, acidic oceans most likely barren of life. Remember also that the only remaining organic life seen anywhere are the few humans in domes, a scattering of rats and a few mutated creatures that have most likely been feeding off of each other for the past three hundred years--hence why so few remain--and will probably starve themselves into extinction. With the Mother Brain eliminating the humans and the mutants eliminating each other, the rats have nothing to feed on and will also perish. Also, remember that on the world map during play the atmosphere is constantly filled with swirling dust and electrical storms. This dust presumeably would not make for decent air to breathe. (How unfortunate this was never indicated anywhere in the game.)
The simple fact is nothing apart from the one line by the Mother Brain indicates the Planet is capable of recovering, and indeed the idea goes against the entire rest of the game itself. What's more, the line lends itself to interpretation. It is my belief that the line was meant to indicate the Mother Brain wished to populate the world with robots and robots alone. The Planet itself would eventually die, but the dead surface would be inhabited for centuries by robots, or so the Mother Brain would like to have occur. Thusly, the Planet WILL die from a Lavoid attack, and cannot recover.
